On March 19, 2018, the Court of Appeals for the Federal Circuit rejected, in In re Power Integrations, Inc., a PTAB decision finding that claims were invalidated as anticipated as unreasonably overbroad. The claim construction was subject in an ex parte reexamination of Power Integrations’ U.S. Patent No. 6,249,876 (‘876). ‘876 is directed to “Frequency Jittering Control for Varying the Switching Frequency of a Power Supply.” It describes a method for reducing electromagnetic interference (EMI) by “jittering” switching frequency of a switched mode power supply.
Claim 1 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.
Claim 17 is directed to a method for varying the switching frequency using varying voltage to control the oscillator, and “cycling a counter” to generate a secondary voltage which 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.
There have been seven litigations (including the current one) involving the ‘876 patent, and the prior case history is very convoluted, and is outlined below. The case numberings correspond to each litigation chronologically.
Power Integrations I
In 2004, Power Integrations sued Fairchild Semiconductor International, Inc. for patent infringement in the U.S. District Court, District of Delaware, of the ‘876 patent and three other patents. During claim construction, Power Integrations argued that “coupled” was defined as requiring two circuits to be connected in a manner “such that the voltage, current or control signals pass from one to another.” The district court adopted Power Integrations’ claim construction, noting that “it was consistent with the claim language and context of the specification.” Further, the court emphasized that “coupled” did not “require direct connection or preclude use of intermediate circuit elements.” During trial, Fairchild argued that claim 1 of ‘876 was obvious over U.S. Patent No. 4,638,417 (“Martin”), but a jury rendered a non-obviousness finding.
Power Integrations II
In 2006, Fairchild requested ex parte reexamination before the PTAB of claims 1, 17, 18, and 19 of the ‘876 patent. The PTAB affirmed the Examiner’s rejection of claim 1 as anticipated over Martin, and two other references, Wang and Habetler, relying on a definition of “coupled” from a general dictionary and disregarding the counterpart district court claim construction 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.
In affirming the Examiner’s rejection of claim 1, the PTAB rejected Power Integrations’ argument the third reference, Habetler, did not anticipate it because it includes an EPROM between the counter and the digital to analog converter. The appeal to the Federal Circuit is discussed below in Power Integrations IV.
Power Integrations III
The district court judgment from Patent Integrations I was affirmed on appeal. Martin differed from ‘876 in that Martin included an element directed to erasable programmable read-only memory (EPROM) between the counter and the digital to analog converter. The Power Integrations III Fed Circuit panel concluded that:
Martin . . . includes an EPROM memory between the counter and digital-to-analog converter and does not teach removing the EPROM as in the ‘876 patent . . . . [Therefore,] substantial evidence of objective considerations of nonobviousness supported the jury’s conclusion that claim 1 of ‘876 would not have been obvious to the ordinarily skilled artisan.
Power Integrations IV
Power Integrations’ appeal of the ex parte reexam PTAB decision was vacated and remanded by the Federal Circuit. The Fed Circuit bluntly held:
[The PTAB] 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 the 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.
Power Integrations V
In the remanded Power Integrations III case, the Fed Circuit affirmed a jury verdict that claim 1 of ‘876 was not invalid as anticipated by Martin or Wang. The Fed Circuit held that:
Martin and Wang accomplish th[e] reduction [of the EMI signature] by varying the oscillator frequency through the use of pseudo-random code stored in the ROM. The result . . . is that the frequency varies according to data stored in the memory. [Further,] the addition of the ROM ensures that no voltage, current, or control signals pass from the counter to the digital-to-analog converter. Because Martin and Wang “decoupled” 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.
The Fed Circuit panel, composed of Judges Moore, Mayer, and Stoll, noted that both the district court and the PTAB had very different definitions for “coupled.” The panel faulted the PTAB for a very broad definition, based on that of the Webster’s dictionary, to define the “coupled” limitation as “requiring only two components to be joined into a single circuit.” However, the district court concluded in light of the specification and claim language, the “coupled” limitation requires a specific control relationship between the counter and the converter. Thus, the counter must be connected to the digital to analog converter in a way that allows the counter to pass “voltage, current or control signals to it.” In other words, the counter itself drives the digital to analog converter.
The Fed Circuit panel was not amused with the PTAB’s construction:
While the broadest reasonable interpretation standard is broad, it does not give the board unfettered license to interpret the words in a claim without regard for the full claim language and the written description. The board’s claim construction here is unreasonably broad and improperly omitted any consideration of the disclosure in the specification.
Further, the panel noted that if this overly expansive definition of “coupled” were used, “every element everywhere in the same circuit is potentially ‘coupled’ to every other element in the 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.”
There were three problems with the PTAB’s analysis of claim 1. First, the plain meaning of claim 1 requires the counter to “cause” the converter to adjust the control input and to vary the switching frequency. However, there is no suggestion to take it from this to that of the prior art, where the digital to analog converter’s output to vary based on data stored in the memory.
Second, the PTAB’s construction makes the claim language meaningless. Claim 1 recites a circuit that includes a counter coupled to a digital to analog converter. However, if the PTAB’s construction were correct, the claim 1 recitation would be useless if it means merely “two components in the same circuit.”
Finally, and most importantly, the PTAB’s broad construction is unsupported by the specification.
Because the overly broad construction of “coupled” was reversed, the panel also reversed the anticipation rejection of claims 17-19 which were based on this broad claim construction.
While there are rumors of a PTAB run amok with inconsistent decision-making and generally incoherent rulings not supported by either law or factual evidence, this case is really egregious. There were several occasions during the litigative iterations that the ‘876 patent took where the PTAB made very bad judgments on claim construction. The Fed Circuit emphatically stated that it would not put up with that.
 ___F.3d___ (Fed. Cir. 2018) (Power Integrations VII), rev’g In re Power Integrations, Inc., No. 90/008,326, 2016 Pat. App. LEXIS 11870 (PTAB Oct. 4, 2016) (Power Integrations VI).
 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”).
 See Power Integrations I, supra at 455-456.
 Id. at 456.
 See In re Power Integrations, Inc., No. 2010-011021, 2010 Pat. App. LEXIS 19305, at *7-12 (PTAB Dec. 22, 2010) (Power Integrations II).
 See Power Integrations I, supra at 455-56.
 See Power Integrations II, supra at *12.
 See Power Integrations III, supra 711 F.3d at 1366-69.
 Id. at 1366.
 Id. at 1369.
 Id. at 1325.
 See Power Integrations VI, supra at *8.
 See Power Integrations I, supra at 455.
 Id. at 455-56.
 See Power Integrations VII, supra (slip op. at 10) (citations omitted).
 See MPEP 2111: “the BRI does not mean the broadest possible interpretation. Rather, the meaning given to a claim term must be consistent with the ordinary and customary meaning of the term (unless the term has been given a specific definition in the specification), and must be consistent with the use of the claim term in the specification and drawings.”