DETAILED ACTION
This Office action is in response to the amendment filed on 07 January 2026.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Response to Arguments
The filed amendments and accompanying remarks are sufficient to overcome the rejection of claims 1-4, 6, 8-13 and 15 under 35 USC 102 over US 2020/0119642 (“Zhang”). That is, Zhang does not disclose introducing PFM hysteresis into a convertor loop of the buck converter by a sudden change in a peak of the inductor current by enabling and disabling slope compensation.
However, Applicant's arguments with respect to the rejection of claims 1, 11 and 13 under 35 U.S.C. 102 over US 2015/0028830 (“D1”) have been fully considered but they are not persuasive.
Regarding the rejections over D1, Applicant merely quotes the amended portions of claims 1 and 13 and states that, “D1 fails to disclose these features” (Remarks at p. 10) without further explanation. The arguments fail to comply with 37 CFR 1.111(b) because they amount to a general allegation that the claims define a patentable invention without specifically pointing out how the language of the claims patentably distinguishes them from the references. See the rejection of claims 1, 11 and 13 as being anticipated by D1, below.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1, 11, and 13 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US2015/0028830 (hereinafter “D1”).
In re claims 1 and 11,
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542
689
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In re claim 13,
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392
712
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In addition to the above and with respect to the amended portions of each of claims 1, 11 and 13, D1 also discloses introducing PFM transition hysteresis into a convertor loop of the buck converter by a sudden change in a peak of the inductor current by enabling and disabling slope compensation as follows:
In D1, paragraph 32 teaches the generation of sleep-trigger signal SLE by comparator COP2 based on the current operation mode (i.e., PWM or PFM), “so as to enable or disable … the slope compensating circuit 240”. This teaching is understood to indicate introduction of hysteresis by enabling and disabling the slope compensation.
Such interpretation of D1’s disclosure is further corroborated by paragraph 34, teaching that the switching between PWM and PFM is done in a manner, “so as to reduce oscillation of the current-mode buck converter 200 switched between the PWM mode and the PFM mode,” which is understood to refer to a hysteresis effect which is known by the ordinary artisan to be intended to prevent or reduce the “chattering” effect, that is, the undesirable, rapid switching back and forth between operation modes.
Finally, regarding the recitation, “disable or greatly reduce a slope compensation”: this recites two possible limitations in the alternative. Only at least one of the possibilities need be taught in the prior art to show anticipation of the claim as a whole. Nonetheless, D1 teaches disabling the slope compensation in PFM mode, which is understood to also cover “greatly reducing” the slope compensation, as disabling can be considered to correspond to the special case of reducing the slope compensation to zero. Such reduction is considered “great” because it represents the maximum amount of reduction of the slope compensation that can be performed at any given time.
Allowable Subject Matter
Claims 2-10, 12 and 14-16 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
With respect to claim 2, the closest prior art in D1 discloses the invention according to claim 1 as explained above, and further discloses an inductor (Fig. 2: shown but not labeled), but does not disclose wherein the PCM buck converter is arranged to increase the peak in an inductor current through the inductor by disabling or greatly reducing the slope compensation when detecting the entering of the PFM, and wherein the PCM buck converter is arranged to decrease the peak in the inductor current through the inductor by enabling the slope compensation when detecting the exiting of the PFM. Furthermore, the additional prior art on record does not suggest an obvious modification to D1 that would result in the solution as recited in claim 2.
Claims 3-7 and 9-10 each depend, either directly or indirectly, on claim 2 and so would be allowable for the same reasons as explained above, mutatis mutandis.
With respect to claim 8, the closest prior art in D1 discloses the invention according to claim 1 as explained above, but does not disclose a switching regulator comprising one or more PCM buck converters according to claim 1. Furthermore, the additional prior art on record does not suggest an obvious modification to D1 that would result in the solution as recited in claim 8.
With respect to claim 12, the closest prior art in D1 discloses the invention according to claim 11 as explained above, but does not disclose wherein the slope compensation element is arranged to be triggered by a PFM activation signal (PFM_ACT) from a PFM comparator to enable or disable the slope compensation. Furthermore, the additional prior art on record does not suggest an obvious modification to D1 that would result in the solution as recited in claim 12.
With respect to claim 14, the closest prior art in D1 discloses the invention according to claim 13 as explained above, but does not disclose wherein the clamp circuit comprises a clamp amplifier arranged to receive the VCOMP from the EA and arranged to regulate the VCOMP to a reference voltage for PFM (VREF_PFM), and wherein the clamp circuit comprises one or more transistors arranged to gain up the VREF_PFM to obtain the PFM_DET. Furthermore, the additional prior art on record does not suggest an obvious modification to D1 that would result in the solution as recited in claim 14.
Claim 16 depends from claim 14 and so would be allowable for the same reasons as explained above, mutatis mutandis.
With respect to claim 15, the closest prior art in D1 discloses the invention according to claim 13 as explained above, but does not disclose wherein the clamp circuit is further arranged to generate a signal to a converter oscillator for PFM frequency fold back. Furthermore, the additional prior art on record does not suggest an obvious modification to D1 that would result in the solution as recited in claim 15.
Conclusion
THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/FRED E FINCH III/Primary Examiner, Art Unit 2838