Volterra Semiconductor LLC

Patent Trials and Appeals Board

Mar 30, 2020

14838805 - (D) (P.T.A.B. Mar. 30, 2020)

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.
14/838,805 08/28/2015 Michael D. McJimsey 570495 8169
143959 7590 03/30/2020
Lathrop Gage LLP / Maxim Integrated
2440 Junction Place
Suite 300
Boulder, CO 80301
EXAMINER
TRAN, NGUYEN
ART UNIT PAPER NUMBER
2838
NOTIFICATION DATE DELIVERY MODE
03/30/2020 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
patent@lathropgage.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte MICHAEL D. MCJIMSEY, ANTHONY J. STRATAKOS,
ILIJA JERGOVIC, XIN ZHANG, KAIWEI YAO, VINCENT W. NG,
PHONG T. NGUYEN, ARTIN DER MINASSIANS, and
RYAN JAMES RICCHIUTI
____________

Appeal 2019-003292
Application 14/838,805
Technology Center 2800
____________

Before MICHAEL P. COLAIANNI, N. WHITNEY WILSON, and
JANE E. INGLESE, Administrative Patent Judges.

INGLESE, Administrative Patent Judge.

DECISION ON APPEAL
Appellant1 requests our review under 35 U.S.C. § 134(a) of the
Examiner’s decision to finally reject claims 1, 2, and 21.2 We have
jurisdiction over this appeal under 35 U.S.C. § 6(b).
We REVERSE.

1 We use the word “Appellant” to refer to the “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies Volterra Semiconductor LLC as the
real party in interest. Appeal Brief filed October 22, 2018 (“Appeal Br.”)
at 2.
2 Final Office Action entered April 11, 2018 (“Final Act.”) at 1.
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CLAIMED SUBJECT MATTER
Appellant claims a method for transferring electric power between an
electric power source and a load using a maximum power point tracking
controller. Appeal Br. 3–4. Claim 1, the sole pending independent claim,
illustrates the subject matter on appeal, and is reproduced below with
contested subject matter italicized:
1. A method for transferring electric power between an
electric power source and a load using a maximum power point
tracking controller, comprising:
controlling switching of a control switching device of the
maximum power point tracking controller, based at least
in part on a signal representing current flowing through
energy storage inductance of the maximum power point
tracking controller and a reference signal, to regulate a
voltage across the electric power source, such that the
voltage across the electric power source is greater than or
equal to a voltage across the load;
multiplying a signal representing voltage across an output port
of the maximum power point tracking controller by a
signal representing current flowing through the output
port of the maximum power point tracking controller, to
generate a signal representing power transferred to the
load; and
varying the reference signal so that the signal representing
power transferred to the load is maximized.

Appeal Br. 12 (Claims Appendix) (emphasis added).
REJECTIONS
The Examiner maintains the following rejections in the Examiner’s
Answer entered January 25, 2019 (“Ans.”):
I. Claims 1 and 2 under 35 U.S.C. § 103(a) as unpatentable over
Farrington et al. (US 5,391,976, issued February 21, 1995) in view of
Shimada et al. (US 6,882,551 B2, issued April 19, 2005); and
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Application 14/838,805

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II. Claim 21 under 35 U.S.C. § 103(a) as unpatentable over
Farrington in view of Shimada and Melanson (US 7,894,216 B2, issued
February 22, 2011).
FACTUAL FINDINGS AND ANALYSIS
Upon consideration of the evidence relied upon in this appeal and
each of Appellant’s contentions, we reverse the Examiner’s rejections of
claims 1, 2, and 21 under 35 U.S.C. § 103(a), for reasons set forth in the
Appeal and Reply Briefs, and below.
Claim 1 requires the recited method for transferring electric power
between an electric power source and a load using a maximum power point
tracking controller to comprise, in part, controlling switching of a control
switching device of the controller based at least in part on a reference signal,
and varying the reference signal so that a signal representing power
transferred to the load is maximized. Claim 1 recites generating the signal
representing power transferred to the load by multiplying a signal
representing voltage across an output port of the maximum power point
tracking controller by a signal representing current flowing through the
output port of the maximum power point tracking controller.
The Examiner finds that Farrington discloses a method for
transferring electric power between full-wave rectifier 205 (power source)
and load 240 comprising controlling switching of switching type converter
230 (control switching device) based at least in part on fixed reference signal
Vref. Final Act. 2–3 (citing Farrington Fig. 2); Ans. 6. The Examiner finds
that Farrington discloses that switching type converter 230 (control
switching device) may be configured as a boost converter to step up output
voltage. Ans. 5–6. The Examiner determines that “[a]s the output voltage
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Application 14/838,805

