United States Court of Appeals 

for the Federal Circuit ______________________ 

 

POWER INTEGRATIONS, INC.,

Plaintiff-Appellant

v.

MICHELLE K. LEE, DIRECTOR, U.S. PATENT AND 

TRADEMARK OFFICE,

Defendant-Appellee

______________________ 

2014-1123

______________________ 

Appeal from the United States District Court for the 

District of Columbia in No. 1:11-cv-01254-BJR, Judge 

Barbara Jacobs Rothstein.

______________________ 

Decided: August 12, 2015 

______________________ 

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

San Diego, CA; FRANK SCHERKENBACH, Boston, MA.

AMY J. NELSON, Office of the Solicitor, United States 

Patent and Trademark Office, Alexandria, VA, argued for 

defendant-appellee. Also represented by NATHAN K.

KELLEY, SCOTT WEIDENFELLER. 

______________________ 

Before MOORE, MAYER, and LINN, Circuit Judges.
2 POWER INTEGRATIONS, INC. v. LEE

MAYER, Circuit Judge.

Power Integrations, Inc. (“Power Integrations”) challenges a decision of the Board of Patent Appeals and 

Interferences (“board”) affirming the rejection of claims 1, 

17, 18, and 19 of U.S. Patent No. 6,249,876 (the “’876 

patent”) as anticipated under 35 U.S.C. § 102(b). See Ex 

parte Power Integrations, Inc., No. 2010-011021, 2010 WL 

5244756 (B.P.A.I. Dec. 22, 2010) (“Power Integrations 

III”). For the reasons discussed below, we vacate and 

remand.

BACKGROUND

The ’876 patent is entitled “Frequency Jittering Control for Varying the Switching Frequency of a Power 

Supply.” It is directed to a technique for reducing electromagnetic interference by jittering the switching frequency of a switched mode power supply. See ’876 patent 

col.1 ll.66–67. Claim 1, as amended, recites:

A digital frequency jittering circuit for varying the 

switching frequency of a power supply, comprising:

an oscillator for generating a signal having 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 oscillator, 

the digital to analog converter coupled to the 

counter, the counter causing the digital to analog 

converter to adjust the control input and to vary 

the switching frequency of the power supply.

J.A. 710.

Claims 17, 18, and 19 relate to a method for varying 

the switching frequency using a varying voltage to control 
POWER INTEGRATIONS, INC. v. LEE 3

the oscillator. ’876 Patent col.9 ll.37–52. Independent 

claim 17, as amended, requires “cycling a counter” to 

generate a secondary voltage that varies over time:

A method for generating a switching frequency in 

a power conversion system, comprising:

generating a primary voltage;

cycling a counter coupled to one or more secondary voltage sources to generate a secondary voltage which varies over time; and

combining the secondary voltage with the primary 

voltage to be received at a control input of a voltage-controlled oscillator for generating the switching frequency of the power conversion system 

which is varied over time.

J.A. 713.

In 2004, Power Integrations brought suit against 

Fairchild Semiconductor International, Inc. and related 

parties (collectively “Fairchild”) in the United States 

District Court for the District of Delaware. It alleged that 

Fairchild had willfully infringed the ’876 patent, as well 

as United States Patent Nos. 4,811,075, 6,107,851, and 

6,229,366. See Power Integrations, Inc. v. Fairchild 

Semiconductor Int’l, Inc., 422 F. Supp. 2d 446, 448 (D. 

Del. 2006), aff’d in part, rev’d in part, 711 F.3d 1348 (Fed. 

Cir. 2013) (“Power Integrations I”). During claim construction proceedings, Power Integrations argued that the 

term “coupled” in claim 1 of the ’876 patent, when read in 

light of the specification and surrounding claim language, 

required that two circuits be connected in a manner “such 

that voltage, current, or control signals pass from one to 

another.” Id. at 455. It further contended that the “recited coupling” between the counter and the digital to analog 

converter must be “present for the purposes of control.” 

Id. (citations and internal quotation marks omitted). 

Power Integrations made clear, however, that its pro-
4 POWER INTEGRATIONS, INC. v. LEE

posed construction did not require a direct connection 

between circuit elements. Id. The district court adopted 

Power Integrations’ proposed claim construction, concluding that it was “consistent with the claim language and 

the context of the specification which describes the purpose for which various parts of the claimed invention are 

coupled.” Id. at 456. The court emphasized, moreover, 

that its construction of the term “coupled” did not “require 

a direct connection or . . . preclude the use of intermediate 

circuit elements.” Id. In the wake of the trial court’s 

claim construction, Fairchild withdrew its anticipation 

defense, instead arguing at trial that U.S. Patent No. 

