15445926 - (D) (P.T.A.B. Apr. 1, 2020)

Linear Technology LLC

Patent Trials and Appeals BoardApr 1, 2020

15445926 - (D) (P.T.A.B. Apr. 1, 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. 15/445,926 02/28/2017 Barry Harvey ADIRE.282A 8340 110833 7590 04/01/2020 KNOBBE, MARTENS, OLSON & BEAR, LLP (ADIRE/ADINC/ADHIT) 2040 Main Street, Fourteenth Floor Irvine, CA 92614 EXAMINER KIM, JUNG H ART UNIT PAPER NUMBER 2842 NOTIFICATION DATE DELIVERY MODE 04/01/2020 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): efiling@knobbe.com jayna.cartee@knobbe.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte BARRY HARVEY Appeal 2019–003678 Application 15/445,926 Technology Center 2800 Before BEVERLY A. FRANKLIN, CHRISTOPHER C. KENNEDY, and JULIA HEANEY, Administrative Patent Judges. FRANKLIN, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1–6, 8, and 9. We have jurisdiction under 35 U.S.C. § 6(b). We REVERSE. 1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R. § 1.42(a). Appellant identifies the real party in interest as Linear Technology LLC. Appeal Br. 3. Appeal 2019-003678 Application 15/445,926 2 CLAIMED SUBJECT MATTER Claim 1 is illustrative of Appellant’s subject matter on appeal and is set forth below (with text in bold for emphasis): 1. A charge pump, comprising: a flying capacitor coupled between a drive node and an output; a first drive switch coupled between a first supply and the drive node and operative to charge the flying capacitor; a second drive switch coupled between a second supply and the drive node and operative to discharge the flying capacitor; a third switch coupled between the first supply and the drive node and operative to pre-charge the drive node; and a fourth switch coupled between the second supply and the drive node and operative to pre-discharge the drive node, wherein a slew rate of the third switch is slower than a slew rate of the first switch. REFERENCES The prior art relied upon by the Examiner is: Name Reference Date Ojiro US 7,368,952 B2 May 6, 2008 Tsukada US 8,879,312 B2 Nov. 4, 2014 THE REJECTION Claims 1–6, 8, and 9 are rejected under 35 U.S.C. § 103 as being unpatentable over Tsukada in view of Ojiro. Final Act. 3. Appeal 2019-003678 Application 15/445,926 3 OPINION The dispositive issue in this case is whether the applied art teaches the claimed subject matter, and in particular, the claimed element of “wherein a slew rate of the third switch is slower than a slew rate of the first switch.” The Examiner admits that the primary reference of Tsukada does not teach this claim element (as well as other elements). Final Act. 3. The Examiner relies upon the secondary reference of Ojiro for teaching this claim element. Final Act. 4. Appellant argues, inter alia, that the applied art does not teach this claim element. Appeal Br. 9–11. Appellant explains how the Examiner’s reliance on Ojiro for teaching this claim element is flawed. Appeal Br. 10. Appellant explains that transistor P2, shown in Ojiro’s Figure 4 (asserted by the Examiner to correspond to the claimed first switch) is driven by a smaller driver 3, thereby resulting in a slower transition time, represented by waveform L2 shown in Figure 5A of Ojiro. Appeal Br. 10. Appellant also argues that Ojiro’s transistor P1, shown in Ojiro’s Figure 4 (asserted by the Examiner to correspond to the third switch) is driven by a larger driver 1 (shown in Ojiro’s Figure 4), thereby resulting in a faster transition time, represented by waveform L1 in Ojiro’s Figure 5A. Id. Appellant therefore submits that even if transistor P2 may be larger than transistor P1, transistor P2 is driven by a smaller driver 3, thereby resulting in a slower slew rate for transistor P2 than for transistor P1 (P1 being operated by a larger driver 1). Appeal Br. 10. In response, the Examiner maintains that the slew rate of P1 compared to P2 is slower since P1 is smaller than P2 for the reasons presented on page Appeal 2019-003678 Application 15/445,926 4 4 of the Answer. The Examiner refers to Appellant’s Specification in support thereof. Ans 4–5. In reply, Appellant disputes the Examiner’s stated response. Reply Br. 6–7. Appellant argues that when a transistor is weakly turned on, it conducts less current than when fully turned on, much like how the rate of water flowing through a faucet depends on the degree to which the faucet is turned on. Reply Br. 6. Appellant explains that a smaller transistor turned on strongly can conduct more current than a larger transistor turned on weakly.2 Appellant further explains that this is supported by Ojiro’s Figure 5A, whereby the degree to which transistor P2 is turned on is graphically represented by the amount that line L2 is below the turn-on threshold Vth, at a given point in time. Similarly, the degree to which transistor P1 is turned on is graphically represented by the amount that line L1 is below Vth. Reply Br. 6. Appellant explains that as shown in Ojiro’s Figure 5A, in contrast to transistor P1, which is quickly turned on to full strength, transistor P2 is more weakly turned-on than transistor P1 over the full duration that OUT is transitioning and the circuit is slewing. Reply Br. 6. As such, Appellant submits that therefore Ojiro does not disclose or suggest “a slew rate of the 2 As evidence of this, Appellant refers to col. 5, ll. 43–49 of US 9,184,623 to Cical et al., cited in the IDS dated 8/3/2017 (therein it is disclosed that “transistor drive strength is determined by the size of the transistor multiplied by the square of the difference of gate-to-source voltage (Vgs) and the threshold voltage (Vt) of the transistor. However, a larger Vgs on the transistors 252 and 254 compensates for their smaller size and allows them to overpower the larger charging transistor 206”). Reply Br. 6. Appeal 2019-003678 Application 15/445,926 5 third switch is slower than a slew rate of the first switch,” as recited in Claim 1. On pages 6–7 of the Reply Brief, Appellant also addresses the Examiner’s reliance upon the Specification, with reference to paragraph [0032] of the Specification. We are persuaded by the aforementioned arguments presented by Appellant because the preponderance of evidence, as discussed by Appellant throughout the record, supports Appellant’s position. We thus reverse the Examiner’s decision to reject the appealed claims for the reasons provided by Appellant in the record. CONCLUSION We reverse the Examiner’s decision. DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Reversed Affirmed 1–6, 8, 9 103 Tsukada, Ojiro 1–6, 8, 9 REVERSED