DETAILED ACTION
This office action is in response to applicant’s amendments filed on 07/06/2026.
Currently claims 1-2, 4-10, 12-17 and 23-26 are pending in the application.
Response to Arguments
Applicant’s arguments with respect to claims 1 and 9 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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 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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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.
Claims 1-2, 23 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over US 2002/0097541 A1 (Wei) and further in view of US 2020/0012304 A1 (Saha).
Regarding claim 1, Wei discloses, an apparatus (200; integrated circuit; Fig. 2; [0031] – [0035]) comprising:
a transistor (204; switch, consist of many individual transistors in parallel; Fig. 2; [0031]) having a control terminal (control input, as annotated on Fig. 2); and
a control circuit (203; amplifier; Fig. 2; [0031]) having a first input (as annotated on Fig. 2), a second input (as annotated on Fig. 2), and a control output (output of 203),
the control output coupled to the control terminal (as evident on Fig. 2), the control circuit (203) configurable to receive a first signal indicative of a first temperature (related to absolute temperature) at the first input, a second signal indicative of a second temperature (related to local temperature) at the second input, and set a state (a state at the output of OpAmp 203) of the control output responsive to a difference between the first and second temperatures (this is what an OpAmp does).
PNG
media_image1.png
553
705
media_image1.png
Greyscale
receive a first signal indicative of a first temperature at the first input, - which is the signal related to absolute temperature received at the first input of Wei’s amplifier (203; amplifier; Wei Fig. 2; [0031]–[0035]);
receive a second signal indicative of a second temperature at the second input, - which is the signal related to local temperature received at the second input of Wei’s amplifier, (203; amplifier; Wei Fig. 2; [0031]–[0035]);
set a state of the control output responsive to a difference between the first and second currents, - which is the output state of Wei’s amplifier established from the difference between its two inputs, (203; amplifier; Wei Fig. 2; [0031]);
Wei teaches, an amplifier that sets the control output responsive to the difference between its two temperature inputs, but does not expressly teach that the first and second currents are generated by a first current source and a second current source, respectively.
However, in analogous art, Saha teaches, generate, by a first current source, a first current responsive to the first signal, - in that Saha’s thermal feedback path includes a transconductance amplifier that operates as a current source and generates a current (Itherm) responsive to a temperature signal, (310/A2/M12; thermal limit circuit / transconductance amplifier generating Itherm; Saha Fig. 4; [0030]);
PNG
media_image2.png
1072
1614
media_image2.png
Greyscale
a first current responsive to the first signal, - in that the temperature signal is provided by Saha’s proportional-to-absolute-temperature (PTAT) temperature sensor, (65; PTAT temperature sensor; Saha Fig. 4; [0022]);
generate, by a second current source, a second current responsive to the second signal, - in that a second current source of the same transconductance type is applied to the second temperature signal to generate a second current, (310/A2/M12; transconductance current source; Saha Fig. 4; [0030]);
set a state of the control output responsive to a difference between the first and second currents, - in that Saha delivers the resulting current in the current domain to, and thereby sets the state of, the control terminal of the power transistor, such that with the first and second signals generated as currents, Wei’s differential control output is responsive to the difference between the first and second currents, (423; gate node of power transistor M1; Saha Fig. 4; [0030])
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, having the teachings of Wei and Saha before him/her, and generate currents by current sources, (1) because generating each temperature-dependent input as a current and modulating the power transistor’s gate drive in the current domain, as taught by Saha, provides direct and stable current-mode thermal feedback and a straightforward combination of the two temperature contributions at the control terminal; (2) since generating each current with a transconductance current source responsive to a respective temperature signal, as taught by Saha, amounts to a simple substitution of a known current-source implementation for the input stage of Wei’s amplifier, and providing a second such current source for the second temperature signal is a mere duplication of that known element (MPEP 2144.04/2144.06), so that Wei’s differential control circuit sets the control output responsive to the difference between the two currents; and (3) with a reasonable expectation of success, yielding the predictable result of a control output that sources or sinks current to the transistor control terminal in an amount and direction determined by the difference between the first and second currents. Absent this teaching in Wei, a person with ordinary skill in the art would be motivated to reach out to Saha while forming the thermal-feedback control circuit of Wei.