4,638,417 (“Martin”) rendered claim 1 obvious. 

In 2006, the trial court bifurcated the litigation, 

separating issues of infringement and damages from 

issues related to patent validity. A first jury found that 

Fairchild had willfully infringed claim 1 of the ’876 patent, as well as several claims of the other asserted patents. After a trial on validity, a second jury returned a 

verdict that claim 1 of the ’876 patent was not obvious in 

view of Martin. 

On appeal, this court affirmed the jury’s finding that 

claim 1 of the ’876 patent was not invalid for obviousness. 

See Power Integrations, Inc. v. Fairchild Semiconductor 

Int’l, Inc., 711 F.3d 1348, 1366–69 (Fed. Cir. 2013) (“Power Integrations II”). We noted that the “salient difference” 

between the ’876 patent and Martin is Martin’s inclusion 

of an erasable programmable read only memory 

(“EPROM”). Id. at 1366. We explained that Martin

always includes an EPROM between the counter and the 

digital to analog converter and “does not teach removing 

the EPROM . . . as in the ’876 Patent.” Id. at 1367. We 

concluded, moreover, that “substantial evidence of objective considerations of non-obviousness [supported] the 

jury’s conclusion that claim 1 of Power Integrations’ ’876 

Patent would not have been obvious to the ordinarily 

skilled artisan.” Id. at 1369.
POWER INTEGRATIONS, INC. v. LEE 5

In December 2006, while district court proceedings 

were pending, the United States Patent and Trademark 

Office granted Fairchild’s request for ex parte reexamination of claims 1, 17, 18, and 19 of the ’876 patent. J.A. 

165–73. The board affirmed the examiner’s rejection of 

claim 1 as anticipated by Martin, as well as by two additional references: (1) Thomas G. Habetler & Deepakraj 

M. Divan, Acoustic Noise Reduction in Sinusoidal PWM

Drives Using a Randomly Modulated Carrier, 6 IEEE

TRANSACTIONS ON POWER ELECS. 356–63 (1991)

(“Habetler”); and (2) Andrew C. Wang & Seth R. Sanders,

Programmed Pulsewidth Modulated Waveforms for

Electromagnetic Interference Mitigation in DC-DC Converters, 8 IEEE TRANSACTIONS ON POWER ELECS. 596–

605 (1993) (“Wang”). The board stated that Power Integrations “appear[ed] to argue that one of ordinary skill in 

the art would understand the term ‘coupled to’ to restrict 

device connections to exclude intervening components.” 

Power Integrations III, 2010 WL 5244756, at *4. The 

board concluded, however, that the term meant simply to 

“join[] devices into a single circuit,” and did not preclude 

the presence of intervening components. Id. In addition, 

the board rejected Power Integrations’ argument “that the 

respective counters in Martin, Wang, and Habetler are 

not coupled to the respective digital to analog converters 

because all [Martin, Wang, and Habetler] disclose a [read 

only memory (“ROM”)] separating a counter from a digital 

to analog converter.” Id. (citations and internal quotation 

marks omitted). In the board’s view, Martin, Wang, and 

Habetler disclosed the limitations of claim 1 because they 

joined a counter and a digital to analog converter in a 

single circuit, and the counter “produce[d] a signal that 

causes a digital to analog converter to adjust control input 

by utilizing a corresponding memory, the counter (with 

the corresponding memory) being ‘coupled to’ the digital 

to analog converter.” Id.
6 POWER INTEGRATIONS, INC. v. LEE

The board also affirmed the examiner’s rejection of 

claims 17, 18, and 19 as anticipated by Habetler. In light 

of its construction of the term “coupled to” in claim 1, the 

board rejected Power Integrations’ argument that 

Habetler did not anticipate claims 17, 18, and 19 because 

it contains an EPROM between the counter and the 

digital to analog converter. Id. at *5. The board likewise 

rejected Power Integrations’ argument that Habetler fails 

to disclose primary and secondary voltage sources. Id. at 

*6. According to the board, both the output from the 

digital to analog converter and the “average slope” of 

Habetler are voltage signals. Id. The board asserted that 

“Habetler discloses that [pulse width modulator (“PWM”)] 

schemes utilize discrete tones in the voltage spectrum and 

that the output from PWM circuitry are waveforms with 

voltage amplitudes . . . thus confirming that the PWM 

circuitry processes voltage waveforms to obtain output 

voltage waveforms.” Id. (citations and internal quotation 

marks omitted).

