  United States Court of Appeals
      for the Federal Circuit
                ______________________

           POWER INTEGRATIONS, INC.,
              Plaintiff-Cross-Appellant

                           v.

         FAIRCHILD SEMICONDUCTOR
       INTERNATIONAL, INC., FAIRCHILD
       SEMICONDUCTOR CORPORATION,
      FAIRCHILD (TAIWAN) CORPORATION,
              Defendants-Appellants
             ______________________

                 2015-1329, 2015-1388
                ______________________

    Appeals from the United States District Court for the
District of Delaware in No. 1:08-cv-00309-LPS, Chief
Judge Leonard P. Stark.
                ______________________

              Decided: December 12, 2016
                ______________________

    FRANK E. SCHERKENBACH, Fish & Richardson, P.C.,
Boston, MA, argued for plaintiff-cross-appellant. Also
represented by CRAIG E. COUNTRYMAN, San Diego, CA;
MICHAEL R. HEADLEY, HOWARD G. POLLACK, Redwood
City, CA.

   BLAIR M. JACOBS, Paul Hastings LLP, Washington,
DC, argued for defendants-appellants. Also represented
2         POWER INTEGRATIONS    v. FAIRCHILD SEMICONDUCTOR



by STEPHEN B. KINNAIRD, CHRISTINA A. ONDRICK, PATRICK
J. STAFFORD.
               ______________________

    Before PROST, Chief Judge, SCHALL, and CHEN, Circuit
                         Judges.
CHEN, Circuit Judge.
    This appeal follows a ten-day jury trial in the District
of Delaware that resulted in verdicts that (1) Power
Integrations Inc.’s U.S. Patent Nos. 7,110,270 and
7,834,605 were neither anticipated nor obvious and were
not directly or indirectly infringed by Fairchild Semicon-
ductor International, Inc., Fairchild Semiconductor Cor-
poration, and Fairchild (Taiwan) Corporation (collectively,
Fairchild); (2) Power Integrations’ U.S. Patent Nos.
6,107,851 and 6,249,876 were not anticipated and were
directly and indirectly infringed by Fairchild;
(3) Fairchild’s U.S. Patent No. 7,259,972 was not obvious,
was infringed by Power Integrations under the doctrine of
equivalents, but was not literally infringed or indirectly
infringed by Power Integrations; and (4) Fairchild’s U.S.
Patent No. 7,352,595 was not anticipated and was not
infringed by Power Integrations. Following trial, the
district court granted Power Integrations’ motion for
judgment as a matter of law (JMOL) that Fairchild direct-
ly infringed the ’605 patent, but denied the parties’ other
JMOL motions and motions for a new trial. Power Inte-
grations, Inc. v. Fairchild Semiconductor Int’l, Inc., 935 F.
Supp. 2d 747 (D. Del. 2013) (JMOL Decision). The court
subsequently granted Power Integrations’ motion for a
permanent injunction and denied Fairchild’s motion for a
permanent injunction.        Power Integrations, Inc. v.
Fairchild Semiconductor Int’l, Inc., No. 1:08-cv-00309-
LPS, 2014 WL 2960035 (D. Del. June 30, 2014) (Perma-
nent Injunction Order); Power Integrations, Inc. v.
Fairchild Semiconductor Int’l, Inc., No. 1:08-cv-00309-
LPS (D. Del. June 16, 2014) (Dkt. No. 790). The district
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          3



court entered final judgment as to liability on January 13,
2015. Power Integrations, Inc. v. Fairchild Semiconductor
Int’l, Inc., No. 1:08-cv-00309-LPS (D. Del. Jan. 13, 2015)
(Dkt. No. 819). All damages claims were bifurcated by the
district court and remain pending.
    Fairchild appeals and Power Integrations cross-
appeals various decisions from the district court. 1 We
hold as follows:
   •   The jury’s verdict that the asserted claims of the
       ’876 patent were not anticipated by Martin 2 or
       Wang 3 is affirmed.
   •   Because the district court’s jury instruction incor-
       rectly stated the law on inducement, the jury’s ver-
       dict that Fairchild induced infringement of the
       asserted claims of the ’876 and ’851 patents is va-
       cated.
   •   The jury’s verdict that the asserted claims of the
       ’605 patent were not anticipated by Maige 4 is re-
       versed.
   •   The district court’s construction that the asserted
       claims of the ’972 patent require “sampling a volt-
       age from the auxiliary winding of the transformer
       when the transformer is discharging” is affirmed.




   1    Neither party appeals the jury’s verdicts on the
’270 and ’595 patents.
    2   U.S. Patent No. 4,638,417.
    3   Andrew C. Wang and Seth R. Sanders, Pro-
grammed Pulsewidth Modulated Waveforms for Electro-
magnetic Interference Mitigation in DC-DC Converters,
IEEE Transactions on Power Electronics, Vol. 8, No. 4
(Oct. 1993).
    4   U.S. Patent No. 4,763,238.
4          POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



    •   The jury’s verdict that the asserted claims of the
        ’972 patent would not have been obvious in view of
        Majid 5 is affirmed.
    •   The jury’s verdict that Power Integrations infringed
        the asserted claims of the ’972 patent under the
        doctrine of equivalents is reversed.
    •   The district court’s grant of Power Integrations’
        motion for a permanent injunction is vacated in
        view of the above holdings.
    •   The district court’s denial of Fairchild’s motion for
        a permanent injunction is moot in view of the above
        holdings.
    In sum, we affirm-in-part, reverse-in-part, and vacate-
in-part the final judgment entered by the district court
and remand for further proceedings.
                        BACKGROUND
    Power Integrations and Fairchild are direct competi-
tors in the power supply controller chip market. They
have engaged in a long-running and multi-fronted patent
dispute involving actions in at least the United States
District Courts for the District of Delaware 6 and the
Northern District of California, 7 as well as the United
States Patent and Trademark Office Patent Trial and




    5   U.S. Patent No. 5,956,242.
    6   See Power Integrations, Inc. v. Fairchild Semicon-
ductor Int’l, Inc., No. 1:08-cv-00309-LPS (D. Del. filed May
23, 2008); Power Integrations, Inc. v. Fairchild Semicon-
ductor Int’l, Inc., No. 1:04-cv-01371-LPS (D. Del. filed Oct.
20, 2004).
    7   See Power Integrations, Inc. v. Fairchild Semicon-
ductor Int’l, Inc., No. 3:09-cv-05235-MMC (N.D. Cal. filed
Nov. 4, 2009).
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          5



Appeal Board. 8 We are not unfamiliar with the parties or
their disputes. In fact, we have heard appeals of at least
two decisions that involved two of the very patents at
issue here. See Power Integrations, Inc. v. Lee, 797 F.3d
1318 (Fed. Cir. 2015) (vacating Patent Board’s decision
that claims of the ’876 patent were unpatentable as
anticipated); Power Integrations, Inc. v. Fairchild Semi-
conductor Int’l, Inc., 711 F.3d 1348 (Fed. Cir. 2013) (re-
viewing jury verdict on ’851 and ’876 patents, among
others).
    Power supplies are ubiquitous in modern society. An-
yone who has purchased an electronic device in recent
times—whether a cellular phone, computer, television, or
the like—is familiar with the different cords and plugs
provided to power and/or charge those devices. Some-
where in the cord/plug combination resides a power
supply. The power supply is often integrated into the
plug itself, as is the case with many cellular phones. In
other configurations, the power supply resides in a
standalone module, as with many laptop computers.




 Figure 1: Power supply       Figure 2: Power supply as


   8   See Power Integrations, Inc. v. Fairchild Semicon-
ductor Corp., No. 2015-00769, 2015 WL 9595648 (PTAB
Dec. 31, 2015); see also Ex parte Power Integrations, Inc.,
No. 2010-011021, 2010 WL 5244756 (BPAI Dec. 22, 2010).
6         POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



    integrated into plug          a standalone module

    The power supply does more than simply allow power
to flow from a wall outlet to the connected electronic
device. Power supplies serve the integral role of convert-
ing the power supplied by the wall outlet into a form the
electronic device can use. The power a wall outlet pro-
vides is of a relatively high voltage and uses alternating
current (AC). In contrast, electronic devices generally
require a relatively low voltage and direct current (DC).
These devices would likely be damaged if exposed to high-
voltage AC power. Power supplies convert the high-
voltage AC power supplied by the wall outlet into the low-
voltage DC power required by the electronic device. 9
    The controller chip is the “brains” of the power supply.
It ensures that the power supply functions properly. Over
time, controller chips have evolved to incorporate new
features that make power supplies smaller, cheaper, and
more efficient. The patents at issue in this appeal relate
to some of the features that have been incorporated into
modern controller chips.
              I.   The ’851 and ’876 Patents
    Power Integrations is the assignee of the ’851 and ’876
patents. These patents relate to “frequency jitter” in
power supplies.
    Modern power supplies operate in what is known as
“switched mode.” Switched-mode power supplies conserve
energy by rapidly switching between on and off states.
They differ from older, linear power supplies, which
remained in an on state. The switched-mode power
supply’s controller chip commands the alternating on/off