Regarding claim 2, Wei discloses, the apparatus of claim 1, further comprising: a group of transistors including the transistor (switch 204 consist of many individual transistors in parallel; Fig. 2; [0031]), each transistor of the group of transistors having a respective control terminal (base of a bipolar transistor or gate of a MOS transistor) coupled to the control output; and a temperature sensor (as annotated on Fig. 2) having an output coupled to the first input (as evident in Fig. 2).
Regarding claim 23, the combination of Wei and Saha discloses, the control circuit is configurable to set the control output to provide a current with a direction and an amplitude determined based on the difference between the first and second currents, - in that the output of Wei’s amplifier provides a current whose direction and amplitude depend on the difference between its two inputs, and Saha provides/sinks that current in the current domain at the transistor control terminal, (203; amplifier; Wei Fig. 2; [0031]) (423; gate node; Saha Fig. 4; [0030]);
Regarding claim 25, the combination of Wei and Saha teaches, the control circuit is configurable to cause a current to flow to the control terminal when the difference between the first and second currents has a first polarity, and to cause a current to flow from the control terminal when the difference between the first and second currents has a second polarity opposite the first polarity,- in that the output of Wei’s amplifier sources current to, or sinks current from, the control terminal according to the polarity of the difference between the two currents, and Saha expressly causes current to flow to and from the gate node of the power transistor, (203; amplifier; Wei Fig. 2; [0031]) (423; gate node of M1; Saha Fig. 4; [0030]);
Claims 9-10, 24 and 26 are rejected under 35 U.S.C. 103 as being unpatentable over US 2002/0097541 A1 (Wei) and further in view of US 2020/0012304 A1 (Saha).
Regarding claim 9, Wei discloses, an apparatus (200; integrated circuit; Fig. 2; [0031] – [0035]) comprising:
a transistor (204; switch, consist of many individual transistors in parallel; Fig. 2; [0031]) having a control terminal (control input, as annotated on Fig. 2); and
a control circuit (203; amplifier; Fig. 2; [0031]) having a first input (as annotated on Fig. 2), a second input (as annotated on Fig. 2), and a control output (output of 203),
the control output coupled to the control terminal (as evident on Fig. 2), the control circuit (203) configurable to receive a first signal indicative of a first temperature (related to absolute temperature) at the first input, a second signal indicative of a second temperature (related to local temperature) at the second input, and provide a current (current at the output of OpAmp 203, as annotated on Fig. 2) of the control output responsive to a difference between the first and second temperatures (this is what an OpAmp does).
PNG
media_image3.png
1018
1320
media_image3.png
Greyscale
receive a first signal indicative of a first temperature at the first input, - which is the signal related to absolute temperature received at the first input of Wei’s amplifier, (203; amplifier; Wei Fig. 2; [0031]–[0035]);
receive a second signal indicative of a second temperature at the second input, - which is the signal related to local temperature received at the second input of Wei’s amplifier, (203; amplifier; Wei Fig. 2; [0031]–[0035]);
provide a current at the control output based on a difference between the first and second currents, - which is the current provided at the output of Wei’s amplifier based on the difference between its two inputs, (203; amplifier; Wei Fig. 2; [0031]);
Wei teaches, an amplifier that provides a current at the control output based on the difference between its two temperature inputs, but does not expressly teach that the first and second currents are generated by a first current source and a second current source, respectively.
