DETAILED ACTION
This Office action is in response to the application filed on 21 March 2024.
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 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over Tatsuya Hisada (JP 2022136418A; hereafter “Hisada”), in view of Al-Qutayri (IEEE Xplore DOI: 10.1109/ASIC.1997.616974 ; hereafter “Al”), Behnam Samadpoor Rikan (IEEE Xplore DOI: 10.1109/ISOCC.2018.8649947; hereafter “Rikan”).
-regarding Claim 1:
Hisada discloses:
A current limiting circuit for limiting an upper limit of an output current to a predetermined value, the current limiting circuit comprising: a an auxiliary power supply circuit (Figs. 2 and 8) to which a second voltage higher than the first voltage is supplied and which supplies a second current to the output terminal to suppress an increase in the first current when the first current exceeds a threshold current, based on the monitor voltage, wherein the auxiliary power supply circuit includes a control voltage generation circuit (Figs. 2 and 8; [bGNR part) that generates a control voltage that decreases as the monitor voltage increases,a current generation circuit (Right half side in Figs. 2 and 8 with additional LPF part) that outputs an auxiliary current for generating the second current, based on a differential voltage between the second voltage and the control voltage.
Hisada discloses the control voltage generation circuit and the current generation circuit in his overcurrent protection circuit and taught the design of the auxiliary power supply circuit in claim 1.
However, Hisada does not disclose the current monitor circuit, the threshold voltage generation circuit, and the limiting circuit.
Al discloses:
a current monitor circuit that outputs a monitor voltage (Fig.1 VDD) according to a first current (Fig.1 CUT) generated by a first voltage and supplied to an output terminal;
Al discloses a prototype supply current monitor for testing analogue circuits and taught the design of the current monitor circuit in claim 1.
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Rikan discloses:
a threshold voltage generation circuit (blue arrow in Fig. R) that generates a threshold voltage according to an upper limit value of the second current, a limiting circuit (red arrow in Fig. R) that limits a lower limit value of the control voltage to the threshold voltage;
Rikan discloses a block diagram of the proposed reference voltage generator (Fig. R) based on threshold voltage difference of low threshold voltage and standard threshold voltage transistors devices. The structure design is intended to apply the difference between the threshold voltages to produce a stable reference voltage. Rikan taught the design of the threshold voltage generation circuit and the limiting circuit in claim 1.
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 Hisada such that a commonly used current monitor configuration as taught by Al, and the threshold voltage generation circuit and the limiting circuit as taught by Rikan are added into the auxiliary power supply circuit. Doing so allows for providing a monitor voltage according to a first current generated by a first voltage, and producing a stable reference voltage by applying the difference between the threshold voltages.
-regarding Claim 2:
Hisada discloses:
The current limiting circuit according to claim 1, the control voltage generation circuit includes a first differential amplifier (AMP in Fig 2) that has a positive input terminal to which the monitor voltage is input and a negative input terminal to which an upper limit voltage corresponding to the threshold current is input, and outputs a differential voltage between the monitor voltage and the upper limit voltage, a first transistor (N1 in Fig 2) having a control electrode to which the differential voltage is input, a second transistor (P1 in Fig 2) having a first main electrode to which the second voltage is input and a second main electrode to which a first main electrode of the first transistor is connected, and a resistor (R0 in Fig 2) whose first end is connected to a second main electrode of the first transistor and whose second end is connected to a ground, wherein the control voltage is output from a connection point between the first transistor(N1 in Fig 2) and the second transistor(P1 in Fig 2).
-regarding Claim 3:
Rikan discloses:
The current limiting circuit according to claim 2, the threshold voltage generation circuit includes a third transistor (M1 in Fig. R) having a first main electrode to which the second voltage is input, and a variable constant current source whose first end is connected to a second main electrode of the third transistor and whose second end is connected to the ground, wherein the threshold voltage (VA in Fig. R) is output from a connection point between the third transistor (M1 in Fig. R) and the variable constant current source (I in Fig. R).
-regarding claim 4:
Rikan discloses:
The current limiting circuit according to claim 3, the limiting circuit includes a fourth transistor (M2 in Fig. R) having a first main electrode connected to the second voltage and a second main electrode connected to the connection point between the first transistor and the second transistor, and a third differential amplifier (Fig. R) having a negative input terminal to which the control voltage is input, a positive input terminal to which the threshold voltage (VA in Fig. R) is input, and an output terminal connected to a control electrode of the fourth transistor (M2 in Fig. R).
Allowable Subject Matter
Claims 5 and 6 would be allowable if rewritten in independent form including all of the limitations of the base claims.
The following is a statement of reasons for the indication of allowable subject matter:
-with respect to claim 5, the closest prior arts in Hisada discloses the invention according to claim 1, which is an independent claim of claim 5, but does not further disclose about the switching power supply.
-with respect to claim 6, the closest prior arts in Hisada discloses the invention according to claim 1, which is an independent claim of claim 6, but does not further disclose about a rectifier circuit.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
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/SEUNG HO CHOI/Examiner, Art Unit 2838 /CRYSTAL L HAMMOND/Supervisory Primary Examiner, Art Unit 2838