    9   For a more detailed explanation of AC and DC
power and the conversion between the two, see our prior
opinion in Power Integrations, 711 F.3d at 1357–58.
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR           7



states through the use of an oscillator. Prior art switch-
mode power supplies most often used a high-frequency
oscillator operating at a fixed frequency. ’851 patent,
1:22–26; ’876 patent, 1:12–18. The fixed, high-frequency
operation of the oscillator tended to inject noise in the
form of electromagnetic interference (EMI) into the power
supply at the specific frequency of the oscillator. This
noise would, in turn, impact the operation of downstream
and co-located components. ’851 patent, 1:22–40; ’876
patent, 1:19–33.
    The ’851 and ’876 patents claim circuits that “jitter”—
or vary—the frequency of the controller chip’s oscillator to
reduce the amount of EMI the switched-mode power
supply generates. ’851 patent, 3:43–48; ’876 patent, 1:66–
67. One form of jitter is captured in Figure 2 of the ’876
patent:




As shown in the figure, the oscillator frequency increases
by a fixed amount every eight clock cycles before resetting
after 128 clock cycles. By jittering the oscillator frequen-
cy—using a step function like the one shown above or
some other scheme—the power supply divides any EMI it
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          9



    The invention of the ’605 patent attempts to solve this
problem. It introduces a regulator to the current-limiting
circuit that steadily increases the current threshold
during the time the power supply is in an on state. ’605
patent, 1:51–59. This variable current limit is shown in
Figure 2 of the ’605 patent:




The square wave—labeled “Duty Cycle Max 15”—
represents the alternating on and off states of the power
supply: when the wave is high, the power supply is on;
when the wave is low, the power supply is off. The cur-
rent limit (i.e., “Intrinsic Current Limit 22”) steadily
increases throughout the period the power supply is on; it
decreases throughout the period the power supply is off.
    This increasing current limit provides advantages
over prior art power supplies. For instance, with this
improved design, an immediate surge in output current
will trip the current limit at a lower level. This offers
additional protection to downstream components without
impacting operation of the power supply at normal power
levels.
                   III. The ’972 Patent
    Fairchild is the assignee of the ’972 patent. The ’972
patent is a combination patent and claims a power supply
10        POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



that includes frequency jitter—similar to that claimed in
the ’851 and ’876 patents—and overcurrent protection—
similar to the claimed invention of the ’605 patent. ’972
patent, 1:9–12.
    However, the ’972 patent discloses an approach to
overcurrent protection that differs from that of the ’605
patent. Whereas the regulator claimed in the ’605 patent
monitored the power supply’s output voltage and current
at the actual output of the power supply, ’605 patent,
6:16–18, the power converter claimed in the ’972 patent
monitors the output voltage and current at what is known
as the “primary side” of the power supply’s transformer,
’972 patent, 2:42–46.
    This is best explained with reference to Figure 1 of
the ’972 patent:




The figure is a schematic diagram of a power supply. Id.
at 2:62–64. The transformer, labeled “10,” divides the
power supply. All circuitry to the left of transformer 10 in
the schematic is the “primary side” of the power supply;
all circuitry to the right of transformer 10 is the “second-
ary side” of the power supply. See id. at 2:64–66. Power
supplies use a transformer to isolate the input terminals
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR         11



of the power supply (VIN) from the output terminals (VO)
for safety and reliability reasons. Id. at 1:17–20.
    Prior art power supplies, like that claimed in the ’605
patent, monitored output voltage and/or current on the
secondary side of the power supply. Id. at 1:24–30. Such
a scheme required a regulator on the secondary side as
well as an opto-coupler to provide feedback from the
secondary side of the power supply to the primary side.
Id. at 1:30–33. The addition of these components in-
creased the size and cost of the power supply. Id.
    The power supply claimed in the ’972 patent, in con-
trast, controls the output power at the primary side of the
transformer based on feedback received on the primary
side. Id. at 2:42–46. The power supply thereby does not
require the secondary-side regulator or the opto-coupler
found on prior art devices. Id. at 2:50–51. As a result,
the power supply could be smaller in size and lower in
cost.
                  PROCEDURAL HISTORY
    Power Integrations filed suit against Fairchild on May
23, 2008 in the District of Delaware alleging that
Fairchild directly and indirectly infringed the ’851, ’876,
and ’270 patents.       Power Integrations subsequently
amended its complaint to add allegations that Fairchild
directly and indirectly infringed the ’605 patent.
Fairchild filed counterclaims alleging that Power Integra-
tions directly and indirectly infringed the ’972 and ’595
patents and U.S. Patent No. 7,061,780. Each party de-
nied the infringement allegations made against it and
alleged that all patents asserted against it were invalid
and/or unenforceable.
   The district court bifurcated the liability and damages
phases of the case prior to trial. A ten-day jury trial on
12        POWER INTEGRATIONS    v. FAIRCHILD SEMICONDUCTOR



liability commenced on April 11, 2012. 10 At the conclu-
sion of trial, the jury returned a mixed verdict. The jury
found all claims asserted by Power Integrations not
invalid. Specifically, the jury found claims 1 and 2 of the
’605 patent neither anticipated nor obvious; claims 6 and
7 of the ’270 patent neither anticipated nor obvious;
claims 1 and 21 of the ’876 patent not anticipated; and
claim 18 of the ’851 patent not anticipated.
    The jury found Fairchild liable for infringement of the
’876 and ’851 patents.        It found that:       Fairchild’s
SG5841J-type products did not literally infringe claims 1
or 21 of the ’876 patent but did infringe those claims
under the doctrine of equivalents; Fairchild’s FAN103-
type products literally infringed claims 1 and 21 of the
’876 patent; Fairchild induced others to infringe claims 1
and 21 of the ’876 patent; Fairchild’s SG5841J- and
SG6842J-type products literally infringed claim 18 of the
’851 patent; and Fairchild induced others to infringe claim
18 of the ’851 patent. The jury found that Fairchild did
not directly infringe or induce infringement of claims 1 or
2 of the ’605 patent or claims 6 or 7 of the ’270 patent.
     Turning to Fairchild’s patents, the jury found all as-
serted claims not invalid. In particular, the jury found
claims 6, 7, 18, and 19 of the ’972 patent not obvious and
claims 17 and 22 of the ’595 patent not anticipated. On
infringement, the jury found for Fairchild under a single
theory: Power Integrations infringed the asserted claims
of the ’972 patent under the doctrine of equivalents. The
jury found that Power Integrations did not literally in-
fringe those claims nor did it induce others to infringe
those claims. The jury found that Power Integrations did
not infringe the asserted claims of the ’595 patent literal-
ly, under the doctrine of equivalents, or by inducement.



     10 By the time of trial, the ’780 patent was no longer
at issue.
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR           13



    The parties filed a multitude of post-trial motions
challenging aspects of the jury’s verdict or seeking a new
trial. The district court granted Power Integrations’
motion for JMOL of direct infringement of the ’605 patent.
JMOL Decision, 935 F. Supp. 2d at 756. It denied all
other motions. Id. at 764.
     Later, the court granted Power Integrations’ motion
for a permanent injunction and enjoined “Fairchild from
selling, offering to sell, and importing the products found
at trial to infringe and those products ‘not colorably
different’ from them.” Permanent Injunction Order, 2014
WL 2960035, at *2. The district court denied Fairchild’s
motion for a permanent injunction.
    The district court entered final judgment as to liabil-
ity on January 13, 2015. Fairchild filed a timely appeal
and Power Integrations cross-appealed. We have jurisdic-
tion pursuant to 28 U.S.C. § 1295(a)(1).
                        DISCUSSION
     The parties raise twelve issues on appeal. The issues
can be categorized as follows: (1) challenges to the district
court’s construction of certain claim terms; (2) a challenge
to the district court’s jury instructions; (3) a challenge to
the verdict form adopted by the district court; (4) chal-
lenges to the district court’s denial of certain of the par-
ties’ motions for JMOL; (5) challenges to the district
court’s denial of certain of the parties’ motions for a new
trial; and (6) challenges to the district court’s grant or
denial of a party’s motion for a permanent injunction.
    We apply the framework established in Teva Pharma-
ceuticals U.S.A., Inc. v. Sandoz, Inc. when reviewing a
district court’s construction of a patent’s claims. 135 S.
Ct. 831, 835 (2015). Under that framework, we review
the district court’s ultimate claim construction de novo
with any underlying factual determinations involving
extrinsic evidence reviewed for clear error. Id. at 841–42.
14         POWER INTEGRATIONS    v. FAIRCHILD SEMICONDUCTOR