However, in analogous art, Saha teaches, generate, by a first current source, a first current responsive to the first signal, - in that Saha’s thermal feedback path includes a transconductance amplifier operating as a current source that generates a current (Itherm) responsive to a temperature signal from a temperature sensor, (310/A2/M12; thermal limit circuit / transconductance amplifier generating Itherm; Saha Fig. 4; [0030]) (65; PTAT temperature sensor; Saha Fig. 4; [0030]);
PNG
media_image2.png
1072
1614
media_image2.png
Greyscale
generate, by a second current source, a second current responsive to the second signal, - in that a second current source of the same transconductance type is applied to the second temperature signal, (310/A2/M12; transconductance current source; Saha Fig. 4; [0030]);
provide a current at the control output based on a difference between the first and second currents, - in that Saha provides the resulting current in the current domain to the control terminal of the power transistor, such that with the first and second signals generated as currents, the current provided at Wei’s control output is based on the difference between the first and second currents, (423; gate node of power transistor M1; Saha Fig. 4; [0030]);
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, having the teachings of Wei and Saha before him/her, and generate currents by current sources, (1) because generating each temperature-dependent input as a current and modulating the power transistor’s gate drive in the current domain, as taught by Saha, provides direct and stable current-mode thermal feedback and a straightforward combination of the two temperature contributions at the control terminal; (2) since generating each current with a transconductance current source responsive to a respective temperature signal, as taught by Saha, amounts to a simple substitution of a known current-source implementation for the input stage of Wei’s amplifier, and providing a second such current source for the second temperature signal is a mere duplication of that known element (MPEP 2144.04/2144.06), so that Wei’s differential control circuit sets the control output responsive to the difference between the two currents; and (3) with a reasonable expectation of success, yielding the predictable result of a control output that sources or sinks current to the transistor control terminal in an amount and direction determined by the difference between the first and second currents. Absent this teaching in Wei, a person with ordinary skill in the art would be motivated to reach out to Saha while forming the thermal-feedback control circuit of Wei.
Regarding claim 10, Wei discloses, the apparatus of claim 9, further comprising: a group of transistors including the transistor (switch 204 consist of many individual transistors in parallel; Fig. 2; [0031]), each transistor of the group of transistors having a respective control terminal (base of a bipolar transistor or gate of a MOS transistor) coupled to the control output; and a temperature sensor (as annotated on Fig. 2) having an output coupled to the first input (as evident in Fig. 2).
Regarding claim 24, the combination of Wei and Saha teaches, the control circuit is configurable to provide the current with a direction and an amplitude determined based on the difference between the first and second currents, - in that the output of Wei’s amplifier provides a current whose direction and amplitude depend on the difference between its two inputs, and Saha provides/sinks that current in the current domain at the transistor control terminal, (203; amplifier; Wei Fig. 2; [0031]) (423; gate node; Saha Fig. 4; [0030]).
Regarding claim 26, the combination of Wei and Saha teaches, the control circuit is configurable to cause a current to flow to the control terminal when the difference between the first and second currents has a first polarity, and to cause a current to flow from the control terminal when the difference between the first and second currents has a second polarity opposite the first polarity, - in that the output of Wei’s amplifier sources current to, or sinks current from, the control terminal according to the polarity of the difference between the two currents, and Saha expressly causes current to flow to and from the gate node of the power transistor, (203; amplifier; Wei Fig. 2; [0031]) (423; gate node of M1; Saha Fig. 4; [0030]).
Allowable Subject Matter
Claims 4-8 and 12-17 are objected to as being dependent upon rejected base claims, but would be allowable if rewritten in independent forms including all of the limitations of the base claims and any intervening claims.
Regarding claim 4, the closest prior art, US 2002/0097541 A1 (Wei), in combination with US 2020/0012304 A1 (Saha), and in combination with the other claimed features, fails to disclose, “the apparatus of claim 2, wherein: the group of transistors is a first group of transistors; the control circuit is a first control circuit, the control output is a first control output; the temperature sensor is a first temperature sensor; and the apparatus further comprises: a second control circuit having a third input, a fourth input, and a second control output a second temperature sensor having an output coupled to the third input; a second group of transistors, each transistor of the second group of transistors having a respective control terminal coupled to the second control output; and a third temperature sensor having an output coupled to the second and fourth inputs.”, in combination with the additionally claimed features, as are claimed by the Applicant.
