Prosecution Insights
Last updated: April 19, 2026
Application No. 17/205,017

CONSTANT CURRENT CHARGING DEVICE

Final Rejection §103
Filed
Mar 18, 2021
Examiner
JEPPSON, PAMELA J
Art Unit
2859
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Silicon Integrated Systems Corp.
OA Round
5 (Final)
66%
Grant Probability
Favorable
6-7
OA Rounds
3y 4m
To Grant
88%
With Interview

Examiner Intelligence

Grants 66% — above average
66%
Career Allow Rate
65 granted / 98 resolved
-1.7% vs TC avg
Strong +21% interview lift
Without
With
+21.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
60 currently pending
Career history
158
Total Applications
across all art units

Statute-Specific Performance

§101
3.3%
-36.7% vs TC avg
§103
55.8%
+15.8% vs TC avg
§102
15.8%
-24.2% vs TC avg
§112
21.4%
-18.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 98 resolved cases

Office Action

§103
DETAILED ACTION Status of the Claims In the communication dated November 6, 2025, claims 1-3, 5-7 and 10-12 are pending. Claims 1 and 11-12 are amended, claims 4 and 8-9 are previously cancelled. Response to Arguments The applicant argues that Lai does not teach that the charging current is adjusted according to the charging (regulating?) current, arguing that Lai teaches that an offset voltage of the amplifiers is recorded and stored by introducing a switched capacitor circuit and the offset voltage is released during the sampling process, ensuring a sampling accuracy of the charging current and solving a problem of instability and easy failure of the constant current charging loop during high current charging due to the sampling error (see page 8 of applicant arguments). The applicants arguments and amendments have been fully considered and are, in part, persuasive, however, the reference of Lai is still applicable to the rejection, as detailed in the rejection below. In summary of the rejection, element 6 of Lai is designated as a charging current adjusting unit 6, thus, being a current regulating unit that outputs control of the current signal to the transistors MN1/MN2, which, in turn, control the charging of the battery (BAT). Thus, although the rejection is adjusted, the Examiner maintains the validity of Lai. 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 1-3 and 5-7 are rejected under 35 U.S.C. 103 as being unpatentable over Lai et al. CN107482722A in view of Allgaier et al. US20130106358A1 as evidenced by Bostrom US20160352293A1. Regarding claim 1, Lai teaches a constant current charging device (page 2, first paragraph and FIG. 8), configured to charge a device to be charged (BATT). Lai discloses a current regulating unit (6) electrically coupled to the device to be charged (BAT) and configured to provide a regulating current (from charging current regulating unit 6) and a charging current (provided to the battery BAT) according to a reference voltage (REF to amplifier A3) wherein the charging current is adjusted according to the regulating current (page 5 - ¶5 - charging current regulating unit compares the sampling voltage with the reference voltage REF to obtain a charging current regulating signal which is fed back to the gate terminal of the first transistor MN1 for controlling and regulating the magnitude of the constant charging current- thus the charging current is adjusted according to the regulating current). Lai discloses a current-to-voltage converting unit (5) electrically coupled to the current regulating unit (6). Lai discloses a first operational amplifier (A1) electrically coupled to the current regulating unit (6), the current-to-voltage converting unit (5), and the device to be charged (BAT) (adjust the voltage PUMP at the gate of the power transistor so as to control the charging current at a constant value; page 1; ¶3). the current regulating unit (6) comprises: a first transistor (MN2) comprising a first control terminal, a first input terminal, and a first output terminal (because the signal of the current regulating circuit 6 is output to the transistors MN1 and MN2, the transistors are considered part of the current regulating unit 6); a second transistor (MN1) comprising a second control terminal, a second input terminal, and a second output terminal (because the signal of the current regulating circuit 6 is output to the transistors MN1 and MN2, the transistors are considered part of the current regulating unit 6); and a second operational amplifier (A3) comprising an inverting input, a non-inverting input, and a second operational amplifier output (where the amplifier has inputs and an output). Lai discloses that the first control terminal is electrically coupled to the second control terminal (the control terminal of MN2 is connected to MN1), the first input terminal is electrically coupled to a power source (MN2 connected to SYS), the power source (SYS) is other than the reference voltage (SYS is different from REF), the first output terminal (of MN2) is electrically and directly coupled to an input end (MP1 through pathway labeled IBFETH) of the current-to-voltage converting unit (5) and the first operational amplifier (A1), the second input terminal (of MN1) is electrically coupled to the power source (MN1 input connected to SYS), the second output terminal (of MN1) is electrically coupled to the first operational amplifier (A1) and the device to be charged (BAT), the non-inverting input (+) of the second operational amplifier (A3) is electrically coupled to the reference voltage (REF), the inverting input (-) of the second operational amplifier (A3) is electrically coupled to a regulating voltage output from the current-to-voltage converting unit (5), and the second operational amplifier (A3) output of the second operational amplifier is electrically and directly coupled to the first control terminal (of MN2) and the control second