    We review “the legal sufficiency of jury instructions on
an issue of patent law without deference to the district
court.” DSU Med. Corp. v. JMS Co., Ltd., 471 F.3d 1293,
1304 (Fed. Cir. 2006) (en banc). “A jury verdict will be set
aside only if the jury instructions were ‘legally erroneous’
and the ‘errors had prejudicial effect.’” Ericsson, Inc. v. D-
Link Sys., Inc., 773 F.3d 1201, 1225 (Fed. Cir. 2014)
(quoting Sulzer Textil A.G. v. Picanol N.V., 358 F.3d 1356,
1363 (Fed. Cir. 2004)).
     We review the verdict form adopted by the district
court for an abuse of discretion. See Wyers v. Master Lock
Co., 616 F.3d 1231, 1248 (Fed. Cir. 2010) (“[I]t must be
left to the sound discretion of the trial court what form of
verdict to request of a jury.” (quoting Structural Rubber
Prods. Co. v. Park Rubber Co., 749 F.2d 707, 720 (Fed.
Cir. 1984))).
     “We review the denial of a motion for JMOL . . . under
the law of the pertinent regional circuit. The Third Cir-
cuit exercises plenary review of a denial of JMOL, apply-
ing the same standard as the district court.” Siemens
Med. Sols. USA, Inc. v. Saint-Gobain Ceramics & Plastics,
Inc., 637 F.3d 1269, 1277–78 (Fed. Cir. 2011) (citations
omitted). “To prevail on a renewed motion for JMOL
following a jury trial, a party must show that the jury’s
findings, presumed or express, are not supported by
substantial evidence or, if they were, that the legal con-
clusion(s) implied by the jury’s verdict cannot in law be
supported by those findings.” Pannu v. Iolab Corp., 155
F.3d 1344, 1348 (Fed. Cir. 1998) (internal quotation
marks and citations omitted).
     “In reviewing a district court’s disposition of . . . a new
trial motion, this court applies the law of the regional
circuit where the district court sits.” Bettcher Indus., Inc.
v. Bunzl USA, Inc., 661 F.3d 629, 638 (Fed. Cir. 2011)
(citation omitted). The Third Circuit “review[s] a district
court’s grant or denial of a new trial motion by applying
the deferential ‘abuse of discretion’ standard to the rul-
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR            15



ing.” Olefins Trading, Inc. v. Han Yang Chem Corp., 9
F.3d 282, 289 (3d Cir. 1993).
    We review a district court’s ultimate decision to grant
or deny a permanent injunction for an abuse of discretion.
Apple, Inc. v. Samsung Elecs. Co., Ltd., 809 F.3d 633, 639
(Fed. Cir. 2015). We review the district court’s conclu-
sions on each of the underlying factors set forth in eBay
Inc. v. MercExchange, LLC, 547 U.S. 388 (2006), for an
abuse of discretion and its underlying factual findings for
clear error. Apple, 809 F.3d at 639.
    For simplicity, we address all issues associated with a
particular patent—or group of patents—together. We
therefore depart from our normal practice and intersperse
the issues raised in Fairchild’s appeal with the issues
raised in Power Integrations’ cross-appeal as necessary.
     I.   The ’851 and ’876 Patents (Frequency Jitter)
    Fairchild commits much of its briefing to its argument
that it is entitled to JMOL that it did not induce in-
fringement of the ’851 and ’876 patents or, at the very
least, that it is entitled to a new trial on the issue. Before
reaching the jury’s induced infringement verdict, howev-
er, we must first address Fairchild’s argument that claims
1 and 21 of the ’876 patent are invalid as anticipated. 11
               A. Validity of the ’876 Patent
    The jury found that neither Martin nor Wang antici-
pated claims 1 and 21 of the ’876 patent. The ’876 patent
claims a “frequency jittering” circuit used in switched-
mode power supplies to reduce EMI emissions produced
by the power supply. ’876 patent, Abstract. Claim 1
reads as follows:




    11 Fairchild does not appeal the jury’s verdict that
claim 18 of the ’851 patent was not invalid as anticipated.
16         POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



     1. A digital frequency jittering circuit for varying
     the switching frequency of a power supply, com-
     prising:
        an oscillator for generating a signal hav-
        ing a switching frequency, the oscillator
        having a control input for varying the
        switching frequency;
        a digital to analog converter coupled to the
        control input for varying the switching
        frequency; and
        a counter coupled to the output of the oscil-
        lator and to the digital to analog converter,
        the counter causing the digital to analog
        converter to adjust the control input and
        to vary the switching frequency.
Id. at 8:42–53 (emphases added). Claim 21 is similar. It
too is directed to a “frequency jittering circuit.” Id. at
9:55–65. It includes a limitation analogous to the one
emphasized above in claim 1: “a counter coupled to the
output of the oscillator and to the one or more current
sources.” Id. at 9:64–65.
     Martin and Wang each disclose a controller circuit
used to reduce the EMI signature associated with a power
supply’s oscillator. See Martin, 1:55–56; Wang at 585.
The circuits accomplish this reduction by varying the
oscillator frequency through the use of a pseudo-random
code stored in read-only memory (ROM). See, e.g., Mar-
tin, 1:53–55. The below figure from Martin is exemplary:
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR           17




Martin, Fig. 1. In this circuit, counter 10 acts as an index
to EPROM 11. As the output of counter 10 increases, it
accesses the pseudo-random code value stored at the
corresponding address of EPROM 11. Id. at 2:39–44.
This value is outputted to digital-to-analog converter 12,
which in turn drives the circuit’s oscillator (i.e., VCO 13).
Id. at 2:44–49. The result is an oscillator with a frequen-
cy that varies according to the pseudo-random code stored
in EPROM 11.
    At trial, Power Integrations disputed Fairchild’s ar-
gument that Martin and Wang anticipated claims 1 and
21. It argued to the jury that the invention of the ’876
patent differed from the prior art references in at least
two key ways: (1) the circuits of Martin and Wang do not
vary about a “target frequency” as required by the district
court’s construction of “frequency jittering;” and (2) the
counters of Martin and Wang are not “coupled” to the
digital-to-analog converter as the district court construed
that term. The jury agreed and found that the claims
were not anticipated by Martin or Wang.
     We find that the jury’s verdict was supported by sub-
stantial evidence. The district court construed “frequency
jittering” to mean “varying the switching frequency of a
switch mode power supply about a target frequency in
order to reduce electromagnetic interference.” Power
Integrations, Inc. v. Fairchild Semiconductor Int’l, Inc.,
18        POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



No. 1:08-cv-00309-LPS, 2009 WL 4928029, at *20 (D. Del.
Dec. 18, 2009) (Claim Construction Order). 12 Fairchild
does not challenge this construction. Rather, it contends
that the claim limitation was disclosed in the prior art,
using an argument akin to the symmetric property in
mathematics. 13 Fairchild first notes that one type of
target frequency (“a”) disclosed in the ’876 patent is an
average frequency (“b”). It next contends that one can
take the pseudo-random frequencies used in Martin and
Wang and calculate an average frequency (“b”). It finally
argues that if the ’876 patent’s target frequency can be an
average frequency (i.e., a = b), then Martin’s and Wang’s
average frequency (that Fairchild proposed can be calcu-
lated) must be a target frequency (i.e., b = a).
     While Fairchild’s argument is creative, it fails to ac-
count for the temporal aspect of the district court’s claim
construction. The district court explained that “frequency
jittering” requires “varying the switching frequency of a
switch mode power supply about a target frequency in
order to reduce electromagnetic interference.” Id. Under
this construction, the claimed circuit—or its designer—
must have a priori knowledge of the target frequency in
order to vary the switching frequency about that target
frequency. See id. (explaining that the patent specifica-
tion “refer[s] to varying the switching frequency about a
narrow, known, or fixed range of frequencies in order to
reduce EMI”). As the district court correctly noted,
Fairchild’s proposed calculation of Martin’s and Wang’s
average frequency is done entirely “after the fact.” JMOL
Decision, 935 F. Supp. 2d at 761 (“Calculating an average
frequency after the fact does not teach one of skill in the
art how to vary the switching frequency, and does not


     12 The district court adopted then-Magistrate Judge
Stark’s Report and Recommendation Regarding Claim
Construction on July 20, 2010. J.A. 49–50.
   13   Under the symmetric property, if a = b then b = a.
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          19



produce the desired result of reducing electromagnetic
interference.”). Neither reference teaches use of a known
target frequency about which switching frequencies are
varied. Therefore, substantial evidence supports the
jury’s findings that the references do not anticipate claim
1 or 21.
    Martin and Wang likewise do not teach the “coupled
to” limitations of claims 1 and 21. The district court
construed “coupled” to mean that “two circuits are coupled
when they are connected such that voltage, current or
control signals pass from one to another.” J.A. 17137.
Martin and Wang each disclose a circuit that includes a
counter linked to a digital-to-analog converter by way of a
ROM. See Martin, Fig. 1; Wang at 604. The ROM takes
the output of the upstream counter as its input. Martin,
2:22–24; Wang at 604. It then outputs a different, stored
value to the digital-to-analog converter. Martin, 2:29–32;
Wang at 604. The addition of the ROM thereby ensures
that no “voltage, current or control signals pass from” the
counter to the digital-to-analog converter. In other words,
the ROM “decouples” the counter from the digital-to-
analog converter. As such, substantial evidence supports
the jury verdict that neither Martin nor Wang anticipates
claim 1 or 21. The district court therefore correctly denied
Fairchild’s JMOL motion.
  B. Induced Infringement of the ’851 and ’876 Patents
    The jury found that Fairchild’s SG5841J- and
SG6842J-type products literally infringed claim 18 of the
’851 patent; its SG5841J-type products infringed claims 1
and 21 of the ’876 patent under the doctrine of equiva-
lents; and its FAN103-type products literally infringed
claims 1 and 21 of the ’876 patent. The jury further found
that Fairchild induced others to infringe these claims.
Fairchild does not appeal the jury’s direct infringement
verdicts. It does appeal the jury’s indirect infringement
verdicts.
20        POWER INTEGRATIONS    v. FAIRCHILD SEMICONDUCTOR



