PTAB

IPR2018-01818

Semiconductor Components Industries LLC v. Power Integrations Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Controller for a Power Converter
  • Brief Description: The ’483 patent relates to controllers for switching power converters, specifically flyback converters. The disclosed technology uses a signal from a single terminal connected to an auxiliary transformer winding to represent both the converter's input line voltage and its output voltage at different times during the switching cycle for control purposes.

3. Grounds for Unpatentability

Ground 1: Obviousness over Spampinato and Mobers - Claims 6, 8, 9, 12, and 13 are obvious over Spampinato in view of Mobers.

  • Prior Art Relied Upon: Spampinato (Patent 6,061,257) and Mobers (Patent 6,542,386).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Spampinato disclosed a base flyback converter with a controller that uses an auxiliary winding to sense a signal representative of the output voltage (during switch off-time) for short-circuit protection. Mobers was cited for its explicit teaching that the same type of auxiliary winding can be used to sense a signal representative of both the output voltage (for over-voltage protection) and the input line voltage (for over-power protection). Mobers further taught the advantage of detecting this plural information via a "single input pin" on its integrated circuit controller. The combination of these references, Petitioner asserted, disclosed all limitations of the challenged claims. Specifically for dependent claim 6, Spampinato's sensor monitored a voltage, while Mobers taught sensing the input line voltage information as a current signal, mapping directly to the claim's voltage/current dichotomy. For claims 8, 12, and 13, both references taught or suggested integrating the controller and power switch onto a single integrated circuit.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Mobers's teaching of an over-power protection system with the similar flyback converter of Spampinato. Petitioner contended this was a straightforward application of a known technique (Mobers's protection circuit) to improve a similar device (Spampinato's power supply). The nearly identical current-mode control architectures of both references would have made the integration simple and its results predictable.
    • Expectation of Success: Given the similar architectures and the explicit teachings in Mobers about using a single pin for dual-voltage sensing, a POSITA would have had a high expectation of success in implementing Mobers's protection scheme into Spampinato's converter to achieve the same benefits.

Ground 2: Obviousness over Spampinato - Claim 8 is obvious over Spampinato.

  • Prior Art Relied Upon: Spampinato (Patent 6,061,257).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Spampinato, standing alone, rendered claim 8 obvious. Spampinato’s own figures and description illustrated that the signal received at the sensor's single input terminal (the "DEM" pin) inherently contained information about both the output voltage (as a positive voltage swing during the switch's off-time) and the input line voltage (as a negative voltage swing during the on-time). This phenomenon was presented as a natural and unavoidable consequence of the magnetic coupling in Spampinato's disclosed flyback converter architecture. Petitioner further argued that Spampinato explicitly contemplated the integration of the power switch into its integrated circuit controller, thus meeting all limitations of claim 8.
    • Motivation to Combine (Rationale): This argument was not based on a combination of references. Instead, it relied on the assertion that the claimed features were inherently present in Spampinato's disclosure. The motivation was simply to build the device as disclosed by Spampinato.
    • Key Aspects: This ground's strength depended heavily on Petitioner's proposed claim construction for "to represent," which argued that the signal need only contain the information, without requiring the sensor to actually use or act upon both the input and output voltage information.

4. Key Claim Construction Positions

  • "to represent" (Claim 1): Petitioner argued this term required no formal construction and should be given its plain and ordinary meaning. The core of the contention was that this language defined the inherent characteristics of the signal received by the sensor, not the functions or operations that the sensor must perform. According to Petitioner, the claim did not require the sensor to process, respond to, or otherwise use the information representing both the input and output voltage. It only required that the signal received at the single terminal inherently contain both pieces of information at the specified times, a condition met by the prior art even if the prior art sensor only used one piece of that information.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 6, 8, 9, 12, and 13 of the ’483 patent as unpatentable under 35 U.S.C. §103.