terminal (of MN1). Lai does not directly disclose that the amplifier A3 within the charging current regulating unit 6 is directly coupled to the first control terminal (MN2) and the second control terminal (MN1). Allgaier discloses a regulating unit comprising an operational amplifier 202 with a current sensing resistor 201 (FIG. 2). The output of the operational amplifier 202 is fed directly to the switching regulator 104 (¶83-84. It would be obvious to one of ordinary skill in the art to replace the charging current regulating unit of Lai with a known charging current regulator that is taught by Allgaier. This type of charging current regulator is used for regulating the charging current without limiting value relating to an input current being exceeded (Allgaier; ¶21), thus preventing overloading of the system. Although Lai discloses the input connections to A3, Lai discloses inverting amplifier connections rather than the non-inverting amplifier connections claimed. Allgaier discloses that the output signal of the operational amplifier either behaves so as to be proportional or inversely proportional (¶86) It would be obvious to one of ordinary skill in the art to provide a non-inverting amplifier to the current regulating unit of Lai in order to provide lower distortion without affecting the frequency response (Bostrom; ¶62). Regarding claim 2, Lai discloses that the charging current (Bat) is M times of the regulating current (page 5,¶5 – current flowing through the second transistor MN2 is 1/N of the current flowing through the first transistor MN1, thus, the current flowing through MN1 is NMN2; page 5, ¶6 – the current flowing through the transistor is determined by the gate voltage which is controlled by the current regulator 6), Although Lai does not expressly state that “N” is an integer, one of ordinary skill in the art would understand that in the context of ratios, N would customarily be an integer. Regarding claim 3, Lai discloses that the first operational amplifier (A1) comprises: An inverting input (negative terminal of A1) electrically coupled to the current regulating unit (6) and the current-to-voltage converting unit (through switch S7). A non-inverting input (+ terminal of A1) electrically coupled to the current regulating unit (6) and the device to be charged (BAT). A first operational amplifier output electrically coupled to the current-to-voltage converting unit (A1 to 5). Regarding claim 5, Lai discloses that the current-to-voltage converting unit (5) comprises: a third transistor (MP1) comprising a third control terminal, a third input terminal, and a third output terminal; and a resistor (R1). Lai discloses that the third control terminal is electrically connected to the first operational amplifier output of the first operational amplifier (A1), the third input terminal (of MP1) is electrically connected to the inverting input (-) of the first operational amplifier (A1), one terminal of the resistor (R1) is electrically connected to the third output terminal (of MP1), and the other terminal of the resistor is electrically connected to the ground (as illustrated at (5) of FIG. 8). Regarding claim 6, Lai discloses that M is a ratio of a channel width/length ratio of the first transistor to a channel width/length ratio of the second transistor (page 2, ¶10; MN1 is the same size as MN2, thus the ratio between transistors is 1:1). Regarding claim 7, the current regulating unit (6) is further configured to adjust the charging voltage of the device to be charged (charging unit 1 is connected to an output of the charging current adjusting unit 6, thus adjusting the charging voltage), and the first operational amplifier (A1) is further configured to regulate the regulating current according to the charging voltage (FIG. 3 - the operation amplifier A1 amplifies compares BFETH and the BAT, thus providing regulation to the charging current regulator 6). Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Lai et al. CN107482722A in view of Wong US20090295339A1 as evidenced by Bostrom US20160352293A1 in further view of Belch US20070052395A1. Regarding claim 10, Lai does not explicitly disclose when the regulating voltage is equal to the reference voltage, the charging current is zero. Belch discloses that when the regulating voltage is equal to the reference voltage, the charging current is zero (¶8 – the current source is decreased to zero when the output voltage is equal to the input voltage). It would be obvious to one of ordinary skill in the art to limit voltage outside of the prescribed limit, as taught by Belch, to Lai, the reduction of the current preventing overcharging and damage to the circuits (Belch; ¶6 and 8). Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Lai et al. CN107482722A in view of Wong US20090295339A1 as evidenced by Bostrom US20160352293A1 and Shimizu et al. US20130328568A1. Regarding claim 11, Lai teaches a constant current charging device (page 2, first paragraph and FIG. 8), configured to charge a device to be charged (BATT). Lai discloses a current regulating unit (A3/1/2) electrically coupled to the device to be charged (BAT) and configured to provide a regulating current (from charging current regulating unit 6) and a charging current (provided to the battery BAT) according to a reference voltage (REF to amplifier A3) wherein the charging current is adjusted according to the regulating current (page 5 - ¶5 - charging current regulating unit compares the sampling voltage with the reference voltage REF to obtain a charging current regulating signal which is fed back to the gate terminal of the first transistor MN1 for controlling and regulating the magnitude of the constant charging current- thus the charging current is adjusted according to the regulating current). Lai discloses that a current-to-voltage