In February 2011, Power Integrations filed a request 

for rehearing with the board pursuant to 37 

C.F.R. § 41.52. It argued that the board had “misapprehended” its argument regarding the proper construction 

of the term “coupled to” in claim 1 of the ’876 patent, 

explaining that it had never contended that the term 

precluded the presence of intermediate circuit elements 

between the counter and the digital to analog converter. 

J.A. 935. Power Integrations further asserted that the 

board erred in finding that claims 17, 18, and 19 were 

anticipated by Habetler because that reference did not 

“disclose, teach or fairly suggest that the output of the 

[digital to analog] converter of FIG. 5 is a voltage, that the 

‘average slope’ signal of FIG. 5 is a voltage, or that the 

input of the Triangle Generator of FIG. 5 is a voltage.” 

J.A. 952. Power Integrations argued, moreover, that the 

board had improperly shifted the burden of proof by 
POWER INTEGRATIONS, INC. v. LEE 7

applying a presumption that Habetler’s average slope

was a voltage. J.A. 951.

In May 2011, the board denied Power Integrations’ 

request for rehearing. See Ex parte Power Integrations, 

Inc., No. 2010-011021, 2011 WL 1821718 (B.P.A.I. May 

10, 2011) (“Power Integrations IV”). It rejected the contention that it had misapprehended Power Integrations’ 

argument about the proper construction of the term 

“coupled.” Id. at *1. The board stated that “even assuming that [Power Integrations’] contention that elements 

are ‘coupled’ with the presence of ‘intervening components’ is true, and further assuming that [Power Integrations’] assertion that Habetler discloses an intervening 

element (i.e., an EPROM) between a counter and a converter is also true, it follows that Habetler would disclose 

a counter ‘coupled to’ a converter under [Power Integrations’] proposed analysis.” Id. As to claims 17, 18, and 

19, the board withdrew any statements implying that it 

had shifted the burden to Power Integrations to prove 

that Habetler’s average slope was not a voltage source. 

Id. at *2. The board reiterated, however, its previous 

conclusion that Habetler discloses output data that are 

voltage waveforms with voltage amplitudes. Id. at *2–3.

Power Integrations then filed suit in the United 

States District Court for the District of Columbia challenging the board’s decision. See Power Integrations, Inc. 

v. Kappos, 6 F. Supp. 3d 11 (D.D.C. 2013) (“Power Integrations V”). After correctly determining that it lacked 

subject matter jurisdiction, see In re Teles AG Informationstechnologien, 747 F.3d 1357, 1364–66 (Fed. Cir. 

2014), the district court transferred the case to this court 

pursuant to 28 U.S.C. § 1631, see Power Integrations V, 6 

F. Supp. 3d at 24. We have jurisdiction under 28 U.S.C. 

§ 1295(a)(4)(A).
8 POWER INTEGRATIONS, INC. v. LEE

DISCUSSION

A. Standard of Review

We review the legal conclusions of the board de novo. 

In re Elsner, 381 F.3d 1125, 1127 (Fed. Cir. 2004). In an 

appeal from the board, anticipation is a question of fact 

which we review for substantial evidence. In re Antor 

Media Corp., 689 F.3d 1282, 1287 (Fed. Cir. 2012); In re 

Gleave, 560 F.3d 1331, 1334–35 (Fed. Cir. 2009). In 

assessing whether a claim is anticipated under 35 U.S.C. 

§ 102, “[a] single prior art reference that discloses, either 

expressly or inherently, each limitation of a claim invalidates that claim by anticipation.” Perricone v. Medicis 

Pharm. Corp., 432 F.3d 1368, 1375 (Fed. Cir. 2005).

B. The Board’s Anticipation Rejections

Proceedings of the board are governed by the Administrative Procedure Act (“APA”), 5 U.S.C. §§ 702, 704, 

which “establishes a scheme of reasoned decisionmaking,” 

Allentown Mack Sales & Serv., Inc. v. NLRB, 522 U.S. 

359, 374 (1998) (citations and internal quotation marks 

omitted); see Dickinson v. Zurko, 527 U.S. 150, 154–65

(1999). Under the APA, the board is obligated not only to 

come to a sound decision, but to fully and particularly set 

out the bases upon which it reached that decision. In re 

Sang-Su Lee, 277 F.3d 1338, 1342 (Fed. Cir. 2002); see

Gechter v. Davidson, 116 F.3d 1454, 1457 (Fed. Cir. 1997). 

