Opinion ID: 208680
Heading Depth: 3
Heading Rank: 3

Heading: a second control signal ... to cause both transistors to be OFF

Text: AATI also contests the Commission's construction of the language a second control signal ... to cause both transistors to be OFF, which is required by claims 2 and 3, but not method claim 34. The Commission construed this language as broad enough to cover a signal which causes, or ultimately results in, both switching transistors being OFF. Final Determination, slip op. at 50. AATI argues that the proper construction of this language requires the third circuit [to] produce[ ] a signal whose transition necessarily leads to both transistors being OFF, without the intervention of any other independently-generated signal. According to AATI, this is because including ultimately results in removes the concept of causation and, therefore, is contrary to the claim language itself. Linear and the Commission defend the current construction, contending that the language, and in particular cause, was correctly given its broad ordinary meaningto make happen, to result in, requiring neither a direct nor immediate cause. We hold that the Commission properly construed the limitation a second control signal ... to cause both transistors to be OFF as requiring the second control signal to neither directly cause both transistors to be OFF nor be entirely distinct from the first control signal. The '258 patent's specification does not indicate that the second control signal must directly cause both transistors to be OFF. Indeed, a direct causation requirementwithout the intervention of other signals or componentswould be nearly unworkable to articulate or ascertain. Also, such a requirement would allow an accused infringer to evade infringement by merely identifying an intermediary signal or component that allegedly breaks the chain of causation. Cf. Resonate Inc. v. Alteon Websys., Inc., 338 F.3d 1360, 1365 (Fed.Cir.2003) (The patentee's ... choice not to specify a transmission path from the server to the client did not require direct transmission to the client because such a rule likely would prove unworkable.). In addition, such a requirement would be contrary to the specification, which in fact discloses components that are located between the generation of the second control signal and the switching transistors. See, e.g., '258 patent fig.2. Tellingly, in construing the nearly identical, but more restrictive, claim limitations of the parent '178 patent, we held that to cause both switching transistors to be simultaneously OFF for a period of time should not be construed to include a narrow causation requirement. See Linear Tech., 379 F.3d at 1324 (holding that the district court construed the limitations too narrowly because simultaneously merely requires a condition to exist at the same time or concurrently, encompasses the simultaneous state of both switching transistors being disabled or held off, and does not require the switching transistors to be turned off or disabled at the same instant). Nor does the specification indicate that the second control signal must be entirely distinct from the claimed first control signal. In fact, the specification discloses the contrarythat a portion of the first control signal impacts whether the second control signal turns both transistors OFF. Indeed, figure 2 discloses that the signal from hysteretic comparator 74 in combination with the signal 25A from constant off time one-shot circuit 25part of the disclosed first control signal that var[ies] the duty cycle of the switching transistorscause[s] both switching transistors to be OFF. See, e.g., '258 patent fig.2; id. col.6 ll.38-55. Thus, the patent shows that the first control signal can be a part of the second control signal, precluding a requirement that the two control signals must be entirely distinct. The Commission's construction of a second control signal ... to cause both transistors to be OFF is correct.