    Fairchild raises three issues with respect to the jury’s
induced infringement verdict. Fairchild first argues that
the verdict should be reversed because its foreign sales of
and sales activities related to the infringing products
cannot constitute specific intent to bring about infringe-
ment in the United States. Alternatively, Fairchild
argues that the verdict should be vacated because the jury
was improperly instructed that Fairchild need not suc-
cessfully induce a third party to infringe to be liable for
induced infringement. Finally, Fairchild argues that the
district court’s failure to include interrogatories on the
verdict form requiring identification of direct infringers is
a separate ground to vacate the jury verdict.
    We agree with Fairchild that the district court’s jury
instruction misstated the law on induced infringement in
a way that prejudiced Fairchild. We therefore vacate the
jury’s verdict. Because we do not find that the record as a
whole requires a finding of non-infringement as a matter
of law, we do not go further and, as Fairchild requests,
enter judgment in its favor. Our decision to vacate the
jury verdict due to the improper jury instruction renders
Fairchild’s argument with respect to the verdict form
moot. 14



     14 While we do not reach Fairchild’s appeal on the
verdict form, we are not unsympathetic to the Seventh
Amendment concerns Fairchild raises. On remand, we
“le[ave] to the sound discretion of the trial court what
form of verdict to request of a jury.” Wyers, 616 F.3d at
1248. We nonetheless note that the court’s decision to
bifurcate liability and damages in this case does raise the
possibility that both the liability jury and the damages
jury will be asked to determine which of Fairchild’s cus-
tomers were induced to infringe by Fairchild. Such a
result may run afoul of the Seventh Amendment. See
Blyden v. Mancusi, 186 F.3d 252, 268 (2d Cir. 1999)
POWER INTEGRATIONS      v. FAIRCHILD SEMICONDUCTOR       21



                   i.     Jury Instruction
    Induced infringement is defined in 35 U.S.C. § 271(b):
“Whoever actively induces infringement of a patent shall
be liable as an infringer.”
    In the lead-up to trial, Power Integrations and
Fairchild proposed competing jury instructions on induced
infringement. Fairchild’s proposed instruction tracked
the then-current Federal Circuit Bar Association model,
while Power Integrations’ proposal was a variation of an
instruction given in a prior trial in the District of Dela-
ware. The parties’ dispute continued through trial, with
each party advocating for its proposed instruction and
objecting to its opponent’s proposed instruction.
    The district court adopted an instruction that largely
tracked the one proposed by Power Integrations. It read:
   Each party alleges that the other is liable for in-
   fringement by actively inducing others to directly
   infringe the patents in suit. The direct infringe-
   ment may either be literal or under the doctrine of
   equivalents. A party induces patent infringement
   if it purposefully causes, urges, or encourages an-
   other to use a product in a manner that infringes
   an asserted claim. Inducing infringement cannot
   occur unintentionally.
   A party is liable for active inducement only if the
   patent owner proves by a preponderance of the ev-
   idence that:




(“Issues may be divided and tried separately, but a given
issue may not be tried by different successive juries.”
(citing Byrd v. Blue Ridge Rural Elec. Coop., 356 U.S. 525,
537–38 (1958); Gasoline Prods. Co. v. Champlin Ref. Co.,
283 U.S. 494, 500 (1931))).
22         POWER INTEGRATIONS    v. FAIRCHILD SEMICONDUCTOR



         1. the party took some action during the
            time the patents in suit were in force
            intending to encourage or assist ac-
            tions by others;
         2. the party was aware of the patent and
            knew that the acts, if taken, would
            constitute infringement of that patent
            or the party believed there was a high
            probability that the acts, if taken,
            would constitute infringement of the
            patent but deliberately avoided con-
            firming that belief; and
         3. use by others of the party’s product in-
            fringes one or more of the asserted
            claims of the patent.
     In order to establish active inducement of in-
     fringement, it is not sufficient that others directly
     infringe the claim. Nor is it sufficient that the
     party accused of infringement was aware of the
     acts by others that directly infringe. Rather, in
     order to find inducement, you must find that the
     party accused of infringement intended others to
     use its products in at least some ways that would
     infringe the asserted claims of the patent. How-
     ever, that infringement need not have been actually
     caused by the party’s actions. All that is required
     is that the party took steps to encourage or assist
     that infringement, regardless of whether that en-
     couragement succeeded, or was even received.
     Intent to encourage or assist the acts that consti-
     tute direct infringement must be proven by evi-
     dence of active steps taken to encourage direct
     infringement, such as providing products, adver-
     tising any infringing use, or instructing how to
     engage in any use that is infringing.
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR           23



    Proof of intent to induce infringement may be
    based on circumstantial evidence, rather than di-
    rect evidence.
J.A. 510–11 (emphasis added).
    This instruction left the jury with the incorrect under-
standing that a party may be liable for induced infringe-
ment even where it does not successfully communicate
with and induce a third-party direct infringer. 15 The
Supreme Court has explained that the term “induce” as it
is used in § 271(b) “means ‘[t]o lean on; to influence; to
prevail on; to move by persuasion.” Global-Tech Appli-
ances, Inc. v. SEB S.A., 563 U.S. 754, 760 (2011) (altera-
tion in original) (citations omitted). Each definition
requires successful communication between the alleged
inducer and the third-party direct infringer.



    15  Power Integrations argues that Fairchild did not
preserve this issue for appeal. Appellee’s Opening Br. 44–
46. We disagree. Fairchild repeatedly and consistently
argued to the district court—in the context of the jury
instructions and the verdict form—that a finding of
induced infringement required evidence that Fairchild
actually induced third-party direct infringers. See, e.g.,
J.A. 16946–47 (1941:18–1942:4).* Moreover, Fairchild
expressly objected to the jury instruction on induced
infringement. J.A. 17179 (2495:6–9) (“Your Honor, we
want to make sure we state on the record that we object
to Jury Instruction 4.5 and we are very interested to see
how we sort this out at a later point in time, depending on
the verdict.”).
    * The trial transcript included in the joint appendix
contains four transcript pages for each single page of the
joint appendix. Whenever citing to the trial transcript,
we cite to both the joint appendix page(s) (i.e., J.A. #####)
and the specific trial transcript page(s) and line(s) (i.e.,
PPPP:LL–PPPP:LL).
24        POWER INTEGRATIONS    v. FAIRCHILD SEMICONDUCTOR



    We have further held that “[t]o prevail under a theory
of indirect infringement, [plaintiff] must first prove that
the defendants’ actions led to direct infringement of the
[patent-in-suit].” Dynacore Holdings Corp. v. U.S. Philips
Corp., 363 F.3d 1263, 1274 (Fed. Cir. 2004) (citation
omitted); see also DSU Med. Corp., 471 F.3d at 1304
(“[T]he plaintiff has the burden of showing that the al-
leged infringer’s actions induced infringing acts . . . .”
(internal quotation marks and citation omitted)); Crystal
Semiconductor Corp. v. TriTech Microelecs. Int’l, Inc., 246
F.3d 1336, 1351 (Fed. Cir. 2001) (induced infringement
occurs only “if the party being induced directly infringes
the patent” (citation omitted)).
     Under this precedent, a finding of induced infringe-
ment requires actual inducement. The inducement may
be proven via circumstantial evidence. See MEMC Elec.
Materials, Inc. v. Mitsubishi Materials Silicon Corp., 420
F.3d 1369, 1380 (Fed. Cir. 2005) (finding “sufficient
circumstantial evidence for a reasonable jury to conclude
that [defendant] was not only aware of the potentially
infringing activities in the United States by [a third-party
infringer], but also that [defendant] intended to encourage
those activities” (citations omitted)). But the jury must
still find that it occurred. The jury instruction incorrectly
stated that liability exists even where no inducement
actually occurred. This is contrary to the law.
    Power Integrations attempts to salvage the jury in-
struction—and, by extension, the jury verdict—by claim-
ing that the disputed portion of the instruction related to
Fairchild’s intent to induce a third-party direct infringer,
not whether Fairchild actually induced a third party. It
cites the Supreme Court’s decision in Grokster 16 and our




     16 Metro-Goldwyn-Mayer Studios Inc. v. Grokster,
Ltd., 545 U.S. 913 (2005).
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR            25



decision in Ricoh 17 for the proposition that “a defendant’s
acts to encourage direct infringement are probative of an
unlawful intent, even if customers do not learn of them or
the acts don’t cause the customers’ direct infringement.”
Appellee’s Opening Br. 46. Power Integrations’ statement
of the law is correct. However, it is irrelevant here. The
district court instructed the jury that “[direct] infringe-
ment need not have been actually caused by the [alleged
inducer]’s actions. All that is required is that the party
took steps to encourage or assist that infringement,
regardless of whether that encouragement succeeded, or
was even received.” J.A. 510. Nothing in this statement
suggests that it applies to simply Fairchild’s intent to
induce infringement. Rather, it expressly misstates the
law on actual inducement. See Dynacore, 363 F.3d at
1274 (“To prevail under a theory of indirect infringement,
Dynacore must first prove that defendants’ actions led to
direct infringement of the [patent-in-suit].”).
    We conclude that the district court’s instruction mis-
stated the law of induced infringement. As discussed
more fully below, Power Integrations’ claim for induced
infringement was a close call. Therefore, we cannot say
that the instruction did not tip the scales in favor of
Power Integrations at trial. We thus vacate the jury’s
verdict that Fairchild induced infringement of the ’851
and ’876 patents. See Ericsson, 773 F.3d 1201, 1225 (Fed.
Cir. 2014) (“A jury verdict will be set aside only if the jury
instructions were ‘legally erroneous’ and the ‘errors had
prejudicial effect.’” (citation omitted)).
                      ii. Jury Verdict
    While we have already determined that the flawed ju-
ry instruction requires that we vacate the jury’s verdict,
we must still address Fairchild’s argument that it is