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increases the power transfer to the load is increased. Therefore, the power
transferred to the load is maximized.” Ans. 6. The Examiner finds that
“Farrington fails to disclose ‘varying the reference signal so that the signal
representing power transferred to the load is maximized’ since Farrington’s
Fig. 2 shows the output voltage Vout is controlled in response to a fixed
voltage reference Vref.” Id.
The Examiner finds, however, that Shimada discloses a step-up
chopper circuit that steps up output voltage Vout to a higher voltage, and,
therefore, is “considered as a boost converter.” Ans. 6–7 (citing Shimada
col. 1, ll. 39–47; Fig. 2). The Examiner finds that Shimada discloses that the
step-up chopper circuit includes controller 8 that controls Vout in response
to variable reference voltage Vref1. Ans. 7 (citing Shimada col. 3, ll. 50–60;
Fig. 2). Based on this disclosure in Shimada, the Examiner determines that
“the power transfer to load is dependent on the output current and voltage
because, as the output voltage increases the power transfer to the load is
increase, the power transferred to the load is maximized.” Ans. 7.
The Examiner concludes that “[i]t would have been obvious to one
with ordinary skill in the art to have modified the circuit of Farrington’s
invention with the variable reference voltage as disclose by Shimada so that
the signal representing power transferred to the load is maximized.” Id.
On the record before us, however, the Examiner does not provide a
sufficient factual basis to establish that a combination of the relied-upon
disclosures of Farrington and Shimada would have suggested varying a
reference signal so that a signal representing power transferred to a load is
maximized, as required by claim 1.
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As discussed above, claim 1 recites generating a signal representing
power transferred to a load by multiplying a signal representing voltage
across an output port of a maximum power point tracking controller, by a
signal representing current flowing through the output port of the maximum
power point tracking controller. The signal representing power transferred
to the load is, therefore, the product of a signal representing output voltage
and a signal representing output current. As Appellant points out, even if
Farrington and Shimada disclose boost converters that increase the voltage
output to a load as the Examiner finds, increasing the output voltage would
not necessarily increase the power transferred to the load, because power is
the product of voltage and current. Reply Br. 3–4.
Furthermore, even if Farrington and Shimada would have suggested
increasing the power transferred to a load as the Examiner asserts, the
Examiner does not identify any disclosure in Farrington and Shimada,
considered individually and in combination, which would have suggested
varying a reference signal so that a signal representing power transferred to
the load is maximized. Rather, the Examiner merely asserts in conclusory
fashion that, because Farrington’s switching type converter 230 (control
switching device) may be configured as a boost converter to step up the
output voltage, “the power transfer to the load is increased. Therefore, the
power transferred to the load is maximized.” Ans. 6. The Examiner,
however, does not identify any disclosure in Farrington, or provide any other
objective evidence or sound technical reasoning, establishing that increasing
power transfer to a load would necessarily maximize power transfer to the
load.
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Similarly, the Examiner asserts that because Shimada’s chopper
circuit steps up output voltage Vout to a higher voltage, “the power transfer
to the load is increase[d], [and] the power transferred to the load is
maximized.” Ans. 7. Again, however, the Examiner does not identify any
disclosure in Shimada, or provide any other objective evidence or sound
technical reasoning, establishing that increasing power transfer to a load
would necessarily maximize power transfer to the load.
Moreover, although the Examiner asserts that Shimada’s controller 8
controls output voltage Vout in response to variable reference voltage Vref1
(Ans. 7), claim 1 requires varying a reference signal so that a signal
representing power—rather than output voltage—transferred to a load is
maximized. The Examiner does not identify any disclosure in Shimada that
teaches or would have suggested varying reference voltage Vref1 so that a
signal representing power transferred to a load is maximized.
Accordingly, the Examiner does not establish that the combined
disclosures of Farrington and Shimada would have suggested a method for
transferring electric power between an electric power source and a load
using a maximum power point tracking controller that comprises controlling
switching of a control switching device of the controller based at least in part
on a reference signal, and varying the reference signal so that a signal
representing power transferred to a load is maximized, as required by claim
1. It follows that the Examiner does not establish a prima facie case of
obviousness of the subject matter recited in claim 1 within the meaning of
35 U.S.C. § 103(a). In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992)
(“[T]he examiner bears the initial burden, on review of the prior art or on
any other ground, of presenting a prima facie case of unpatentability”).
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We, therefore, do not sustain the Examiner’s rejection of claim 1, and
claim 2, which depends from claim 1, under 35 U.S.C. § 103(a) (Rejection
I). In addition, because the Examiner does not rely on any disclosure in
Melanson that cures the deficiencies of the Examiner’s reliance on
Farrington and Shimada (Final Act. 4–5), we do not sustain the Examiner’s
rejection of claim 21 under 35 U.S.C. § 103(a) (Rejection II).
CONCLUSION

Claims

35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 2 103(a) Farrington,
Shimada
1, 2
21 103(a) Farrington,
Shimada,
Melanson
21
Overall
Outcome
1, 2, 21

REVERSED