Ex Parte Randazzo

Board of Patent Appeals and Interferences

Jun 29, 2012

10835936 (B.P.A.I. Jun. 29, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
10/835,936 04/30/2004 Todd A. Randazzo 03-1392/L13.12-0248 1260
7590 06/29/2012
Leo J. Peters
LSI Logic Corporation
MS D-106
1621 Barber Lane
Milpitas, CA 95035
EXAMINER
HU, RUI MENG
ART UNIT PAPER NUMBER
2618
MAIL DATE DELIVERY MODE
06/29/2012 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte TODD A. RANDAZZO
____________

Appeal 2010-002783
Application 10/835,936
Technology Center 2600
____________

Before JOHN A. JEFFERY, DENISE M. POTHIER, and
THOMAS L. GIANNETTI, Administrative Patent Judges.

JEFFERY, Administrative Patent Judge.

DECISION ON APPEAL

Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1-7, 9-15, and 17-19. We have jurisdiction under 35
U.S.C. § 6(b). We reverse.

Appeal 2010-002783
Application 10/835,936

2
STATEMENT OF THE CASE
Appellant’s invention is a resistive voltage regulator for integrated
circuit receivers. See generally Title; Abstract. Claim 1 is illustrative with
key disputed limitations emphasized:
1. An integrated circuit comprising:
first and second power supply terminals;
a ground supply terminal;
a resistive element coupled between the first and second power
supply terminals, wherein the voltage on the second power supply
terminal varies in part as a positive function of the voltage on the first
power supply terminal and in part as an inverse function of a bias
current drawn through the resistive element; and
a receiver biased between the second power supply terminal
and the ground supply terminal, wherein the receiver draws the bias
current through the resistive element, which varies as a positive
function with a voltage on the second power supply terminal and has
a greater than linear dependence on the voltage on the second power
supply terminal such that changes in the bias current limit changes in
the voltage on the second power supply terminal through the resistive
element due to changes in the voltage on the first power supply
terminal.

THE REJECTIONS
1. The Examiner rejected claims 1, 4, 5, 9, 12, 13, and 17-19
1
under
35 U.S.C. § 103(a) as unpatentable over Appellant’s prior art admission
(―AAPA‖) and Oki (US 2002/0060558 A1; May 23, 2002). Ans. 3-9.
2,3

1
Although the Examiner includes claim 8 in this rejection, we omit that
claim here since it was cancelled. And while the Examiner omits claims 12
and 13 from this rejection, they were, nonetheless, included in the body of
the rejection (Ans. 5). We therefore include claims 12 and 13 for clarity.
Footnote continued on the next page.

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Application 10/835,936

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2. The Examiner rejected claims 2, 7, 10, and 15 under 35 U.S.C.
§ 103(a) as unpatentable over AAPA, Oki, and Shibata (US 5,570,004; Oct.
29, 1996). Ans. 9-10.
3. The Examiner rejected claims 3 and 11 under 35 U.S.C. § 103(a)
as unpatentable over AAPA, Oki, Shibata, and Vladislav (US 6,703,813 B1;
Mar. 9, 2004). Ans. 10-11.
4. The Examiner rejected claims 6 and 14 under 35 U.S.C. § 103(a)
as unpatentable over AAPA, Oki, and Vladislav. Ans. 11.

THE OBVIOUSNESS REJECTION OVER AAPA AND OKI
The Examiner finds that Figure 1 of the present application (―AAPA‖)
discloses an integrated circuit with every recited feature of representative
claim 1 including (1) a ―resistive element‖ (transistor ―MN1‖) coupled
between first and second power supply terminals corresponding to the