    17 Ricoh Co., Ltd. v. Quanta Computer, Inc., 550
F.3d 1325 (Fed. Cir. 2008).
26        POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



entitled to JMOL of no induced infringement. After all, if
Power Integrations did not present sufficient evidence to
allow a reasonable jury to find in its favor, a new trial on
induced infringement would be unnecessary—and im-
proper—regardless of the jury instruction given by the
district court. See Verizon Servs. Corp. v. Cox Fibernet
Va., Inc., 602 F.3d 1325, 1337–38 (Fed. Cir. 2010) (“In
reviewing the jury verdict of obviousness, we review
whether the jury was correctly instructed on the law, and
whether there was substantial evidence whereby a reason-
able jury could have reached its verdict upon application
of the correct law to the facts, recognizing that invalidity
must be proved by clear and convincing evidence.” (em-
phasis added) (citation omitted)). Because the evidentiary
record permits more than one reasonable finding on
induced infringement, we cannot say that, had the jury
been instructed properly, the jury’s verdict would have
lacked substantial supporting evidence. Therefore, we do
not enter judgment in favor of Fairchild.
    “To prove inducement of infringement, the patentee
must []show that the accused inducer took an affirmative
act to encourage infringement with the knowledge that
the induced acts constitute patent infringement.” Astor-
net Techs. Inc. v. BAE Sys., Inc., 802 F.3d 1271, 1279
(Fed. Cir. 2015) (quoting Info-Hold, Inc. v. Muzak LLC,
783 F.3d 1365, 1372 (Fed. Cir. 2015)). In other words,
Power Integrations was required to prove that: (1) a third
party directly infringed the asserted claims of the ’851
and ’876 patents; (2) Fairchild induced those infringing
acts; and (3) Fairchild knew the acts it induced constitut-
ed infringement.
    Fairchild does not seriously dispute that Power Inte-
grations proved infringement of the ’851 and ’876 patents
by third parties. Power Integrations presented evidence
that it purchased at least three products containing
infringing Fairchild chips in the United States: an HP
printer packaged with an Astec power supply that con-
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          27



tained an infringing Fairchild SG6846A controller chip;
an Acer notebook computer packaged with a Lite-On
power supply that contained an infringing Fairchild
LTA703S controller chip; and a Samsung notebook com-
puter packaged with a power supply that contained an
infringing SG6842J controller chip. Fairchild makes no
argument that these controller chips do not necessarily
infringe the relevant claims of the ’851 and ’876 patents if
made, used, or sold in the United States. See Appellants’
Opening Br. 19 (conceding that Power Integrations proved
“limited instances . . . of direct infringement by third-
party sellers”).
    Fairchild likewise does not seriously dispute it knew
that importation, use, and sale of these controller chips in
the United States constituted infringement of the ’851
and ’876 patents. In the single paragraph of argument on
this issue in its briefing, Fairchild cites the conclusory
trial testimony of one of its executives that he and his
sales team told customers that “we don’t infringe the
Power Integrations patents” and makes the equally
conclusory statement that “Fairchild presented strong
non-infringement defenses as to both patents.” Appel-
lants’ Opening Br. 32–33 (quoting J.A. 16787 (1470:3)).
Fairchild needs more to meet its burden of “show[ing]
that the jury’s findings . . . are not supported by substan-
tial evidence,” as it must to succeed on appeal. Pannu,
155 F.3d at 1348. This is particularly true considering
this court has already found that “Fairchild competed
with Power Integrations by reverse engineering and
copying of Power Integrations’ products” and that
“Fairchild fostered a corporate culture of copying” with
respect to at least the ’876 patent. Power Integrations,
711 F.3d at 1369.
    Fairchild’s appeal instead focuses on whether sub-
stantial evidence supports the jury’s verdict that Fairchild
actually induced third-party direct infringement.
Fairchild explains that it sells its controller chips over-
28        POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



seas into a worldwide distribution system with no
knowledge of where its chips will ultimately end up. It
contends that, because it sells the same chips for use in
foreign and domestic markets, its sales activities are
market agnostic and Power Integrations “marshaled no
evidence that Fairchild took affirmative steps to encour-
age incorporation of the accused products into U.S.-bound
products with the specific intent to induce infringement.”
Appellants’ Opening Br. 25.
    We disagree with Fairchild’s characterization of the
evidence. Power Integrations, in fact, introduced signifi-
cant—though not necessarily overwhelming—evidence
that would allow a jury to find that Fairchild took affirm-
ative acts to induce third parties to import its products
into the United States. As examples, Power Integrations
presented evidence that: Fairchild designed its controller
chips to meet certain United States energy standards,
including Energy Star and those imposed by the Califor-
nia Energy Commission (CEC), J.A. 16400 (569:17–
571:20), J.A. 16500–01 (795:9–796:3), J.A. 16523–24
(887:25–891:10), J.A. 16778 (1435:8–1437:18), J.A. 25065;
Fairchild competed for business it knew was directed to
the United States, J.A. 16929 (1871:25–1873:1), J.A.
16931 (1878:4–1879:8); J.A. 24492, J.A 24495; Fairchild
provided demonstration boards containing the infringing
controller chips to customers and potential customers in
the United States, J.A. 16514 (848:19–849:10), J.A. 16524
(889:22–890:5), J.A. 16794 (1498:25–1499:3); Fairchild’s
website enabled customers to locate a United States-
based distributor that sold Fairchild’s infringing control-
ler chips, J.A. 16927 (1864:1–1866:1); Fairchild main-
tained a technical support center in the United States
that provided support for the infringing controller chips to
customers based in the United States, J.A. 16402 (579:13–
580:6), J.A. 24174; and Fairchild’s standard terms and
conditions indemnified customers against claims for
infringement of United States patents, J.A. 16773
(1416:1–24).
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          29



     Fairchild endeavors to explain away or otherwise di-
minish the value of each piece of evidence presented by
Power Integrations. For instance, Fairchild argues that
its provision of demonstration boards was “ordinary
commercial activity” that cannot lead to liability for
induced infringement because its controller chips have
non-infringing uses. Appellants’ Opening Br. 25 (citing
Grokster, 545 U.S. at 937). But, Fairchild ignores that the
only non-infringing use of its controller chips was foreign
use.     Power Integrations introduced evidence that
Fairchild shipped demonstration boards to customers and
potential customers in the United States. The jury was
therefore entitled to consider this evidence in determining
if Fairchild induced infringement in the United States.
     As another example, Fairchild argues that its promo-
tion of its products as compliant with certain energy
efficiency standards—such as Energy Star and those
imposed by CEC—that originated in the United States
cannot constitute inducing acts, because the standards
had been adopted by many other countries. Appellants’
Opening Br. 29–31. But, the jury heard testimony, in-
cluding from Fairchild’s own witnesses, that the Energy
Star and CEC standards are United States standards.
See, e.g., J.A. 16467 (660:21–25); J.A. 16500 (795:9–23);
J.A. 16523–24 (887:22–888:1); J.A. 16524 (890:25–891:10).
The jury also heard testimony that, while other countries
initially adopted the United States energy efficiency
standards, certain countries had established different,
more stringent standards of their own. J.A. 16778
(1435:3–20). In light of this testimony, it was reasonable
for a juror to view Fairchild’s promotion of its products as
Energy Star and/or CEC compliant as targeted to the
United States market, and therefore relevant to induce-
ment.
    Rather than addressing each of Fairchild’s remaining,
discrete attacks on Power Integrations’ evidence of in-
ducement, we note that Fairchild misses the forest for the
30        POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



trees. While each piece of evidence may not individually
be sufficient to establish Fairchild’s liability, see, e.g.,
MEMC, 420 F.3d at 1378–79 (holding that an indemnity
provision alone cannot establish intent to induce in-
fringement unless “the primary purpose” of the provision
was to induce infringement), the evidence as a whole
provided the jury substantial evidence upon which to find
inducement by Fairchild, see, e.g., Lucent Techs., Inc. v.
Gateway, Inc., 580 F.3d 1301, 1323 (Fed. Cir. 2009) (“Hav-
ing perused the evidence, we agree with [defendant] that
the evidence is not strong, but we are not persuaded that
the jury was unreasonable in finding that [defendant]
possessed the requisite intent to induce at least one user
of its products to infringe the claimed methods.”).
    Fairchild offers an alternative theory why it is enti-
tled to JMOL of no induced infringement: Power Integra-
tions failed to establish a nexus between Fairchild’s
allegedly inducing acts and the acts of direct infringement
Power Integrations proved at trial. It contends that
Power Integrations introduced evidence of only three acts
of direct infringement—sales of an HP printer, Acer
notebook computer, and Samsung notebook computer
containing infringing Fairchild controller chips—and that
Power Integrations was required to present evidence that
Fairchild specifically induced HP, Acer, Samsung, or the
retailers from which Power Integrations purchased the
infringing products to incorporate the infringing control-
ler chips into products bound for the United States.
Appellants’ Opening Br. 20 (“[Power Integrations] put on
no evidence of the provenance of the chips in these devic-
es, or that Fairchild induced Best Buy, Wal-Mart, HP,
Acer, Samsung, or any downstream reseller to incorporate
accused chips into U.S.-bound products with specific
intent to bring about these U.S. infringements.”).
    We find this argument without merit. As detailed
above, Power Integrations presented substantial evidence
that Fairchild took affirmative acts to induce third parties
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          31



