In Re: Power Integrations, Inc.
Opinion
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
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 *1372 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.
,
In the wake of the trial court's claim construction, Fairchild withdrew its anticipation defense, instead arguing at trial that
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.
,
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."
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")).
*1374
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
,
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 reject claim 1 of the '876 patent as anticipated."
Power Integrations, Inc. v. Lee
,
We acknowledged that "the board is not generally bound by a prior judicial construction of a claim term" and that "in reexamination [the board] applies a different claim construction standard than that applied by a district court."
On remand, the board acknowledged that this court had expressed "concern" that its original decision had failed to assess whether the district court's interpretation of the term "coupled" was consistent with the broadest reasonable construction of the term.
Remand Decision
, 2016 Pat. App. LEXIS 11870, at *9. It concluded, however, that a comparison of its claim construction with that of the district court was "unwarranted."
In again affirming the examiner's rejection of claims 1, 17, 18, and 19 as anticipated, the board continued to adhere to a generalist dictionary definition of the term "coupled." Id. at *8. The board stated that it could "glean[ ] no substantial guidance from either the context of the claim itself or the Specification" regarding the meaning of the term. Id. The board determined, moreover, that "even if claim 1 requires the counter to drive the digital to analog converter," this "does not preclude the counter and a memory functioning together"
*1375 to cause the converter to adjust the control input. Id. at *14.
Power Integrations then appealed to this court. We have jurisdiction under
II. DISCUSSION
A. Claim Construction
"If the intrinsic record fully governs the proper construction of a term, we review the [b]oard's claim construction
de novo
."
Wasica Fin. GmbH v. Cont'l Auto. Sys., Inc.
,
B. The "Coupled" Limitation
Claim 1 of the '876 patent recites a "circuit" comprised of an oscillator, a digital to analog converter, and a counter. J.A. 817. It further specifies that "the digital to analog converter [is] 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. The district court and the board interpreted this claim language very differently. 1 Relying exclusively on a definition from Webster's Dictionary, the board determined that the "coupled" limitation requires only that two components be " 'join[ed] ... into a single ... circuit.' " Remand Decision , 2016 Pat. App. LEXIS 11870, at *8 (quoting Webster's Dictionary 521). It further determined that claim 1 does not require the counter itself to "cause" the digital to analog converter to adjust the control input and to vary the switching frequency. Id. at *14. Instead, according to the board, the claim permits a "counter and a memory functioning together" to drive the digital to analog converter. Id.
The district court, by contrast, concluded that "in light of the claim language and specification," the "coupled" limitation requires a specific control relationship between the counter and the converter.
Power Integrations I
,
"While the broadest reasonable interpretation standard is broad, it does not give the [b]oard an unfettered license to interpret the words in a claim without regard for the full claim language and the written description."
Trivascular, Inc. v. Samuels
,
Under the board's overly expansive view of the term "coupled," every element anywhere in the same circuit is potentially "coupled" to every other element in that circuit, no matter how far apart they are, how many intervening components are between them, or whether they are connected in series or in parallel.
See
In re Suitco Surface, Inc.
,
"[C]laim construction must begin with the words of the claims themselves."
Amgen Inc. v. Hoechst Marion Roussel, Inc.
,
Another problem with the board's claim construction is that it renders claim language meaningless. As discussed above, claim 1 begins by reciting a "circuit" that includes both a counter and a digital to analog converter. J.A. 817. The phrase "the digital to analog converter [is] coupled to the counter," J.A. 817, would be superfluous if, as the board said, it means only that the two components are in the same circuit.
See, e.g.
,
Bicon, Inc. v. Straumann Co.
,
Even more fundamentally, the board's unduly broad reading of the language of claim 1 is unsupported by the specification.
See
PPC Broadband, Inc. v. Corning Optical Commc'ns RF, LLC
,
Notably, moreover, every embodiment disclosed in the '876 patent shows a counter that passes voltage, current, or control signals to the digital to analog converter.
See
Astrazeneca AB, Aktiebolaget Hassle, KBI-E, Inc. v. Mut. Pharm. Co.
,
In the board's view, claim 1 can be expanded to encompass a circuit in which the switching frequency varies based on data from a memory because neither the claim language nor the specification "requir[es] the lack of a memory."
Remand Decision
, 2016 Pat. App. LEXIS 11870, at *13. This reasoning is unpersuasive. "The correct inquiry in giving a claim term its broadest reasonable interpretation in light of the specification is not whether the specification proscribes or precludes some broad reading of the claim term adopted by the examiner."
In re Smith Int'l, Inc.
,
C. The Anticipation Rejections
Because the board's decision affirming the examiner's rejection of claim 1
*1378
was based on an erroneous claim construction and the rejection is not supported under the proper construction, we reverse the rejection of claim 1.
See, e.g.
,
Smith
,
The board's unreasonably broad claim construction also mandates reversal of its anticipation rejections of claims 17, 18, and 19. Independent claim 17 contains a "coupled" limitation similar to that in claim 1, reciting "a counter coupled to one or more *1379 secondary voltage sources to generate a secondary voltage which varies over time," J.A. 820. The Director does not dispute that a reversal of the board's rejection of claim 1 also mandates reversal of its rejections of claims 17, 18, and 19. 3
The board has had two opportunities to come up with a sustainable interpretation that differs from the one that survived litigation and has failed. We conclude there is not one. The district court's construction of "coupled," an interpretation firmly rooted in the plain claim language and the specification, comports with the broadest reasonable construction of the term.
III. CONCLUSION
Accordingly, the decision of the Patent Trial and Appeal Board affirming the examiner's rejections of claims 1, 17, 18, and 19 is reversed.
REVERSED
We have twice applied the district court's construction of the "coupled" limitation.
See
Power Integrations V
,
Martin relies on an EPROM to vary the frequency in a "pseudo-random" manner. J.A. 1443. An oscillator generates the switching frequency, and then part of the oscillator's output is "fed back to [the] counter," which sends a signal to the memory that "selectively steps" the memory "through its addressing routine" for varying the switching frequency. J.A. 1443. The memory relays its instructions to the digital to analog converter, which transforms those digital instructions to an analog signal that is supplied to the oscillator. J.A. 1443.
Wang describes a method of programming a memory to vary the switching frequency of a circuit used with a DC-to-DC converter. J.A. 1453-62. In the Wang system, an oscillator generates a signal having a switching frequency and part of that signal is sent to the counter. J.A. 1461. The counter then sends signals to a memory. J.A. 1461. Next, the memory sends its programmed instructions to a pair of digital to analog converters, which relay the memory's instructions on how to vary the switching frequency to the oscillator. J.A. 1461.
Habetler is directed to reducing acoustic noise in an inverter-driven electric machine. J.A. 1445-52. In the Habetler system, a triangle generator generates a switching frequency which is relayed, in part, to a counter. J.A. 1448. The counter sends signals to the memory, which contains "a large quantity of periodic random numbers" that are used to vary the switching frequency. J.A. 1448. The memory then sends instructions to the digital to analog converter. J.A. 1448.
Because we conclude that Habetler does not disclose the "coupled" limitation of claims 17, 18, and 19, we need not reach Power Integrations' alternative argument that Habetler does not disclose "generating a primary voltage," a "voltage-controlled oscillator," or "one or more secondary voltage sources to generate a secondary voltage." J.A. 819-20.
Reference
- Full Case Name
- In RE: POWER INTEGRATIONS, INC., Appellant.
- Cited By
- 15 cases
- Status
- Published