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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Drawings
The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they include the following reference characters not mentioned in the description: “252” (Fig. 4), “M28” (Fig. 4), and “M29” (Fig. 4). Corrected drawing sheets in compliance with 37 CFR 1.121(d), or amendment to the specification to add the reference character(s) in the description in compliance with 37 CFR 1.121(b) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 5 and 6 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 5 and 6 recite the limitation "the bipolar transistor" in lines 4 and 3, respectively. There is insufficient antecedent basis for this limitation in the claims. Amending the limitation to “a bipolar transistor of the pair of bipolar transistors” is sufficient to overcome this rejection, which is how the limitation will be treated for examination purposes.
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.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Huang et al. (Patent Publication Number CN 111,182,679 A), hereafter referred to as Huang, in view of Butzmann (Patent Publication Number CN 104,167,909 A), hereafter referred to as Butzmann.
Regarding claim 1, Huang discloses:
A class D amplifier circuit (Huang, Fig. 5, 10), comprising: a class D amplifier (Fig. 5, 12), including an output section (Fig. 5, Elements Q4, Q5, C1, and 126) that includes a switching element (Fig. 5, Q4 and Q5) and outputs an output signal (Fig. 5, PWM_OUT); a current mirror circuit (Fig. 5, 113), including a pair of transistors (Fig. 5, Q2 and Q3) configured to generate an output current (Fig. 5, Idelay) according to a current flowing through the switching element (Page 10, Paragraph 1, lines 2-7); an element unit (Fig. 5, 111), including a resistive component (Fig. 5, 111) configured to generate a voltage based on the output current of the current mirror circuit (Fig. 5, consider voltage at non-grounded end of resistor 111, see also Page 8, Paragraph 4, lines 16-23); and a comparator (Fig. 5, see comparator “OP”), configured to compare the voltage generated by the element unit with a reference voltage (Fig. 5, see connection between 111 and OP and between Vref and OP), wherein the element unit is configured such that the resistive component compensates for a temperature characteristic of the current flowing through the switching element (Page 9, Paragraph 2, lines 13-26), but fails to disclose [the current mirror circuit including a pair of] bipolar [transistors].
However, Butzmann teaches [the current mirror circuit including a pair of] bipolar [transistors] (Butzmann, Paragraph 8, lines 8-11).
Huang and Butzmann are both considered to be analogous to the claimed invention because they are in the same field of improving class D amplifiers. Therefore, it would have been obvious to one of ordinary skill in the art to replace the MOSFET transistor current mirror of Huang with a bipolar transistor current mirror, which would have the effect of providing a well-known equivalent implementation of the circuit of Huang (Butzmann, Paragraph 8, lines 8-11).
Claims 2-3 and 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over Huang in view of Butzmann as applied to claim 1 above, and further in view of Sean et al. (Patent Number US 6,677,808 B1), hereafter referred to as Sean.
Regarding claim 2, Huang further discloses:
further comprising: when the element unit is set to be a first element unit (Huang, Fig. 5, 111), but fails to disclose a reference generation unit including a second element unit having a resistive component, wherein the reference generation unit is configured to generate the reference voltage by passing a current through the second element unit, and a sign of a temperature characteristic of the resistive component of the first element unit is same as a sign of a temperature characteristic of the resistive component of the second element unit.
However, Sean teaches a reference generation unit (Sean, Fig. 1, VREF2 and R6) including a second element unit (Fig. 1, R6) having a resistive component (Fig. 1, R6), wherein the reference generation unit is configured to generate the reference voltage by passing a current through the second element unit (Fig. 1, consider current I3 through resistor R6), and a sign of a temperature characteristic of the resistive component of the first element unit is same as a sign of a temperature characteristic of the resistive component of the second element unit (consider that element 111 of Huang, Fig. 5 and R6 are both resistors, and therefore would have similar temperature characteristics).
Huang, Butzmann, and Sean are all considered to be analogous to the claimed invention because they are in the same field of improving CMOS amplifier circuits. Therefore, it would have been obvious to one of ordinary skill in the art to include the reference voltage generation circuit of Sean in the circuit of Huang, which would have the effect of providing a well-known voltage generation circuit to implement the reference voltage of Huang (Sean, Col. 4, lines 35-41).
Regarding claim 3, Huang and Butzmann fail to disclose:
wherein a slope of the temperature characteristic of the resistive component of the first element unit is same as a slope of the temperature characteristic of the resistive component of the second element unit.
