In re Power Integrations, Inc.

• Decision Date: 19 March 2018
• Docket Number: 2017-1304
• Citation: 884 F.3d 1370
• Parties: IN RE: POWER INTEGRATIONS, INC., Appellant.
• Court: U.S. Court of Appeals — Federal Circuit

884 F.3d 1370

IN RE: POWER INTEGRATIONS, INC., Appellant.

2017-1304

United States Court of Appeals, Federal Circuit.

Decided: March 19, 2018

Howard G. Pollack, Fish & Richardson, PC, Redwood City, CA, argued for appellant. Also represented by Michael R. Headley, Neil Warren ; 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 appellee Andrei Iancu. Also represented by Nathan K. Kelley, Thomas W. Krause, Molly R. Silfen.

Before Moore, Mayer, and Stoll, Circuit Judges.

Mayer, Circuit Judge.

Power Integrations, Inc. ("Power Integrations") appeals the remand decision of the Patent Trial and Appeal Board ("board") rejecting claims 1, 17, 18, and 19 of U.S. Patent No. 6,249,876 ("the ’876 patent") as anticipated. See In re Power Integrations, Inc. , No. 90/008,326, 2016 Pat. App. LEXIS 11870 (P.T.A.B. Oct. 4, 2016) ("Remand Decision "). Because the board’s anticipation rejections were based on an unreasonably broad claim construction, we reverse.

I. BACKGROUND

A. The ’876 Patent

The ’876 patent is entitled "Frequency Jittering Control for Varying the Switching Frequency of a Power Supply." It describes a technique for reducing electromagnetic interference ("EMI") noise "by jittering the switching frequency of a switched mode power supply." ’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. 817.

Claims 17 and 19 relate to a method for varying the switching frequency using a varying voltage to control the oscillator. 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. 819–20.

B. District Court Proceedings

The ’876 patent is no stranger to litigation. 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. See Power Integrations, Inc. v. Fairchild Semiconductor Int’l, Inc. , 422 F.Supp.2d 446, 448 (D. Del. 2006) ("Power Integrations I "), aff’d in part, rev’d in part, vacated in part , 711 F.3d 1348 (Fed. Cir. 2013) ("Power Integrations III "). It alleged that Fairchild had willfully infringed the ’876 patent, as well as U.S. Patent Nos. 4,811,075, 6,107,851, and 6,229,366. 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 two circuits to be connected in a manner "such that voltage, current or control signals pass from one to another." Id. at 455–56 (citations and internal quotation marks omitted). 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. at 455 (citations and internal quotation marks omitted). 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. A jury returned a verdict of non-obviousness and the district court denied Fairchild’s motion for judgment as a matter of law. On appeal, this court affirmed. See Power Integrations III , 711 F.3d at 1366–69. We noted that the "salient difference" between the ’876 patent and Martin is Martin’s inclusion of an erasable programmable read-only memory ("EPROM") between the counter and the digital to analog converter. Id. at 1366. We explained that Martin "always includes an EPROM memory between the counter and digital-to-analog converter" and "does not teach removing the EPROM ... as in the ’876 Patent." Id. at 1367. We also noted that "Martin’s sole figure indicates that the EPROM is just as integral as the circuit’s other components," id. , and that "Martin’s EPROM converts ordinary frequency-jittering, as in the ’876 Patent, to ‘masked’ frequency-jittering," id. at 1368. 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.

In 2016, we affirmed a jury’s determination that claim 1 was not invalid as anticipated by Martin or 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"). See Power Integrations, Inc. v. Fairchild Semiconductor Int’l, Inc. , 843 F.3d 1315, 1327–29 (Fed. Cir. 2016) (" Power Integrations V "). We explained that while both Martin and Wang "reduce the EMI signature associated with a power supply’s oscillator," they "accomplish this reduction by varying the oscillator frequency through the use of a pseudo-random code stored in read-only memory (ROM)." Id. at 1327. The "result" of this arrangement is that the frequency varies according to data stored in the memory. Id. at 1328.

We further explained that in both Martin and Wang "[t]he ROM takes the output of the upstream counter as its input," and "then outputs a different, stored value to the digital-to-analog converter." Id. at 1329. In Martin and Wang, "[t]he addition of the ROM ... ensures that no voltage, current or control signals pass from the counter to the digital-to-analog converter." Id. (citations and internal quotation marks omitted). Because Martin and Wang "decouple[ ]" the counter and the digital to analog converter, we concluded that substantial evidence supported the determination that these references did not disclose claim 1’s "coupled" limitation. Id.

C. Reexamination Proceedings

In December 2006, while district court proceedings were pending, the United States Patent and Trademark Office ("PTO") granted Fairchild’s request for ex parte reexamination of claims 1, 17, 18, and 19 of the ’876 patent. The board affirmed the examiner’s rejection of claim 1 as anticipated by Martin and Wang, as well as by 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"). See In re Power Integrations, Inc. , No. 2010–011021, 2010 Pat. App. LEXIS 19305, at *7–12 (P.T.A.B. Dec. 22, 2010) ("Power Integrations II "). 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 [they] disclose a ROM separating a counter from a digital to analog converter."Id. at *8 (citations and internal quotation marks omitted). Instead, relying on one of a number of definitions of the term "couple" in a generalist dictionary, the board determined that the term meant " ‘to join (electric circuits or devices) into a single ... circuit.’ " Id. at *7 (quoting Webster’s Third Int’l Dictionary of the English Language Unabr. 521 (Philip B. Gove ed., 1993) ("Webster’s Dictionary")).

Applying this construction, the board held that Martin, Wang, and Habetler each disclosed a counter "coupled" to a digital to analog converter because the two components were joined in one circuit. Id. at *9. The board did not address the district court’s conclusion that claim 1’s "coupled" limitation requires the counter and the digital to analog converter to be connected in a manner "such that voltage, current or control signals pass from one to another," Power Integrations I , 422 F.Supp.2d at 455–56.

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" in claim 1, the board rejected Power Integrations’ argument that Habetler did not anticipate because it includes an EPROM between the counter and the digital to analog converter. See Power Integrations II , 2010 Pat. App. LEXIS 19305, at *12. The board further rejected Power Integrations’ argument that Habetler failed to disclose the claimed primary and secondary voltage sources. See id. at *13–15.

After the board denied its petition for rehearing, Power Integrations appealed to this court. We vacated the board’s decision, stating that it had "fundamentally misconstrued Power Integrations’ principal claim construction argument and failed to provide a full and reasoned explanation of its decision to...