to import its controller chips into the United States
wherein—Fairchild does not seriously dispute—the chips
necessarily infringed. While none of this evidence can be
directly linked to the particular HP printer, Acer notebook
computer, or Samsung notebook computer Power Integra-
tions introduced at trial as representative acts of direct
infringement, it was sufficient to allow the jury to find
that Fairchild had induced its customers (including HP,
Acer, and Samsung) to infringe as a class. This is all that
we require. See Dynacore, 363 F.3d at 1274–75 (con-
trasting the proof required to prove individual acts of
induced infringement as opposed to inducement of “an
entire category of infringers (e.g., the defendant’s custom-
ers)”). Indeed, we have affirmed induced infringement
verdicts based on circumstantial evidence of inducement
(e.g., advertisements, user manuals) directed to a class of
direct infringers (e.g., customers, end users) without
requiring hard proof that any individual third-party
direct infringer was actually persuaded to infringe by that
material. See, e.g., Ericsson, 773 F.3d at 1220, 1222
(affirming jury’s induced infringement verdict where
defendant advertised compliance with an infringing
standard); Arthrocare Corp. v. Smith & Nephew, Inc., 406
F.3d 1365, 1377 (Fed. Cir. 2005) (affirming jury’s induced
infringement verdict where defendant distributed “sales
literature” and “manuals” that instructed how to use
product in infringing manner); cf. Liquid Dynamics Corp.
v. Vaughan Co., Inc., 449 F.3d 1209, 1223 (Fed. Cir. 2006)
(affirming infringement verdict under 35 U.S.C. § 271(f)
and explaining that distribution of “engineering manual
. . . replete with examples” of infringing use was substan-
tial evidence of inducement).
    Accordingly, having reviewed the record as a whole,
we cannot conclude that no reasonable jury—if instructed
properly—could have found that Fairchild induced in-
fringement of the ’851 and ’876 patents.
32         POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



          II. The ’605 Patent (Current Limiting)
    Fairchild appeals the jury’s verdict that claims 1 and
2 of the ’605 patent were not anticipated by Maige. Power
Integrations cross-appeals and argues that it is entitled to
a new trial on induced infringement due to certain preju-
dicial statements made by Fairchild during trial. We find
the jury’s verdict that Maige did not anticipate claims 1
and 2 of the ’605 patent unsupported by substantial
evidence. We therefore reverse the jury’s verdict of no
anticipation. As a result, Power Integrations’ cross-
appeal is moot.
    The ’605 patent claims “[a] power supply regulator in-
cluding a variable current limit threshold that increases
during an on time of a switch.” ’605 patent, Abstract.
Claim 1 reads as follows:
     1. A power supply regulator, comprising:
        a comparator having a first input coupled
        to sense a voltage representative of a cur-
        rent flowing through a switch during an
        on time of the switch, the comparator hav-
        ing a second input coupled to receive a var-
        iable current limit threshold that increases
        during the on time of the switch;
        a feedback circuit coupled to receive a
        feedback signal representative of an out-
        put voltage at an output of a power sup-
        ply; and
        a control circuit coupled to generate a con-
        trol signal in response to an output of the
        comparator and in response to an output
        of the feedback circuit, the control signal
        to be coupled to a control terminal of the
        switch to control switching of the switch.
Id. at 6:10–27 (emphasis added). Claim 2 depends from
claim 1 and further requires “an oscillator having a first
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR         33



output to generate a sawtooth waveform, wherein the
variable current limit threshold is generated in response
to the sawtooth waveform.” Id. at 6:28–29.
    Maige describes “[a] protection device for switch mode
power supplies.” Maige, Abstract. Like the regulator
claimed in the ’605 patent, Maige’s protection device uses
a current limit threshold to protect downstream compo-
nents in the event of a power surge. The specific type of
threshold employed by Maige depends on the mode of the
protection device. When the protection device is in start-
up mode, Maige uses “soft start circuitry” to introduce an
increasing current threshold that prevents a large in-rush
of current. When the protection device is in its normal
operation mode, Maige uses a fixed current limit.
    At trial, the parties disputed whether Maige discloses
“a variable current limit threshold that increases during
the on time of the switch.”         ’605 patent, 6:11–15.
Fairchild presented the testimony of its expert, Dr. Gu-
Yeon Wei, that Maige’s current threshold increased
throughout the period of start-up—during which the
device alternates between on and off states—and thereby
satisfied the limitation. Power Integrations countered
with the testimony of its own expert, Dr. Arthur Kelley.
Dr. Kelley testified that Maige’s current threshold did not
increase “during the on time of the switch” as required by
the claim and presented test data in the form of an oscil-
loscope screen capture to show that the current threshold
remained constant during start-up. The jury sided with
Power Integrations and found that Maige did not antici-
pate claims 1 and 2 of the ’605 patent.
    We find that the jury’s verdict is not supported by
substantial evidence. Dr. Kelley testified at trial that
(1) Maige’s current threshold increases “[d]uring the
whole process of startup,” J.A. 16907 (1785:4–14); and
(2) Maige’s power supply is on “for some period of time”
during startup, J.A. 16908 (1786:22–1787:4). Taken
together, Dr. Kelley’s testimony is a concession that
34         POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



Maige’s current threshold “increases during the on time of
the switch.”
    This is all that claims 1 and 2 require. Nothing in the
claims requires that the current threshold increase during
the power supply’s normal operation. Indeed, Dr. Kelley
testified to this effect at trial:
     Q. Okay. So you would agree with me, I hope,
     that there is nothing in Claim 1 that limits the
     operation to what is claimed here to normal condi-
     tions only. Right?
     A. Sure.
J.A. 16980 (1786:18–21). Therefore, that Maige’s current
threshold only increases during start-up mode—not
normal operation—is irrelevant to the analysis. See
Unwired Planet, LLC v. Google Inc., --- F.3d ---, 2016 WL
6694955, at *5 (Fed. Cir. Nov. 15, 2016) (“[C]ombinations
of prior art that sometimes meet the claim elements are
sufficient to show obviousness.”); see also Hewlett-Packard
Co. v. Mustek Sys., Inc., 340 F.3d 1314, 1326 (Fed. Cir.
2003) (“Just as ‘an accused product that sometimes, but
not always, embodies a claimed method nonetheless
infringes,’ a prior art product that sometimes, but not
always, embodies a claimed method nonetheless teaches
that aspect of the invention.” (quoting Bell Commc’ns
Research, Inc. v. Vitalink Commc’ns Corp., 55 F.3d 615,
622–623 (Fed. Cir. 1995)).
    Equally irrelevant is the oscilloscope screen capture
presented at trial by Dr. Kelley:
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          35




Appellee’s Opening Br. 57. The screen capture purports
to show that the current threshold (shown in dark blue)
remains constant during the power supply’s on time
(represented by the two higher portions of the light-blue
waveform). But the screen capture is limited to a
100 µsec 18 window of operation. It is not surprising that
the current threshold did not measurably increase during
this time. By Dr. Kelley’s own admission, the current
threshold increases over the full one-second start-up
period. See J.A. 16980 (1787:20–25). As such, the current
threshold would increase only 1/10,000th of its full range
over the course of the entire screen capture. It is not
surprising that such a small increase is not visible to the
human eye considering the 2-volt-per-division scaling
used in the screen capture.
    All that matters for anticipation is that Maige disclose
“a variable current limit threshold that increases during
the on time of the switch.” Power Integrations’ expert,
Dr. Kelley, admitted that it does. The jury therefore


   18  1 µsec (also known as 1 microsecond) is 0.000001
seconds. 100 µsec is equal to 0.0001 seconds.
36        POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



lacked substantial evidence to find that Maige did not
anticipate claims 1 and 2 of the ’605 patent.
       III. The ’972 Patent (Primary-Side Control)
     The jury found that claims 6, 7, 18, and 19 were not
invalid. It further found that Power Integrations in-
fringed the claims under the doctrine of equivalents, but
did not infringe literally and did not induce others to
infringe. Fairchild appeals the jury’s verdict that Power
Integrations did not induce infringement of the asserted
claims. Power Integrations cross-appeals and raises the
following arguments: (1) the district court improperly
construed the claim limitation “sampling a voltage from
the auxiliary winding of the transformer and a discharge
time of the transformer;” (2) the jury’s verdict that the
claims would not have been obvious in view of Majid in
combination with the ’876 patent is not supported by
substantial evidence; and (3) the jury’s verdicts that
Power Integrations did not literally infringe the claims
but did infringe under the doctrine of equivalents result
in claim vitiation.
    We affirm the district court’s claim construction and
the jury’s verdict that claims 6, 7, 18, and 19 would not
have been obvious. We agree with Power Integrations
that the jury’s infringement verdicts vitiate the require-
ment that the claimed feedback signals be “distinct.” We
therefore reverse the jury’s verdict that Power Integra-
tions infringed claims 6, 7, 18, and 19 under the doctrine
of equivalents. In view of these decisions, Fairchild’s
appeal is moot.
                 A. Claim Construction
    The ’972 patent claims a power supply that includes
frequency jittering and primary-side feedback to prevent
overcurrent. ’972 patent, 1:9–12. Fairchild asserted
claims 6, 7, 18, and 19 of the patent against Power Inte-
grations. Claim 6 depends from claim 1. Claim 1 reads
as follows:
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR         37