However, Sean further teaches wherein a slope of the temperature characteristic of the resistive component of the first element unit is same as a slope of the temperature characteristic of the resistive component of the second element unit (consider that element 111 of Huang, Fig. 5 and R6 are both resistors, and therefore would have similar temperature characteristics).
Huang, Butzmann, and Sean are all considered to be analogous to the claimed invention because they are in the same field of improving CMOS amplifier circuits. Therefore, it would have been obvious to one of ordinary skill in the art to include the reference voltage generation circuit of Sean in the circuit of Huang, which would have the effect of providing a well-known voltage generation circuit to implement the reference voltage of Huang (Sean, Col. 4, lines 35-41).
Regarding claim 5, Huang further discloses:
wherein the switching element includes a MOSFET (Huang, Fig. 5, consider that Q4 and Q5 are both MOSFETs), but fails to disclose and a sign of a temperature characteristic of an on-resistance of the MOSFET is same as a sign of a temperature characteristic of a thermal voltage of the bipolar transistor.
However, Sean teaches and a sign of a temperature characteristic of an on-resistance of the MOSFET is same as a sign of a temperature characteristic of a thermal voltage of the bipolar transistor (Sean, Col. 1, lines 20-22).
Huang, Butzmann, and Sean are all considered to be analogous to the claimed invention because they are in the same field of improving CMOS amplifier circuits. Therefore, it would have been obvious to one of ordinary skill in the art to include the bipolar transistor temperature characteristic of Sean in the circuit of Huang, which would have the effect of providing an accurate circuit model for the circuit of Huang (Sean, Col. 1, lines 20-22).
Regarding claim 6, Huang and Butzmann fail to disclose:
wherein a slope of the temperature characteristic of the on-resistance of the MOSFET is same as a slope of the temperature characteristic of the thermal voltage of the bipolar transistor.
However, Sean further teaches wherein a slope of the temperature characteristic of the on-resistance of the MOSFET is same as a slope of the temperature characteristic of the thermal voltage of the bipolar transistor (Sean, Col. 1, lines 20-29).
Huang, Butzmann, and Sean are all considered to be analogous to the claimed invention because they are in the same field of improving CMOS amplifier circuits. Therefore, it would have been obvious to one of ordinary skill in the art to make the temperature characteristics of the MOSFET of Huang and the bipolar transistor of Butzmann be the same, which would have the effect of increasing circuit stability (Sean, Col. 1, lines 25-29).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Huang in view of Butzmann and Sean as applied to claim 2 above, and further in view of Nielsen (Patent Publication Number US 2010/0033247 A1), hereafter referred to as Nielsen.
Regarding claim 4, Huang, Butzmann, and Sean fail to disclose:
wherein the second element unit includes a metal-oxide-semiconductor field-effect transistor (MOSFET), and the reference generation unit is configured to generate the reference voltage based on a voltage generated by an on-resistance of the MOSFET.
However, Nielsen teaches wherein the second element unit includes a metal-oxide-semiconductor field-effect transistor (MOSFET) (Nielsen, Paragraph 43, lines 1-5), and the reference generation unit is configured to generate the reference voltage based on a voltage generated by an on-resistance of the MOSFET (Paragraph 43, lines 1-7).
Huang, Butzmann, Sean, and Nielsen are all considered to be analogous to the claimed invention because they are in the same field of improving CMOS amplifier circuits. Therefore, it would have been obvious to one of ordinary skill in the art to use MOSFET transistors to implement the reference generation unit of Sean, which would have the effect of providing a well-known implementation of a controllable resistor to set the reference voltage of Huang (Nielsen, Paragraph 43, lines 1-7).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Splithof et al. (Patent Publication Number US 2024/0329099 A1) discloses (Fig. 1H) a class D amplifier including a comparator circuit.
Fiedler et al. (Patent Publication Number US 2026/0058610 A1) discloses (Fig. 9B) a class D amplifier including a current mirror circuit.
Dasgupta et al. (Patent Number US 6,583,667 B1) discloses a CMOS amplifier with temperature compensation control.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Lance T Bartol whose telephone number is (703)756-1267. The examiner can normally be reached Monday - Thursday 6:30 a.m. - 4:00 p.m. CT, Alternating Fridays 6:30 - 3:00.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Andrea Lindgren Baltzell can be reached at 571-272-5918. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/LANCE TORBJORN BARTOL/Examiner, Art Unit 2843
/ANDREA LINDGREN BALTZELL/Supervisory Patent Examiner, Art Unit 2843
Prosecution Insights