To permit effective appellate review, the board’s patentability analyses must be both “clearly disclosed and adequately sustained.” Sec. & Exch. Comm’n v. Chenery 

Corp., 318 U.S. 80, 94 (1943); see In re Thrift, 298 F.3d 

1357, 1364 (Fed. Cir. 2002) (emphasizing that the board is 

required to “document its reasoning on the record to allow 

accountability” and to facilitate “effective judicial review”); Gechter, 116 F.3d at 1457 (explaining that the 

board’s reasoning must be set out with sufficient specificity to enable this court, “without resort to speculation,” to 

effectively evaluate an anticipation rejection); Mullins v. 
POWER INTEGRATIONS, INC. v. LEE 9

Dep’t of Energy, 50 F.3d 990, 992 (Fed. Cir. 1995) (“It is 

well established that agencies have a duty to provide 

reviewing courts with a sufficient explanation for their 

decisions so that those decisions may be judged against 

the relevant statutory standards, and that failure to 

provide such an explanation is grounds for striking down 

the action.”).

Here, however, the board fundamentally misconstrued Power Integrations’ principal claim construction 

argument and failed to provide a full and reasoned explanation of its decision to reject claim 1 of the ’876 patent as 

anticipated. Before this court, the district court, and the 

board, Power Integrations has consistently argued that 

claim 1, when read in light of the specification and surrounding claim language, requires that the counter itself—not a pre-programmed memory—controls the digital 

to analog converter’s output to vary the switching frequency.1 Br. of Plaintiff-Appellant 9, 18–20; Power Integrations I, 422 F. Supp. 2d at 455; J.A. 817–19, 876–77, 

896–98. In its view, the “coupled” limitation in claim 1 

requires that the counter be connected to the digital to 

analog converter in a manner that allows it to pass voltage, current, or control signals to instruct the digital to 

analog converter. See Power Integrations I, 422 F. Supp. 

2d at 455 (“Power Integrations contends that two circuits 

are coupled when they are connected such that voltage, 

current, or control signals pass from one to another,” with 

“the recited coupling . . . present for the purposes of 

control” (citations and internal quotation marks omitted)); 

J.A. 896 (“[Power Integrations] respectfully submits that 

1 In Habetler, Wang, and Martin, the prior art references cited by the board, a memory (either a ROM or an 

EPROM) separates the digital to analog converter and the 

counter. See Power Integrations III, 2010 WL 5244756, at 

*3–5. 

 
10 POWER INTEGRATIONS, INC. v. LEE

the proper claim interpretation by one skilled in the art of 

the term ‘coupled to’ in the context of the surrounding 

claim language and the specification would result in two 

circuits being coupled when they are connected such that 

voltage, current or control signals pass from one to another for the purposes of control.”). Power Integrations has 

repeatedly made clear, however, that its proposed claim 

construction does not preclude the presence of intervening 

components between the counter and the digital to analog 

converter. See Power Integrations I, 422 F. Supp. 2d at 

455 (emphasizing that Power Integrations’ proposed

interpretation of the term “coupled” did not require a 

“direct connection” between the counter and the digital to 

analog converter); J.A. 897 (“[Power Integrations] wishes 

to clarify that [its] construction of the term ‘coupled’ 

should not be read to imply or necessitate a direct, physical connection, as . . . the specification [does not] require a 

direct connection or . . . preclude the use of intermediate 

circuit elements.”).

The district court adopted Power Integrations’ proposed construction of the term “coupled,” concluding that 

it was “consistent with the claim language and the context of the specification which describes the purpose for 

which various parts of the claimed invention are coupled.” 

Power Integrations I, 422 F. Supp. 2d at 456. During 

reexamination, however, the board failed to acknowledge 

the district court’s claim construction or to assess whether 

its interpretation of the term “coupled” was consistent 

with the broadest reasonable construction of the term. 

Instead, the board devoted a substantial portion of its 

analysis to resolving the question of whether the term 

“coupled” requires a direct connection between the counter and the digital to analog converter. Power Integrations III, 2010 WL 5244756, at *3–5. Relying on a 

generalist dictionary definition, the board concluded that 

no such direct connection is required because “the plain 
POWER INTEGRATIONS, INC. v. LEE 11

and customary meaning” of the term “couple” is simply to 

“join[] devices into a single circuit.” Id. at *4.