   1. A power converter comprising:
        a switch, responsive to a switching signal,
        to control electrical power in the power
        converter; and
        a controller to generate the switching sig-
        nal and to control the switching signal in
        response to a first feedback signal associ-
        ated with a voltage control loop and a sec-
        ond feedback signal associated with a
        current control loop;
        wherein the controller includes a pattern
        generator to generate a digital pattern
        and the controller uses the digital pattern
        for use in generating the switching signal
        as a frequency-hopping switching signal to
        the switch.
Id. at 15:22–49. Claim 6 19 further requires “wherein the
controller generates the first feedback signal by sampling
a voltage from the auxiliary winding of the transformer
and a discharge time of the transformer.” Id. at 15:50–53
(emphasis added). Claim 7 depends from claim 6 and
further limits independent claim 1’s “second feedback
signal.” It is not relevant to the parties’ claim construc-
tion dispute. Claims 18 and 19 depend from claim 15 and
are analogous to claims 6 and 7, but in method form.
    The parties dispute the construction of the limitation
“sampling a voltage from the auxiliary winding of the
transformer and a discharge time of the transformer.”
The district court adopted Fairchild’s proposed construc-
tion: “sampling a voltage from the auxiliary winding of
the transformer when the transformer is discharging.”


   19  Claim 6 depends from claim 1 by way of claims 2
and 5. None of the limitations added in claims 2 or 5 are
relevant to this issue.
38        POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



Claim Construction Order, 2009 WL 4928029, at *25.
Power Integrations contends that the district court’s
construction departs from the plain and ordinary meaning
of the claims, which it claims requires sampling both a
voltage and a discharge time.
     “[T]he words of a claim ‘are generally given their or-
dinary and customary meaning.’” Phillips v. AWH Corp.,
415 F.3d 1303, 1312 (Fed. Cir. 2005) (en banc) (quoting
Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582
(Fed. Cir. 1996)). The “ordinary and customary meaning”
is “the meaning that the term would have to a person of
ordinary skill in the art in question at the time of the
invention.” Id. at 1313. “Properly viewed, the ‘ordinary
meaning’ of a claim term is its meaning to the ordinary
artisan after reading the entire patent.” Id. at 1321.
     We disagree with Power Integrations that the limita-
tion at issue is clear on its face. See Appellee’s Opening
Br. 25 (“The claims’ ordinary meaning could not be clear-
er.”). Specifically, it is ambiguous what clauses are linked
by the conjunction “and.” The limitation could be con-
strued to require that the controller sample (1) “a voltage
from the auxiliary winding of the transformer,” and (2) “a
discharge time of the transformer,” as Power Integrations
argues. Alternatively, the limitation could be construed
to require that the controller sample a voltage from
(1) “the auxiliary winding of the transformer,” and (2) “a
discharge time of the transformer.” In this alternative
construction, the limitation defines both where the volt-
age is sampled (i.e., the auxiliary winding of the trans-
former) and when the voltage is sampled (i.e., during the
discharge time of the transformer). The district court
adopted this latter construction.
    While the limitation is ambiguous in isolation, we find
its meaning clear when viewed in the context of the
patent specification. Phillips, 415 F.3d at 1313 (“Im-
portantly, the person of ordinary skill in the art is deemed
to read the claim term not only in the context of the
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR           39



particular claim in which the disputed term appears, but
in the context of the entire patent, including the specifica-
tion.”).
     The specification explains that, when the power sup-
ply’s switch is turned off, electrical energy stored in the
power supply’s transformer flows from the primary side of
the transformer to the secondary, or auxiliary, side of the
transformer. ’972 patent, 3:36–42. It is during this
“discharge time” that voltage is generated at the auxiliary
winding of the transformer. Id. at 3:56–58. The specifica-
tion later explains that the power supply’s controller
samples this voltage (VAUX) during the discharge time.
See id. at 7:48–51; id. at 8:49–9:30. The power supply
uses the sampled voltage as a mechanism to generate the
first feedback signal. See id. at 4:29–42 (describing how
VAUX is used to generate detector voltage VDET); id. at 5:1–
16 (describing how VDET is used to generate feedback VV).
The patent specification’s description is thus consistent
with the district court’s construction that “sampling a
voltage from the auxiliary winding of the transformer and
a discharge time of the transformer” means “sampling a
voltage from the auxiliary winding of the transformer
when the transformer is discharging.”
    Power Integrations’ argument that the district court’s
construction “create[s] problems for the analogous lan-
guage in unasserted claims 8 and 20” does not change this
result. Appellee’s Opening Br. 27. Claims 8 and 20
depend from asserted claims 7 and 19, respectively, and
require “generating the second feedback signal by sam-
pling of sensed current and the discharge time of the
transformer.” ’972 patent 16:58–61; see also id. at 15:58–
61 (“generat[ing] the second feedback signal by sampling
of the sensed current from the sense circuit and the
discharge time of the transformer”). Power Integrations
contends that replacing “and” with “when”—its character-
ization of the district court’s construction of claims 6 and
18—would require that the sensed current be sampled
40         POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



from the sensed circuit when the transformer is discharg-
ing, an impossibility because the sensed current does not
exist when the transformer is discharging. Appellee’s
Opening Br. 27–28.
    Power Integrations’ argument is based on a faulty
premise. The district court was not asked to construe the
word “and” in claims 6 and 18. And, it did not do so.
Rather, it construed the entire claim term “sampling a
voltage from the auxiliary winding of the transformer and
a discharge time of the transformer.” One cannot assume
that an individual portion of the district court’s construc-
tion can be imported into claims 8 and 20 simply because
those claims use similar language. Similar language in
different claims may be construed differently based on the
context in which it is used and other intrinsic evidence.
See Wilson Sporting Goods Co. v. Hillerich & Bradsby Co.,
442 F.3d 1322, 1328 (Fed. Cir. 2006) (“Under this court’s
case law, the same terms appearing in different claims in
the same patent—e.g. ‘gap’ in claims 1 and 15—should
have the same meaning ‘unless it is clear from the specifi-
cation and prosecution history that the terms have differ-
ent meanings at different portions of the claims.’ In this
case, the claims use the term ‘gap,’ but then modify it
differently to suggest differences in the geometry of the
‘gap’ in the various claims.” (citation omitted)).
     We therefore affirm the district court’s construction.
                         B. Validity
    Power Integrations argues that claims 6, 7, 18, and 19
of the ’972 patent would have been obvious in view of
Majid and the ’876 patent. The jury rejected this argu-
ment at trial. We affirm the jury’s verdict.
   Majid describes a switched-mode power supply that
uses feedback to control output voltage, thereby prevent-
ing damage to downstream components. See Majid,
Abstract. The ’876 patent—described above, supra at 7–
8—claims a circuit that introduces “jitter” to a power
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR           41



supply’s oscillator frequency to reduce the amount of EMI
generated by the power supply. ’876 patent, 1:66–67.
Power Integrations contends a combination of these two
references discloses every limitation of claims 6, 7, 18,
and 19 of the ’972 patent. It further contends that com-
bining the features disclosed in the references would have
been easy for one of ordinary skill in the art, thereby
rendering the claims obvious. Fairchild counters that the
asserted claims would not have been obvious for two
reasons. First, it argues that Majid does not disclose the
specific second feedback signal claimed in the ’972 patent.
Second, it argues that one of ordinary skill in the art
would have experienced great difficulty in combining
Majid with the ’876 patent.
     At trial, the parties supported their arguments with
the testimony of their respective experts, Dr. Kelley for
Power Integrations and Dr. Wei for Fairchild. Each
expert testified in rather conclusory fashion. With little
explanation, Dr. Kelley highlighted the portions of Majid
and the ’876 patent that he believed disclosed the differ-
ent claim limitations. J.A. 17048 (2171:14–2174:19). The
focus of his testimony was whether it would have been
difficult for a skilled artisan to combine frequency jitter
(i.e., the ’876 patent) with primary-side control (i.e.,
Majid); he concluded that it would not have been.
J.A. 17048–49 (2174:20–2178:8). Dr. Wei, likewise with
little explanation, testified that Majid did not disclose the
“second feedback signal” claimed in the ’972 patent and
that it would have been difficult to combine frequency
jitter with primary-side control. J.A. 17057–58 (2208:3–
2211:20).
    Each expert’s credibility was called into question dur-
ing cross-examination. Counsel for Fairchild raised an
apparent inconsistency between Dr. Kelley’s expert report
on non-infringement and his testimony on invalidity. In
opining that Power Integrations did not infringe the ’972
patent, Dr. Kelley stated that the current output of a
42        POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



