DETAILED ACTION
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 .
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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-2 & 5-8 are rejected under 35 U.S.C. 102(a)(1) & (a)(2) as being anticipated by Xu (U.S. PGPub # 2016/0322900).
Regarding Independent claim 1, Xu teaches:
A zero current detection circuit (Title, Abstract, & paragraphs 0002, 0006-0008.) comprising:
a first comparator (Fig 1 Element 103. Paragraph 0024.) configured to compare a first voltage (Fig 1 Elements 103 & IL. Paragraph 0024.), representative of a first current (Fig 1 Elements 103 & IL. Paragraph 0024.), with a first threshold voltage (Fig 1 Elements 103 & Voffset. Paragraphs 0024.); and
a calibration circuit (Fig. 1 Elements 101 & 102. See paragraphs 0022-0025.) configured to modify the value of the first threshold voltage in view of process (Fig. 1 Elements 101 & 102. See paragraphs 0022-0025.), voltage (Fig. 1 Elements 101 & 102. See paragraphs 0022-0025.), and/or temperature variations.
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Regarding claim 2, Xu teaches all elements of claim 1, upon which this claim depends.
Xu teaches said first threshold voltage is an offset voltage of said first comparator (See Fig. 4 See paragraphs 0023-0025, 0027-0029, & 0031-0032.).
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Regarding claim 5, Xu teaches all elements of claim 1, upon which this claim depends.
Xu teaches a logic circuit configured to be the main control circuit of the zero current detection circuit (Fig. 1 Element 204, the logic circuit. Fig. 4 Element 204, the logic circuit. Paragraphs 0022, 0024-0025, 0027, 0029, & 0032-0033 wherein the logic circuits are disclosed.).
Regarding claim 6, Xu teaches all elements of claim 1, upon which this claim depends.
Xu teaches a DC-DC converter comprising a zero current detection circuit according to claim 1 (Paragraphs 0003, 0022, & 0050 wherein the disclosed Buck convertor is a DC-DC converter.).
Regarding claim 7, Xu teaches all elements of claim 6, upon which this claim depends.
Xu teaches two switches coupled in series, and a coil having one of its terminals coupled to the middle node between said two switches (Fig. 5 Elements M1, M2, SW, & L1.).
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Regarding claim 8, Xu teaches all elements of claim 7, upon which this claim depends.
Xu teaches said zero current detection circuit is configured to detect when the current in said coil is equal to zero (Title, Abstract, & Paragraphs 0003, 0006, 0008, 0024, & elsewhere.).
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim 3-4 are rejected under 35 U.S.C. 103 as being unpatentable over Xu (U.S. PGPub # 2016/0322900) in view of Chen et al (U.S. PGPub # 2014/0111168).
Regarding claim 3, Xu teaches all elements of claim 1, upon which this claim depends.
Xu does not explicitly teach said calibration circuit comprises a second comparator circuit.
Chen teaches said calibration circuit comprises a second comparator circuit (Fig. 7 Element 213, the CMP, and comparator 215. See paragraphs 0022-0026.).
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It would have been obvious to one of ordinary skill in the art before the effective time of filing to apply the teachings of Chen to the teachings of Xu such that said calibration circuit comprises a second comparator circuit because this would allow one to better control the functioning of the down bridge transistor.
Regarding claim 4, Xu teaches all elements of claim 1, upon which this claim depends.
Xu does not explicitly teach said second comparator circuit is more precise than the first comparator.
Chen teaches said second comparator circuit is more precise than the first comparator (Fig. 7 Element 213 in relation to 215. See paragraphs 0022-0026.).
It would have been obvious to one of ordinary skill in the art before the effective time of filing to apply the teachings of Chen to the teachings of Xu such that said second comparator circuit is more precise than the first comparator because this would allow one to better control the functioning of the down bridge transistor.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. The prior art listed but not cited represents the previous state of the art and analogous art that teaches some of the limitations claimed by applicant.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER P MCANDREW whose telephone number is (469)295-9025. The examiner can normally be reached Monday-Thursday 6-4:30.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Lee Rodak can be reached on 571-270-5628. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CHRISTOPHER P MCANDREW/Primary Examiner, Art Unit 2858
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