As noted above, however, when Power Integrations 

was before the board it repeatedly acknowledged that the 

term “coupled” does not preclude the presence of intervening components between the counter and the digital to 

analog converter. Thus, a significant portion of the 

board’s opinion is devoted to rejecting an argument that 

Power Integrations not only never made, but instead 

expressly disavowed. Because so much of the board’s 

analysis is focused on a red herring—the issue of whether 

there can be intervening components between the counter 

and the digital to analog converter—it failed to adequately evaluate Power Integrations’ primary argument, which 

is that the “coupled” limitation requires that the counter 

pass control signals, voltage, or current to the digital to 

analog converter to control it, and that the presence of a 

memory programmed with data specifying how to vary 

the switching frequency “uncouples” the counter and the 

digital to analog converter and severs the requisite control relationship between them.2 See J.A. 782–83; 814–17, 

2 When it petitioned the board for rehearing, Power 

Integrations argued that the board had “misapprehended 

or overlooked” its principal argument regarding the 

proper interpretation of the term “coupled.” J.A. 935. It 

pointed out that, contrary to the board’s assertions, it had 

never contended that claim 1 precluded the presence of 

intervening components between the counter and the 

digital to analog converter. J.A. 935. The board summarily rejected this argument, however, stating that even 

accepting Power Integrations’ “contention that elements

are ‘coupled’ with the presence of ‘intervening components’ . . . and further assuming that [Power Integrations’] assertion that Habetler discloses an intervening 

element (i.e., an EPROM) between a counter and a con-

 
12 POWER INTEGRATIONS, INC. v. LEE

828, 858. In short, the board failed to straightforwardly 

and thoroughly assess the critical issue of whether claim 

1, when viewed in light of the specification and the surrounding claim language, requires the counter itself—and 

not the counter and a memory functioning together—to 

drive the digital to analog converter to adjust the control 

input and to vary the switching frequency of the power 

supply.3 See J.A. 817–19, 823; see also ’876 patent col.1 

ll.62–63 (explaining that adding “extra components” to 

reduce electromagnetic interference is “undesirabl[e]” 

because it “increase[s] the size and weight of the power 

supply”). Because the board’s opinion provides us with an 

inadequate predicate upon which to evaluate its decision 

to reject claim 1 of the ’876 patent as anticipated, we 

vacate and remand. See Sec. & Exch. Comm’n v. Chenery 

Corp., 332 U.S. 194, 196–97 (1947) (“It will not do for a 

court to be compelled to guess at the theory underlying 

the agency’s action.”); Thrift, 298 F.3d at 1366 (vacating a 

verter is also true, it follows that Habetler would disclose 

a counter ‘coupled to’ a converter under [Power Integrations’] proposed analysis.” Power Integrations IV, 2011 

WL 1821718, at *2. 3 Before the board, Power Integrations argued that 

in the prior art the counter itself does not send any signals to the digital to analog converter. J.A. 818–29. 

Instead, the counter’s signals are sent to the memory. 

Thus, in Power Integrations’ view, in prior art systems 

the digital to analog converter is “coupled to” receive the 

output of the memory, not the output of the counter. J.A. 

352, 358. The board, however, failed to adequately address whether the counter can be deemed “coupled to” the 

digital to analog converter to “caus[e]” it to adjust the 

control input and to vary the switching frequency of the 

power supply, ’876 Patent col.8 ll.51–53, even if the counter does not directly—or even primarily—control the 

digital to analog converter’s output.

 
POWER INTEGRATIONS, INC. v. LEE 13

board decision because it “failed to provide an adequate 

ground” for rejecting a claim); see also Walls v. United 

States, 582 F.3d 1358, 1368 (Fed. Cir. 2009) (remanding a 

personnel decision to the military board and requiring it 

to act on a completed record). 

Relying in part upon its construction of the term “coupled” in claim 1, the board determined that claims 17, 18, 

and 19 were anticipated by Habetler. See Power Integrations III, 2010 WL 5244756, at *5. Because we vacate the 

board’s construction of the “coupled” limitation in claim 1, 

we likewise vacate and remand its anticipation rejections 

of claims 17, 18, and 19.

Perhaps recognizing the deficiencies in the board’s 

analysis, the solicitor on appeal advances a number of 

arguments as to why the disputed claims of the ’876 

patent should be rejected as anticipated. As a general 

proposition, however, our review of a patentability determination is confined to “the grounds upon which the 

Board actually relied.” In re Applied Materials, Inc., 692 

F.3d 1289, 1294 (Fed. Cir. 2012); see Camp v. Pitts, 411 

U.S. 138, 142 (1973) (per curiam) (emphasizing that 

under the APA, “the focal point for judicial review should 

be the administrative record already in existence, not 

some new record made initially in the reviewing court”). 