conventional current limit circuit—like that supposedly
employed by Power Integrations—did not satisfy the
“second feedback signal” required by the claims.
J.A. 17055–56 (2200:12–2203:8). Yet, in testifying that
the claims would have been obvious, Dr. Kelley testified
that Majid’s conventional current limit circuit did satisfy
the “second feedback signal” limitation of the claims.
J.A. 17055 (2200:3–11).
    Counsel for Power Integrations similarly exposed an
apparent inconsistency between Dr. Wei’s trial testimony
and his testimony during deposition. At trial, Dr. Wei
testified that Majid did not disclose the “second feedback
signal” limitation. J.A. 17057 (2208:24–2209:7). But,
during deposition, Dr. Wei testified that the combination
of Majid and the ’876 patent disclosed all claim limita-
tions. J.A. 17061–62 (2226:19–2227:9).
    “When reviewing a denial of judgment as a matter of
law of obviousness, where there is a black box jury ver-
dict, as is the case here, we presume the jury resolved
underlying factual disputes in favor of the verdict winner
and leave those presumed findings undisturbed if sup-
ported by substantial evidence.” WBIP, LLC v. Kohler
Co., 829 F.3d 1317, 1326 (Fed. Cir. 2016). Dr. Wei’s
testimony provided the jury with substantial evidence for
its presumed findings that Majid did not disclose the
“second feedback signal” limitation of claims 6, 7, 18, and
19 and that a skilled artisan would have had difficulty
combining frequency jitter with primary-side control.
While Dr. Kelley testified to the contrary, “when there is
conflicting testimony at trial, and the evidence overall
does not make only one finding on the point reasonable,
the jury is permitted to make credibility determinations
and believe the witness it considers more trustworthy.”
MobileMedia Ideas LLC v. Apple Inc., 780 F.3d 1159, 1168
(Fed. Cir. 2015) (citation omitted). “Where there is sub-
stantial evidence for a reasonable jury finding, it is not
our function to second guess or reevaluate the weight
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          43



given to that evidence.” Id. This is particularly true here,
where it was Power Integrations’ burden to prove by clear
and convincing evidence that the claims were invalid.
    We therefore find the jury’s verdict that claims 6, 7,
18, and 19 would not have been obvious in view of Majid
and the ’876 patent supported by substantial evidence.
               C. Doctrine of Equivalents
    Claims 6 and 7 of the ’972 patent depend from claim
1, which includes the following limitation:
    a controller to generate the switching signal and
    to control the switching signal in response to a
    first feedback signal associated with a voltage
    control loop and a second feedback signal associ-
    ated with a current control loop . . . .
’972 patent, 15:25–29. Claims 18 and 19 depend from
claim 15, which includes an equivalent limitation. Id. at
16:36–40. The district court construed this limitation to
require that the claimed second feedback signal be “dis-
tinct from the first feedback signal.” Claim Construction
Order, 2009 WL 4928029, at *12. Neither party appeals
this construction.
    The patent’s Figure 3 graphically depicts the claimed
voltage control loop and current control loop and their
respective first and second feedback signals.
46        POWER INTEGRATIONS    v. FAIRCHILD SEMICONDUCTOR



claimed two “distinct” feedback signals would vitiate the
“distinct”-ness required by the claims. Pursuant to this
understanding, Power Integrations argues that it is
entitled to JMOL of no infringement.
    In response, Fairchild first argues that Power Inte-
grations’ invocation of claim vitiation is misplaced. It
states that Power Integrations presented two, separate
non-infringement theories at trial: first, that the two
feedback signals Fairchild’s expert, Dr. Wei, identified
were not “distinct;” and second, that the current signal
Dr. Wei identified as the claimed “second feedback signal”
was not actually a “feedback signal.” It contends that
only Power Integrations’ first theory could conceivably
result in claim vitiation and argues that we should not
assume the jury relied on this theory when it could have,
just as easily, relied on Power Integrations’ alternate
theory. The district court adopted Fairchild’s reasoning
in denying Power Integrations’ motion for JMOL of no
infringement under the doctrine of equivalents. JMOL
Decision, 935 F. Supp. 2d at 754.
    We disagree with Fairchild and the district court.
Power Integrations’ expert, Dr. Kelley, presented a single
non-infringement theory at trial, namely, that Power
Integrations’ products include only a single feedback
signal. See, e.g., J.A. 17041 (2145:11–14) (Dr. Kelley: “It
uses just a single feedback signal that arrives at one pin
that is indicative of the output voltage, and that is used to
regulate the output voltage, but it does not have any kind
of current feedback signal.”); J.A. 17043 (2151:23–2152:2)
(Dr. Kelley testifying that the LinkSwitch-II does not
have two feedback signals). When Dr. Kelley testified
that the output of the LinkSwitch-II’s constant current
block (i.e., “I REDUCE”) was not a “feedback signal,” he
did not introduce a new non-infringement theory. Rather,
he made clear that the output was not a “feedback signal”
because the LinkSwitch-II used only a single feedback
signal (i.e., “FEEDBACK (FB)”):
POWER INTEGRATIONS    v. FAIRCHILD SEMICONDUCTOR         47



   Q. Okay. Focusing on the constant current block,
   is the output of the constant current block a sec-
   ond feedback signal associated with a current con-
   trol loop?
   A. No, it’s not.
   Q. Why not?
   A. There’s no current input, the constant current
   block. All it has as an input is the same voltage
   feedback signal that’s used elsewhere.
J.A. 17043 (2152:18–25) (emphasis added). As such, the
jury necessarily found that the LinkSwitch-II products
contain a single feedback signal when it rendered its
verdict of no literal infringement.
    We must therefore weigh the merits of Power Integra-
tions’ claim vitiation argument. Under claim vitiation, “if
a court determines that a finding of infringement under
the doctrine of equivalents would entirely vitiate a partic-
ular claimed element, then the court should rule that
there is no infringement under the doctrine of equiva-
lents.” Lockheed Martin Corp. v. Space Systems/Loral,
Inc., 324 F.3d 1308, 1321 (Fed. Cir. 2003) (internal quota-
tion marks, alternations, and citation omitted); see also
Warner-Jenkinson Co., Inc. v. Hilton Davis Chem. Co.,
520 U.S. 17, 40 (1997) (“[I]f a theory of equivalence would
entirely vitiate a particular claim element, partial or
complete judgment should be rendered by the court.”).
    We agree with Power Integrations that a finding of in-
fringement under the doctrine of equivalents would
vitiate the requirement that the claimed feedback signals
be “distinct.” The inventor of the ’972 patent detailed at
trial the difficulty he and his team had in designing a
power supply with accurate primary-side control and the
breakthrough he achieved by adding a second feedback
signal specifically related to output current. J.A. 16917
(1822:8–1824:24). He went on to testify that having a
48        POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR



second feedback signal—related to current—that is dis-
tinct from the first feedback signal—related to voltage—is
what distinguished the claimed invention from the prior
art. J.A. 16924 (1851:15–1852:11).
     Here, the jury implicitly found that Power Integra-
tions’ LinkSwitch-II products contain a single feedback
signal, not two “distinct” feedback signals as required by
the claims. “[N]ot using two distinct signals to control
voltage and current can’t be equivalent to using distinct
signals—the signals are either distinct or they aren’t.”
Appellee’s Opening Br. 29. A finding to the contrary
would render the requirement that the feedback signals
be “distinct”—the feature described by the inventor as
critical to the invention’s novelty—meaningless. See Am.
Calcar, Inc. v. Am. Honda Motor Co., 651 F.3d 1318, 1339
(Fed. Cir. 2011) (rejecting plaintiff’s doctrine of equiva-
lents theory and reasoning that “finding a signal from one
source to be equivalent to ‘signals from a plurality of
sources’ would vitiate that claim limitation by rendering
it meaningless”).
    We therefore reverse the jury’s verdict that Power In-
tegrations infringed claims 6, 7, 18, and 19 under the
doctrine of equivalents.
                IV. Permanent Injunction
    Following trial, the district court granted Power Inte-
grations’ motion for a permanent injunction and enjoined
“Fairchild from selling, offering to sell, and importing the
products found at trial to infringe and those products ‘not
colorably different’ from them.” Permanent Injunction
Order, 2014 WL 2960035, at *2. The district court denied
Fairchild’s motion for a permanent injunction. Fairchild
appeals both of these rulings.
    We first note that Fairchild’s appeal of the district
court’s denial of Fairchild’s motion for a permanent
injunction is moot. The district court entered judgment of
infringement against Power Integrations on the ’972
POWER INTEGRATIONS   v. FAIRCHILD SEMICONDUCTOR          49



patent alone. We have reversed that judgment. See
supra at 43–48. Without a judgment of infringement by
Power Integrations, issuance of a permanent injunction is
not appropriate.
    Turning to the district court’s grant of Power Integra-
tions’ motion for a permanent injunction, we vacate that
decision. We have significantly reduced the scope of
Fairchild’s infringement liability in this case. As a result
of our above holdings, only the district court’s judgment
that Fairchild is liable for direct infringement of the ’851
and ’876 patents remains untouched. We leave it to the
district court to determine in the first instance if a per-
manent injunction is appropriate in view of Fairchild’s
infringement liability. Though, we recognize that the
district court may exercise its discretion and defer its
decision until Power Integrations’ claims that Fairchild
induced infringement of the ’851 and ’876 patent are
resolved.
                       CONCLUSION
    For the preceding reasons, we affirm-in-part, reverse-
in-part, and vacate-in-part the final judgment entered by
the district court and remand for further proceedings.
    AFFIRMED-IN-PART, REVERSED-IN-PART,
      VACATED-IN-PART, AND REMANDED
                          COSTS
   Each party shall bear its own costs.
