PTAB

IPR2017-01819

NVIDIA Corp v. Polaris Innovations Ltd

Key Events

Petition

petition

Title: Method And Apparatus for Internally Trimming Output Drivers and Terminations in Semiconductor Devices
Brief Description: The ’325 patent describes a method for adjusting ("trimming") the impedance of interface devices on an integrated circuit to improve data transmission rates. The purported invention is a "trimming unit" located within the semiconductor device itself that compares a measured voltage from the interface device to a nominal voltage and adjusts the device's impedance accordingly.

Prior Art Relied Upon: Volk (Patent 6,693,450).
Core Argument: Volk 450 disclosed a semiconductor device with an on-chip "tuner" that dynamically adjusts the impedance of an output driver, anticipating all limitations of the challenged claims.
Prior Art Mapping: Petitioner argued that Volk 450's driver 56 is an "interface device" with a "settable control element" (the programmable pull-down driver element 82). The "trimming register" is met by adder 98, which stores a value used to control the impedance. The "trimming unit" is disclosed as tuner 72, which includes a comparator 90 that compares a measured feedback voltage from the data line against a reference voltage (VSWING) and a tuner controller 100 that writes to the adder 98 based on the comparison, thereby trimming the impedance. Dependent claims 16-18 were argued to be met by Volk 450's disclosure of a reference voltage device (RCOMP controller 64), a voltage divider, a comparator unit (90), a logic unit (tuner controller 100), and a memory unit (96).

Prior Art Relied Upon: Volk (Patent 6,356,105).
Core Argument: Volk 105 disclosed a self-adjusting impedance control system for a termination bus in a system logic chip that anticipates the claimed invention.
Prior Art Mapping: Petitioner asserted that Volk 105's termination circuit, including RCOMP pad 472, constitutes an "interface device," and its adjustable transistors (P1, N1) are the "settable control elements." The "trimming register" is taught by the up/down counters (450, 456) which store impedance values. The "trimming unit" is comprised of comparators (458, 460) that compare the pad voltage to reference voltages (VUP, VDN) and a control logic state machine (402) that directs the counters to adjust the stored value. Dependent claim 16's reference voltage device and voltage divider, and claim 17's comparator and logic units were also argued to be expressly disclosed within this system.

Prior Art Relied Upon: Volk (Patent 6,693,450) and Hiraki (Patent 6,201,733).
Core Argument for this Ground: Volk 450 teaches all elements of claims 14, 16, and 17. Hiraki supplied the "nonvolatile memory unit" of claims 18 and 20, and a POSITA would combine these teachings for improved efficiency.
Prior Art Mapping: Hiraki taught storing "voltage trimming information" in a non-volatile flash memory and loading it into a trimming register upon system reset. This was argued to directly teach the limitations of claim 18 (a nonvolatile memory unit programmed with a trimming value) and claim 20 (the memory unit is configured for loading the trimming register).
Motivation to Combine: The trimming system in Volk 450 is volatile; its adder loses the stored impedance value upon reset, requiring the system to "start from scratch" each time. A POSITA would combine Hiraki's well-known technique of using non-volatile memory to store the last-used trimming value, allowing for a much faster and more efficient re-calibration after a reboot.
Expectation of Success: Petitioner asserted the combination involved applying a known solution (storing configuration data in non-volatile memory) to a known problem (loss of state on power-down), which would have been a straightforward implementation with a high expectation of success.

Prior Art Relied Upon: Volk (Patent 6,356,105) and Hiraki (Patent 6,201,733).
Core Argument for this Ground: As with the previous ground, Volk 105 taught the base invention, and Hiraki provided the non-volatile memory element for claims 18 and 20.
Motivation to Combine: The motivation was identical to that in Ground 3. The U/D counters in Volk 105 are volatile and lose their state on reset. A POSITA would have been motivated to incorporate Hiraki's non-volatile memory to preserve the trimming information across power cycles, thereby improving system efficiency.

interface device: Petitioner noted the Board, in a prior IPR, construed this term as a device "associated with an interface" and "between the semiconductor device' and 'another device external to the semiconductor device.'" Petitioner argued that the prior art drivers (Volk 450) and termination circuits (Volk 105) meet this construction.
settable control element: Petitioner argued that while no construction is necessary, the prior art meets the Patent Owner's previously proposed construction of "a circuit element, the impedance of which can be programmed, adjusted, or set." The programmable driver elements of Volk 450 and adjustable transistors of Volk 105 were argued to satisfy this.

Petitioner argued that discretionary denial under §325(d) would be unwarranted. Although this was a second petition, it was based on different prior art than the first petition, which was denied institution. Crucially, Petitioner asserted that this petition was drafted to address the Board's claim construction of "interface device" from the prior proceeding, a construction Petitioner could not have known before the first denial.

Petitioner requested institution of an IPR and cancellation of claims 14, 16-18, and 20 of the ’325 patent as unpatentable.