See App. Br. 2 (noting cancellation of claim 8 and rejection of claims 12 and
13); Ans. 2 (confirming this status as correct).
2
Throughout this opinion, we refer to (1) the Appeal Brief filed June 12,
2009; (2) the Examiner’s Answer mailed August 31, 2009; and (3) the Reply
Brief filed November 2, 2009.
3
Although the Examiner cites an additional reference (Tobita) in the body of
this rejection (Ans. 5, 7-8), the statement of the rejection (or any other
rejection) does not refer to this reference. Since this reference is not further
discussed in the Briefs or Answer, its relevance to the contested issues on
appeal is unclear on this record, and we therefore decline to further consider
it here in the first instance. Our decision is therefore based on the rejection
of claims 1, 4, 5, 8, 9, and 17-19 solely over AAPA and Oki. Accord App.
Br. 7 (omitting Tobita from the ―GROUNDS OF REJECTION TO BE
REVIEWED ON APPEAL‖ section); Ans. 2 (confirming this status as
correct).
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Application 10/835,936

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transistor’s drain and source nodes, respectively, and (2) a receiver 12 that is
said to draw bias current through the resistive element which, according to
the Examiner, has a greater than linear dependence on the second power
supply terminal’s voltage. Ans. 3-4. Although the Examiner acknowledges
that this voltage does not vary in part as an inverse function of the drawn
bias current, the Examiner cites Oki as teaching this feature in concluding
that the claim would have been obvious. Ans. 3-5, 12-16.
Appellant argues that not only is AAPA opposite to the claimed
invention since voltage VREC is controlled to equal VREF, but modifying
AAPA as proposed would destroy its functionality. App. Br. 8-10.
Appellant adds that Oki also does not disclose (1) varying the second power
supply terminal’s voltage as an inverse function of the drawn bias current,
and (2) a greater than linear dependence within the combination of the
receiver and resistive element as claimed. App. Br. 10-12; Reply Br. 2-8.

ISSUE
Under § 103, has the Examiner erred in rejecting claim 1 by finding
that AAPA and Oki collectively would have taught or suggested (1) varying
the second power supply terminal’s voltage as an inverse function of a bias
current drawn through a resistive element, and (2) the drawn current has a
greater than linear dependence on the second power supply terminal’s
voltage?

ANALYSIS
Based on the record before us, we find error in the Examiner’s
obviousness rejection of independent claim 1 for the reasons indicated by
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Application 10/835,936

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Appellant. App. Br. 8-12; Reply Br. 1-8. As Appellant points out (App. Br.
11-12; Reply Br. 7), a key aspect of the claimed invention is the combination
of (1) the greater than linear dependence of the bias current drawn by the
receiver, and (2) the resistive element that allows voltage drop across this
element to increase or decrease with changes in the current drawn by the
receiver. Since the receiver’s internal bias current has a very strong function
of the output voltage (VREC), Appellant’s circuit provides a negative
feedback that improves control of this voltage over conventional regulators
such as that shown in Appellant’s prior art Figure 1. As shown in that
figure, the operational amplifier provides a constant voltage on VREC based
on a reference voltage (VREF) regardless of the current drawn by the
receiver. App. Br. 3-4; Reply Br. 2-3. Notably, Appellant’s resistive
element consumes less area and power on an integrated circuit than the
regulator in Figure 1 and is less complex. Spec. 11:18-22.
Turning to the rejection, the Examiner maps transistor MN1 in
Appellant’s prior art Figure 1 to the recited ―resistive element.‖ Ans. 4. But
as Appellant indicates (App. Br. 13; Reply Br. 6-7), transistor MN1 is not
operated in its linear range as a resistor, as is the case with transistor MP6 in
Appellant’s Figure 3. This is a crucial defect in the Examiner’s rejection, for
even assuming that transistor MN1 has some internal resistance,
4
the voltage
drop across MN1 may not vary with changes to VDD in its normal operating
range as Appellant indicates. Reply Br. 6. Indeed, when the transistor
functions as a closed switch, the voltage drop across MN1 would be

4
Accord Ans. 17 (noting that since transistor MN1 inherently consumes part
of voltage VDD, the transistor is a ―resistive element‖).
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Application 10/835,936

