Prosecution Insights
Last updated: April 19, 2026
Application No. 18/231,887

SYSTEMS AND METHODS FOR DC-DC POWER CONVERTER TOPOLOGIES

Final Rejection §103
Filed
Aug 09, 2023
Examiner
TRAN, NGUYEN
Art Unit
2838
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Mcmaster University
OA Round
2 (Final)
83%
Grant Probability
Favorable
3-4
OA Rounds
2y 6m
To Grant
91%
With Interview

Examiner Intelligence

Grants 83% — above average
83%
Career Allow Rate
895 granted / 1073 resolved
+15.4% vs TC avg
Moderate +8% lift
Without
With
+7.6%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
36 currently pending
Career history
1109
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
51.6%
+11.6% vs TC avg
§102
33.9%
-6.1% vs TC avg
§112
10.7%
-29.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1073 resolved cases

Office Action

§103
DETAILED ACTION 1. This action is in response to the amendment filed on 2/2/26. Notice of Pre-AIA or AIA Status 2. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Response to Arguments 3. Applicant’s arguments with respect to claim(s) 1 have been considered but are moot because the new ground of rejection. Claim Rejections - 35 USC § 103 4. 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. 5. Claims 1, 5-6, 8, and 20-24 are rejected under 35 U.S.C. 103 as being unpatentable over Ammanamanchi et al. (US 20230378795) in view of Zhu et al. (US 20210408889) and Dai et al. (US 20200412237). Regarding claim 1: Ammanamanchi et al. disclose a direct current (DC)-DC power converter (i.e. figures 4-9) comprising: a primary sub-circuit (i.e. 210) coupled to a fixed or variable DC input voltage (i.e. DC input to 120); a first secondary sub-circuit (i.e. 220) and a second secondary sub-circuit (i.e. 230); a transformer (i.e. 240) isolating the primary sub-circuit (i.e. 210) from the first and the second secondary sub-circuits (i.e. 220) (i.e. 230), the transformer (i.e. 240) comprising a predetermined number of turns (i.e. turns of 240); the first and the second secondary sub-circuits (i.e. 230) (i.e. 240) being configurable in either a series mode (i.e. figure 6: series configuration) or a parallel mode (i.e. figure 5: parallel configuration) by changing a configuration of one or more of a first, second and third transition switch (i.e. 200, 202, 203) (i.e. ¶ 62); and the first and the second secondary sub-circuits (i.e. 220) (i.e. 230) providing an output charging voltage (i.e. output voltage) and an output charging current (i.e. output current) for charging an external device (i.e. battery), but does not specifically disclose the primary sub-circuit comprising a three-level (3-L) neutral-point diode claimed multilevel bridge circuit; and a share magnetic core. Zhu et al. disclose a power converter (i.e. figure 3A) comprising the primary sub-circuit comprising a three-level (3-L) neutral-point diode claimed multilevel bridge circuit (i.e. 310). Dai et al. disclose a power conversion (i.e. figure 4) comprising a share magnetic core (i.e. core of 191). Therefore, it would have been obvious to one with ordinary skill in the art before the earliest effective filing date to modify the circuit of Ammanamanchi et al.’s invention with the converter as disclose by Dai et al. to achieve high-efficiency power conversion system. Regarding claim 5: (i.e. figures 4-9) wherein each of the first and second secondary sub-circuits (i.e. 220) (i.e. 230) comprise a full-bridge switching circuit. Regarding claim 6: (i.e. figures 4-9) wherein the primary sub-circuit further comprises a resonant inductor (i.e. Lr1) and a resonant capacitor (i.e. Cr1). Regarding claim 20: (i.e. figures 4-9) wherein the external device is an electric vehicle (i.e. battery of a vehicles). Regarding claim 21: (i.e. figures 4-9) wherein each of the first and second secondary sub-circuits (i.e. 220) (i.e. 230) further comprise a capacitor (i.e. Cr2, Cr2), an inductor (i.e. Lr2, Lr2) and an output capacitor (i.e. C01, C02). Regarding claim 22: (i.e. figures 4-9) wherein in a parallel mode, the first transition switch and the second transition switch (i.e. 200, 202, 203) are closed and the third transition switch is open (i.e. see configuration of figures 5-6) (i.e. ¶ 62). Regarding claim 23: (i.e. figures 4-9) wherein in a series mode (i.e. figure 6: series configuration), the first transition switch and the second transition switch are open and the third transition switch is closed (i.e. see configuration of figures 5-6) (i.e. ¶ 62). Regarding claim 24: (i.e. figures 4-9) wherein the converter operates in one of a boosting mode, a bucking mode and a unity gain mode (i.e. function of figure 4). 6. Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Ammanamanchi et al. (US 20230378795) in view of Zhu et al. (US 20210408889) and Dai et al. (US 20200412237) and further in view of Itoh et al. (US 10171004). Regarding claim 7: Ammanamanchi et al. disclose the limitation of the claim(s) as discussed above, but does not specifically disclose the primary sub-circuit further comprises two flying capacitors. Tange discloses a power supply (i.e. figure 1) comprising the primary sub-circuit further comprises two flying capacitors (i.e. cf1, cf2). Therefore, it would have been obvious to one with ordinary skill in the art before the earliest effective filing date to modify the circuit of Ammanamanchi et al.’s invention with the power supply as disclose by Tange to operate with high efficiency even when the variation range of a load is wide. Conclusion 7. Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. 8. Any inquiry concerning this communication or earlier communications from the examiner should be directed to NGUYEN TRAN whose telephone number is (571)270-1269. The examiner can normally be reached Flex: M-F 8-7. 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, Monica Lewis can be reached at 571-272-1838. 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. /Nguyen Tran/Primary Examiner, Art Unit 2838
Read full office action

Prosecution Timeline

Aug 09, 2023
Application Filed
Oct 01, 2025
Non-Final Rejection — §103
Feb 02, 2026
Response Filed
Feb 23, 2026
Final Rejection — §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
83%
Grant Probability
91%
With Interview (+7.6%)
2y 6m
Median Time to Grant
Moderate
PTA Risk
Based on 1073 resolved cases by this examiner. Grant probability derived from career allow rate.

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