26
May
By Eric Schweibenz
On May 21, 2009, the Federal Circuit issued its opinion in Linear Technology Corporation v. ITC, No. 2008-1117.  Judge Schall, sitting on a panel with Judge Mayer and Judge Lourie affirmed-in-part, reversed-in-part, vacated-in-part and remanded the case to the ITC for further proceedings.

By way of background, the ITC instituted the underlying investigation (Certain Voltage Regulators, Components Thereof and Products Containing Same, 337-TA-564) based on Linear Technology Corporation’s (“Linear”) complaint against Advanced Analogic Technologies, Inc. (“AATI”) alleging violation of Section 337 by AATI’s importation and/or sale for importation of certain electronic voltage regulator products that infringed U.S. Patent No. 6,580,258 (the “‘258 patent”).

On May 22, 2007, the Administrative Law Judge issued an Initial Determination (“ID”), finding that AATI did not violate section 337, either because its accused products did not infringe the asserted claims or because asserted claim 35 was invalid.  On review, the ITC determined that (1) certain AATI accused products did not infringe claims 2, 3, 34 or 35, (2) claims 2, 3, and 34 were not anticipated by a reference entitled “Application Not 35 - Step Down Switching Regulators” (“AN35”), and (3) claim 35 was invalid as anticipated by a product from Maxim Integrated Products, Inc.

Regarding claim construction, there were five claim terms in dispute on appeal and the Federal Circuit affirmed the ITC’s interpretation of the first four disputed claim terms, but ruled that it improperly narrowed the “monitoring the current to the load” limitation in claim 35 of the ‘258 patent.  Specifically, the Federal Circuit determined that this limitation “can be satisfied by monitoring voltage to indirectly monitor current.”

The Federal Circuit next addressed the ITC’s infringement rulings.  Linear argued that the ITC’s finding of infringement regarding AATI’s AAT1143 product should be affirmed and the ITC’s finding of non-infringement regarding AATI’s products AAT1146, AAT1151 and AAT1265 should be reversed.  The Federal Circuit affirmed the ITC’s findings for the AAT1143, partially affirmed the findings for AAT1151 and AAT1265, and reversed the ITC’s finding on AAT1146.

In affirming the ITC’s infringement finding on AAT1143, the Federal Circuit was swayed by the circuit schematics, graphs of the device in operation, and expert testimony regarding the product.  Accordingly, the Federal Circuit found substantial evidence supporting the ITC’s infringement finding. 

In view of the similarity between AATI’s AAT1143 and AAT1146 products, the Federal Circuit also reversed the ITC’s finding of noninfringement of the AAT1146 device since such finding was not supported by substantial evidence.

The Federal Circuit’s decision to affirm the ITC’s finding of noninfringement of claims 2 and 3 of the ‘258 patent by the AAT1151 and AAT1265 devices was based on the fact that these devices lacked ZC comparator circuitry and thus did not meet the required “third circuit” limitation.  Regarding the ITC’s determination that the AAT1151 and AAT1265 products did not infringe claim 34 of the ‘258 patent, however, the Federal Circuit determined that the ITC’s findings were “internally inconsistent and not supported by substantial evidence.”  Thus, the Federal Circuit vacated the ITC’s finding of noninfringement with regard to claim 34 and remanded so that the ITC could consider whether there was infringement.

On cross appeal, AATI requested the Federal Circuit reverse the ITC’s determination that claims 2, 3, and 34 were not anticipated by AN35.  However, the Federal Circuit agreed with the ITC’s determination that the AN35 reference could not anticipate the claims because it did not show a synchronous switching voltage regulator including two transistors as required by the construed claims.

Lastly, the Federal Circuit reviewed the ITC’s determinations that claim 35 of the ‘258 patent was not infringed by the AAT1143 and AAT1146 products, as well as its ruling that claim 35 was invalid.  The Federal Circuit held that the ITC’s determinations were not supported by substantial evidence since, as noted above, such determinations were based on an incorrect claim construction of the “monitoring the current to the load” limitation in claim 35 of the ‘258 patent.  Accordingly, the Federal Circuit vacated the ITC determinations in this regard and remanded for further proceedings.
Share



Copyright © 2019 Oblon, McClelland, Maier & Neustadt, L.L.P.