We have no warrant to “accept appellate counsel’s post 

hoc rationalizations for agency action,” Burlington Truck 

Lines, Inc. v. United States, 371 U.S. 156, 168 (1962), or to

supply a reasoned justification for an agency decision that 

the agency itself has not given, Motor Vehicle Mfrs. Ass’n 

v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983); 

see In re Gartside, 203 F.3d 1305, 1314 (Fed. Cir. 2000) 

(emphasizing that a board decision “must be justified 

within the four corners of [the] record”).

We conclude, moreover, that under the circumstances 

presented here, the board erred in failing to address the 

district court’s previous interpretation of the term “cou-
14 POWER INTEGRATIONS, INC. v. LEE

pled.” There is no dispute that the board is not generally 

bound by a prior judicial construction of a claim term. See 

In re Trans Tex. Holdings Corp., 498 F.3d 1290, 1298 

(Fed. Cir. 2007). Indeed, in reexamination it applies a 

different claim construction standard than that applied by 

a district court, affording claims “their broadest reasonable interpretation consistent with the specification.” In 

re NTP, Inc., 654 F.3d 1279, 1287 (Fed. Cir. 2011) (citations and internal quotation marks omitted); see also In re 

Am. Acad. of Sci. Tech Ctr., 367 F.3d 1359, 1369 (Fed. Cir. 

2004). The fact that the board is not generally bound by a 

previous judicial interpretation of a disputed claim term 

does not mean, however, that it has no obligation to 

acknowledge that interpretation or to assess whether it is 

consistent with the broadest reasonable construction of 

the term.4 Before the board, Power Integrations repeatedly argued that the district court’s claim construction 

was the only reasonable interpretation of claim 1’s “coupled” limitation when it was viewed in light of the surrounding claim language and the specification. J.A. 817 

(“[T]he patent owner respectfully submits that a reasonable person having ordinary skill in the art would understand that when the claim is interpreted [in] the context 

of the specification and surrounding claim language, as 

required, two circuits are ‘coupled to’ each other when 

there is a connection defined between the two circuits 

such that a voltage, current or control signal passes from 

one circuit to the other[,] which is the manner in which 

4 Fairchild did not appeal the district court’s construction of the term “coupled” in claim 1 of the ’876 

patent. In 2013, after the board had denied Power Integrations’ request for rehearing, this court affirmed a jury 

verdict finding, based on the district court’s claim construction, that claim 1 of the ’876 patent was not invalid 

for obviousness. See Power Integrations II, 711 F.3d at 

1366–68.

 
POWER INTEGRATIONS, INC. v. LEE 15

the claim terms were construed by the District Court.”);

see also J.A. 720, 722, 808, 818, 821, 832, 876–77. The

board, however, declined to address—or even 

acknowledge—the district court’s claim construction. 

Given that Power Integrations’ principal argument to the 

board about the proper interpretation of the term “coupled” was expressly tied to the district court’s claim

construction, we think that the board had an obligation, 

in these circumstances, to evaluate that construction and 

to determine whether it was consistent with the broadest 

reasonable construction of the term.

We do not hold that the board must in all cases assess 

a previous judicial interpretation of a disputed claim 

term. Nor do we express any view on the merits of Power 

Integrations’ proposed construction of the term “coupled

to.” We hold only that the board on remand should carefully and fully assess whether the disputed claims of the 

’876 patent are anticipated by the prior art, setting out its 

reasoning in sufficient detail to permit meaningful appellate review. See Lee, 277 F.3d at 1346 (emphasizing that 

remand is required where a board decision “is potentially 

lawful but insufficiently or inappropriately explained”

(citations and internal quotation marks omitted)); see also 

Nazomi Commc’ns, Inc. v. Arm Holdings, PLC, 403 F.3d 

1364, 1371 (Fed. Cir. 2005) (vacating and remanding a 

district court’s claim construction determination because 

the court did “not supply the basis for its reasoning sufficient for a meaningful review”). 

CONCLUSION

Accordingly, the decision of the Board of Patent Appeals and Interferences is vacated and the case is remanded for further proceedings consistent with this 

opinion. 

COSTS

Power Integrations shall have its costs.
16 POWER INTEGRATIONS, INC. v. LEE

VACATED AND REMANDED