PTAB

IPR2017-01944

Power Integrations Inc v. Semiconductor Components Industries LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: POWER CONVERSION INTEGRATED CIRCUIT AND METHOD FOR PROGRAMMING
  • Brief Description: The ’908 patent relates to a power conversion integrated circuit for switched-mode power supplies. The circuit includes a pulse width modulated (PWM) regulator and a "state circuit" that controls the on/off state of the power supply by comparing an incoming "mode control signal" against two different reference values to place the PWM regulator into a non-operational off-state.

3. Grounds for Unpatentability

Ground 1: Anticipation by Mammano - Claims 21-22, 24-26, 28-31, 33-39, 41-44, 46-48, and 50-53 are anticipated by Mammano under 35 U.S.C. §102.

  • Prior Art Relied Upon: Mammano (Robert A. Mammano, Voltage-Mode Control Revisited – A New High-Frequency Controller Features Efficient Off-Line Performance, 1993 High Frequency Power Conversion Conference paper).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Mammano, which discloses the UCC3570 monolithic integrated controller, teaches every element of the challenged claims. The core of the argument centered on Mammano’s fault protection circuitry, which Petitioner asserted performs the exact function claimed in the ’908 patent.
    • Independent claim 21, for example, requires a power supply regulator circuit with a terminal for a "mode control signal" and a PWM regulator circuit that includes first and second comparators and a logic circuit to decode their outputs to set the PWM circuit to an off-state. Petitioner argued Mammano discloses this structure in two distinct but analogous ways:
      • Current Limit Control (for claims like 21): Mammano’s current limit pin (pin 2, “CURLIM”) receives a mode control signal (current sense voltage). This signal is compared against two different reference values (0.2V and 0.6V) by a first comparator (“Current Limit”) and a second comparator (“SHUTDOWN”/“O/C”). A logic circuit (a 2-input OR gate feeding an S/D LATCH) decodes these comparator outputs to shut down the PWM circuit, thereby anticipating the claimed structure.
      • Line Voltage Control (for claims like 26, 28, 41): Mammano’s line voltage monitor pin (pin 6, “VFWD”) receives an external disable signal corresponding to the input line voltage. This signal is compared against two different reference values (1V and 4V) by a pair of shutdown comparators (“LOW LINE”/“U/V” and “HIGH LINE”/“O/V”). A 4-input OR gate decodes the comparator outputs and generates a “PWM STOP” signal that forces the PWM output off. Petitioner contended this structure also anticipates the core claimed invention.
    • For dependent claims, Petitioner mapped additional features such as the monolithic integrated circuit package and latching circuits to corresponding disclosures in Mammano’s description of the 14-pin UCC3570 controller and its shutdown latch functionality. The same logic was applied to the challenged method claims.

4. Key Claim Construction Positions

  • Petitioner argued that the Board should decline to provide an express construction for any claim terms, as construction was not necessary for an institution decision.
  • Because the ’908 patent expired on June 4, 2017, Petitioner asserted that the claims should be given a construction consistent with the Phillips standard, interpreting terms according to their ordinary meaning in light of the knowledge of a person of ordinary skill in the art.

5. Key Technical Contentions (Beyond Claim Construction)

  • A central technical contention was that a person of ordinary skill in the art (POSITA) would have understood the correct functionality of the circuits disclosed in Mammano, despite several alleged drafting errors in its figures.
  • Petitioner argued that the functional descriptions and overall schematics in Mammano make the intended connections and operations clear. For example, Petitioner noted that the polarity of the U/V comparator inputs in Mammano's Figure 7 appeared switched, but that a POSITA would understand the correct configuration from the functional description and other figures, and thus recognize that it discloses the claimed functionality.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 21-22, 24-26, 28-31, 33-39, 41-44, 46-48, and 50-53 of the ’908 patent as unpatentable.