Appeal 2007-1647
Application 10/631,841
After carefully considering all of the evidence before us, we cannot
affirm the Examiner on this record. We find there is nothing in the record
that indicates the recited “lower supply voltage” and “ground reference
point” have the same voltage potential (Claim 1). Indeed, as is conventional,
“ground” typically refers to a zero-volt reference point in a circuit. Because
the instant invention is directed to reducing or eliminating the adverse
biasing effects of “ground noise” (i.e., Vss noise), such noise clearly
represents a voltage potential between a ground reference point and a lower
supply voltage (Vss).5 In particular, we find the Examiner’s proffered
combination of AAPA and Rapp does not show a large capacitor coupled
between a bias node and a lower supply voltage (i.e., that is not ground).
AAPA has no large capacitor connected between b1 and Vss (Fig. 1). The
Examiner looks to Rapp for the missing capacitor. However, Rapp’s
transistor 90 (functioning as a capacitor)6 is clearly shown in Fig. 5 as being
connected between the gate (bias point) of transistor 86 and a ground
reference point.
Moreover, we find it highly unlikely that transistor 90 (functioning as
a capacitor, see Rapp, col. 9, ll. 40-41) would reasonably possess the level of
capacitance typically associated with a “large capacitor,” as claimed by the
instant invention. Indeed, while a parasitic capacitance is associated with a
5 See Specification, page 62, paragraph 0016: “The ground noise (VSS
noise), as described above, is developed between the lower supply voltage
VSS and the ground reference voltage.”
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