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negligible. In any event, we fail to see what effect, if any, such a drop has
on the output voltage since the transistor is biased by the operational
amplifier so that VREC equals VREF (the reference voltage obtained via a
voltage divider (resistors R1 and R2)) regardless of the receiver’s drawn
current as Appellant indicates. Reply Br. 7.
The Examiner’s position regarding the receiver’s drawn bias current
having a greater than linear dependence on the second power supply
terminal’s voltage is likewise problematic. Leaving aside the fact that the
Examiner fails to squarely address this critical aspect of the claimed
invention in the rejection (see Ans. 4),
5
as Appellant indicates (Reply Br. 5-
6), the Examiner’s analysis in this regard in the Response to Arguments
refers to elements of Appellant’s invention in Figure 3—not the prior art
shown in Figure 1. See Ans. 14-15 (referring to Spec. 9:13–10:10, resistive
element 20, and receiver 22).
Nevertheless, the Examiner’s reasons that AAPA and Oki collectively
teach that the bias current (that is adjusted via feeding back VREC to the
operational amplifier) has a greater than linear dependence on the second
power supply terminal’s voltage (i.e., the fed-back VREC). Ans. 15-16. We
find this position unavailing. First, this analysis is unclear in light of the
Examiner’s proposed modification to Appellant’s Figure 1 in view of Oki,
namely, to replace AAPA’s VREF circuit (R1/R2) with Oki’s circuit 5 and

5
Although the Examiner indicates that the receiver 12 ―draws a bias current
through the resistive element (MN1), which varies as a positive function
with a voltage on the second power supply terminal,‖ the Examiner’s
rejection does not address the second aspect of this bias current, namely its
greater than linear dependence on that voltage. See Ans. 4.
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Vref to bias the receiver 12 (Ans. 5, 13; emphasis added). In light of this
proposed modification, rationale for the Examiner’s apparent reliance on the
functionality of Oki’s feedback control circuit 10 that adjusts the bias current
IE is unclear, for not only does Oki not have a receiver, but AAPA already
has a circuit that feeds back VREC to operational amplifier 14 to bias
transistor MN1. To the extent that the Examiner proposes to modify,
replace, or augment Appellant’s feedback circuit in Figure 1 with Oki’s
feedback circuit 10, the record is unclear, particularly in light of the
Examiner’s stated modification involving only Oki’s circuit 5 and Vref noted
above. See Ans. 5, 13. In any event, even assuming that this is the
Examiner’s intention, while Oki feeds a divided output voltage back to an
operational amplifier 2 to adjust emitter current IE, we cannot say—nor has
the Examiner shown—that this arrangement establishes the bias current
having a greater than linear dependence on that voltage to achieve the
voltage limiting results as claimed.
Nor do we agree with the Examiner (Ans. 13-14) that Oki’s feedback
circuit teaches the second power supply terminal voltages varying in part as
an inverse function of the bias current as claimed. As Appellant indicates
(App. Br. 10-11; Reply Br. 7-8), Oki’s output voltage VOUT varies as a
positive function of the emitter current IE—not as an inverse function. See
Oki, ¶ 0018 (noting that an increased flow of emitter current IE raises the
output voltage VOUT). The Examiner’s position to the contrary (Ans. 13-14)
is unavailing, for the Examiner’s ―inverse function‖ is based on comparing
the output voltage level determined before raising or lowering the emitter
current that adjusts the voltage to a different level. Notably, this adjustment
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Application 10/835,936

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occurs due to a positive function between the emitter current and output
voltage—not an inverse function.
We are therefore persuaded that the Examiner erred in rejecting (1)
independent claim 1; (2) independent claims 9 and 19, which recite
commensurate limitations; and (3) dependent claims 4, 5, 12, 13, 17, and 18
for similar reasons.

THE OTHER OBVIOUSNESS REJECTIONS
Since the Examiner has not shown that the other cited prior art cures
the deficiencies noted above regarding the independent claims, we reverse
the obviousness rejections of dependent claims 2, 3, 6, 7, 10, 11, 14, and 15
(Ans. 9-11) for similar reasons. Since this issue is dispositive of our
decision reversing the rejection of these claims, we need not address
Appellant’s other arguments regarding claim 2. App. Br. 14.

CONCLUSION
The Examiner erred in rejecting claims 1-7, 9-15, and 17-19 under
§ 103.

ORDER
The Examiner’s decision rejecting claims 1-7, 9-15, and 17-19 is
reversed.

REVERSED

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