Regarding claim 5, the closest prior art, US 2002/0097541 A1 (Wei), in combination with US 2020/0012304 A1 (Saha), and in combination with the other claimed features, fails to disclose, fails to disclose, “the apparatus of claim 1, wherein: the control circuit has first and second current terminals, the second current terminal coupled to the control output, and the control circuit includes: a resistor coupled between the first and second current terminals; a first current source coupled to the first current terminal and a control input coupled to the first input; the first current source configurable to generate the first current responsive to the first signal; and a second current source coupled to the second current terminal and a control input coupled to the second input, the second current source configurable to generate the second current responsive to the second signal”, in combination with the additionally claimed features, as are claimed by the Applicant.
Regarding claim 12, the closest prior art, US 2002/0097541 A1 (Wei), in combination with US 2020/0012304 A1 (Saha), and in combination with the other claimed features, fails to disclose, “the apparatus of claim 10, wherein: the group of transistors is a first group of transistors; the control circuit is a first control circuit, the control output is a first control output; the temperature sensor is a first temperature sensor; and the apparatus further comprises: a second control circuit having a third input, a fourth input, and a second control output a second temperature sensor having an output coupled to the third input; a second group of transistors, each transistor of the second group of transistors having a respective control terminal coupled to the second control output; and a third temperature sensor having an output coupled to the second and fourth inputs.”, in combination with the additionally claimed features, as are claimed by the Applicant.
Regarding claim 13, the closest prior art, US 2002/0097541 A1 (Wei), in combination with US 2020/0012304 A1 (Saha), and in combination with the other claimed features, fails to disclose, “the apparatus of claim 9, wherein: the control circuit has first and second current terminals, the second current terminal coupled to the control output, and the control circuit includes: a resistor coupled between the first and second current terminals; a first current source coupled to the first current terminal and a control input coupled to the first input, the first current source configurable to generate the first current responsive to the first signal; and a second current source coupled to the second current terminal and a control input coupled to the second input, the second current source configurable to generate the second current responsive to the second signal”, in combination with the additionally claimed features, as are claimed by the Applicant.
Claims 6-8 and 14-17 are also objected to due to their dependence on an objected base claim.
Examiner’s Note (Additional Prior Arts)
The examiner included a few prior arts which were not used in the rejection but are relevant to the disclosure.
US 2021/0104515 A1 (Ma) - An apparatus is disclosed including a first metal oxide semiconductor field effect transistor (MOSFET) coupled between a first input terminal for receiving a supply voltage and an output terminal for coupling to a load, and having a first gate terminal; an enable terminal coupled to the first gate terminal for receiving an enable signal; a first current mirror coupled between the first input terminal and a first terminal of a first series resistor and having an input coupled to the first gate terminal; and a second MOSFET coupled between the first gate terminal and the output terminal, and having a second gate terminal coupled to the first terminal of the first series resistor, the first series resistor having a second terminal coupled to the output terminal.
US 2018/0154784 A1 (Xu) - A vehicle powertrain is disclosed including a switch configured to provide a drive current to an electric machine and coupled with a diode array and a gate driver. The gate driver may be configured to, in response to a voltage across the array exceeding a threshold while providing the drive current in a presence of a turn-off request, confine operation of a resistive switch to a linear region to decrease a rate of change of the drive current proportional to the voltage.
US 2015/0098163 A1 (Ferrara) - A circuit is disclosed having a temperature sensing device that is coupled to a transistor. A tunable clamping circuit is connected between transistor terminals and configured to provide an adjustable clamping voltage. A temperature controller is coupled to the temperature sensing device and the tunable clamping circuit. The temperature controller is configured to trigger a change in a clamping voltage of the tunable clamping circuit based on a feedback from the temperature sensing device.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to S M SOHEL IMTIAZ whose telephone number is (408) 918-7566. The examiner can normally be reached on 8AM-5PM, M-F, PST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Christine S. Kim can be reached at 571-272-8458. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/S M SOHEL IMTIAZ/Primary Patent Examiner
Art Unit 2812
08/10/2026
Prosecution Insights