DETAILED ACTION
This Office action is in response to the application filed on 08 January 2025.
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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Rejections - 35 USC § 103
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.
Claims 1-7 are rejected under 35 U.S.C. 103 as being unpatentable over Cheng-Han Wu et. al (US20250392200A1; hereafter “Wu”) in view of Yuhei Yamaguchi et. al (US20170187278A1; hereafter “Yuhei”).
-Regarding claim 1:
Wu discloses:
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A power converter having a voltage modulated based on low-side sensed data, comprising: a high-side switch (Fig. 5; HS), wherein a first terminal of the high-side switch is coupled to an input voltage (Fig. 5; see connection between HS and VIN); a low-side switch (Fig. 5; LS), wherein a first terminal of the low-side switch is connected to a second terminal of the high-side switch (Fig. 5; see connection between HS and LS), a second terminal of the low-side switch is grounded(Fig. 5; see connection between LS and ground), a node between the first terminal of the low-side switch and the second terminal of the high-side switch is connected to a first terminal of an inductor (Fig. 5; LX into inductor L), and a second terminal of the inductor is used as an output terminal (Fig. 5; L into Vout) of the power converter; current sensing modulation circuit connected to the feedback circuit (Fig. 5; CSE connected to ERR2), configured and configured to modulate the feedback signal or a ramp voltage according to the current being sensed; a comparison circuit (Fig. 5; CMP3) connected to the feedback circuit (Fig. 5; ERR2) and configured to compare a voltage of the feedback signal with the ramp voltage to output a first comparing signal; a control circuit connected to the comparison circuit (Fig. 5; PM2 connected to CMP3) and configured to output a control signal according to the first comparing signal; and a driver circuit connected to the control circuit, a control terminal of the high-side switch and a control terminal of the low-side switch (Fig. 5; CTR connected to PM2, HS, and LS), and configured to drive the high-side switch and the low-side switch according to the control signal.
However, Wu does not disclose “a feedback circuit connected to the second terminal of the inductor” and “to sense a current that flows from the output terminal of the power converter sequentially through the inductor and the low-side switch”.
Yuhei, in the same field of endeavor, discloses:
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feedback circuit connected to the second terminal of the inductor (Fig. 1; VFB between R1 and R2 connected to error amplifier 2)……..to sense a current that flows from the output terminal of the power converter sequentially through the inductor and the low-side switch (Fig. 1; red arrows)
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device described in Wu such that a commonly used current sensing mechanism described in Yuhei is applied to a power converter having negative current control mechanism. Doing so allows for improving the control of multimode switching converter.
-Regarding claim 2:
Wu discloses:
The power converter according to claim 1, wherein the second terminal of the inductor is connected to a first terminal of an output capacitor, and a second terminal of the output capacitor is grounded (Fig. 5, right end side; L connected Cout then grounded).
-Regarding claim 3
Yuhei discloses:
The power converter according to claim 1, further comprising: a voltage divider circuit connected to the second terminal of the inductor and the feedback circuit (Fig. 1; VFB between R1 and R2 goes to error amplifier 2) and configured to divide the output voltage from the second terminal of the inductor to output a divided voltage; wherein the feedback circuit is configured to output the feedback signal according to the divided voltage.
-Regarding claim 4:
Yuhei discloses:
The power converter according to claim 1, wherein the feedback circuit includes: an error amplifier (Fig. 1; 2), wherein a first input terminal of the error amplifier is coupled to a first reference voltage (Fig. 1; reference voltage 3), a second input terminal of the error amplifier is connected to the second terminal of the inductor (Fig. 1; connection via R1, which connected to inductor L1), and an output terminal of the error amplifier is connected to an input terminal of the comparison circuit (Fig. 1; VERR into comparator 6).
-Regarding claim 5:
Yuhei discloses:
The power converter according to claim 1, wherein the current sensing modulation circuit is configured to amplify the current and modulate the feedback signal or the ramp voltage (Fig. 1; current sense and slope, Fig. 15; ramp, paragraph 0071; “The ramp circuit 9 generates and outputs a ramp voltage”) according to the current being amplified.
-Regarding claim 6:
Yuhei discloses:
The power converter according to claim 1, wherein the comparison circuit includes: a first comparator (Fig. 15; 6), wherein a first input terminal of the first comparator is connected to an output terminal of the feedback circuit (Fig. 15; VERR into a first input terminal), a second input terminal of the first comparator is coupled to the ramp voltage (Fig. 15; RAMP into a second input terminal), and an output terminal of the first comparator is connected to an input terminal of the control circuit (Fig. 15;comparator 6 into a timing control).
-Regarding claim 7:
Yuhei discloses:
The power converter according to claim 6, wherein the second input terminal of the first comparator is connected to a ramp signal generator (Fig. 15; RAMP into a second input terminal, paragraph 0071; “The ramp circuit 9 generates and outputs a ramp voltage”), and the second input terminal of the first comparator receives a ramp signal having the ramp voltage from the ramp signal generator.
Allowable Subject Matter
Claims 8-18 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.
The following is a statement of reasons for the indication of allowable subject matter:
-with respect to claim 8:
the prior arts in Wu, and Yuhei disclose the claimed invention in basic claims but do not further disclose about power receiving component between the feedback circuit and the first comparator.
-with respect to claim 13:
the prior arts in Wu, and Yuhei disclose the claimed invention in basic claims but do not further disclose about a second comparator coupled to an output voltage.
-with respect to claim 16:
the prior arts in Wu, and Yuhei disclose the claimed invention in basic claims but do not further disclose about a reference capacitor, wherein a first terminal of the reference capacitor is connected to an input terminal of the comparison circuit and an output terminal of a ramp signal generator, and a second terminal of the reference capacitor is grounded.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SEUNG HO CHOI whose telephone number is (571)272-8188. The examiner can normally be reached Monday-Thursday, 7:30 AM - 5:30 PM ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Crystal Hammond can be reached at 571-270-1682. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/SEUNG HO CHOI/Examiner, Art Unit 2838
/CRYSTAL L HAMMOND/Supervisory Primary Examiner, Art Unit 2838
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