converting unit (5) electrically coupled to the current regulating unit (6) and configured to output a regulating voltage (output voltage B – page 6; ¶12) according to the regulating current (from the current regulator 6). Lai discloses a first operational amplifier (A1) electrically coupled to the current regulating unit (6), the current-to-voltage converting unit (5), and the device to be charged (BAT) (adjust the voltage PUMP at the gate of the power transistor so as to control the charging current at a constant value; page 1; ¶3). the current regulating unit (6) comprises: a first transistor (MN2) comprising a first control terminal, a first input terminal, and a first output terminal (because the signal of the current regulating circuit 6 is output to the transistors MN1 and MN2, the transistors are considered part of the current regulating unit 6); a second transistor (MN1) comprising a second control terminal, a second input terminal, and a second output terminal (because the signal of the current regulating circuit 6 is output to the transistors MN1 and MN2, the transistors are considered part of the current regulating unit 6); and a second operational amplifier (A3) comprising an inverting input, a non-inverting input, and a second operational amplifier output (where the amplifier has inputs and an output). Lai discloses that the first control terminal is electrically coupled to the second control terminal (the control terminal of MN2 is connected to MN1), the first input terminal is electrically coupled to a power source (MN2 connected to SYS), the power source (SYS) is other than the reference voltage (SYS is different from REF), the first output terminal (of MN2) is electrically and directly coupled to an input end (MP1 through pathway labeled IBFETH) of the current-to-voltage converting unit (5) and the first operational amplifier (A1), the second input terminal (of MN1) is electrically coupled to the power source (MN1 input connected to SYS), the second output terminal (of MN1) is electrically coupled to the first operational amplifier (A1) and the device to be charged (BAT), the non-inverting input (+) of the second operational amplifier (A3) is electrically coupled to the reference voltage (REF), the inverting input (-) of the second operational amplifier (A3) is electrically and directly coupled to a regulating voltage output from the current-to-voltage converting unit (5), and the second operational amplifier (A3) output of the second operational amplifier is electrically and directly coupled to the first control terminal (of MN2) and the control second terminal (of MN1). Although Lai discloses the input connections to A3, Lai discloses inverting amplifier connections rather than the non-inverting amplifier connections claimed. Further, although Lai discloses a power source and a current regulating unit, Lai does not explicit disclose a voltage detecting unit, wherein the voltage detecting unit is electrically coupled between a power source and the current regulating unit. Lai does not directly disclose that the amplifier A3 within the charging current regulating unit 6 is directly coupled to the first control terminal (MN2) and the second control terminal (MN1). Allgaier discloses a regulating unit comprising an operational amplifier 202 with a current sensing resistor 201 (FIG. 2). The output of the operational amplifier 202 is fed directly to the switching regulator 104 (¶83-84. It would be obvious to one of ordinary skill in the art to replace the charging current regulating unit of Lai with a known charging current regulator that is taught by Allgaier. This type of charging current regulator is used for regulating the charging current without limiting value relating to an input current being exceeded (Allgaier; ¶21), thus preventing overloading of the system. Although Lai discloses the input connections to A3, Lai discloses inverting amplifier connections rather than the non-inverting amplifier connections claimed. Allgaier discloses that the output signal of the operational amplifier either behaves so as to be proportional or inversely proportional (¶86) It would be obvious to one of ordinary skill in the art to provide a non-inverting amplifier to the current regulating unit of Lai in order to provide lower distortion without affecting the frequency response (Bostrom; ¶62). Allgaier does not explicitly teach a voltage detecting unit, wherein the voltage detecting unit is electrically coupled between a power source and the current regulating unit and configured to adjust a charging voltage. Shimizu discloses a voltage detecting unit (10), wherein the voltage detecting unit (10) is electrically coupled between a power source (power arriving via power supply line 55) and the current regulating unit (80) and configured to adjust a charging voltage (¶69 and ¶71). It would be obvious to one of ordinary skill to provide a voltage detecting unit to Lai in order to reduce the dispersion of dark currents (¶15). Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Lai et al. CN107482722A in view of Allgaier et al. US20130106358A1 as evidenced by Bostrom US20160352293A1 and in further view of Huong et al. US20140184160A1. Regarding claim 12. Lai teaches a constant current charging device (page 2, first paragraph and FIG. 8), configured to charge a device to be charged (BATT), and the constant current charging device comprising: Lai discloses a current regulating unit (A3/1/2) electrically coupled to the device to be charged (BAT) and configured to provide a regulating current (from charging current regulating unit 6) and a charging current (provided to the battery BAT) according to a reference voltage (REF to amplifier A3) wherein the charging current is adjusted according to the regulating current (page 5 - ¶5 - charging current regulating unit compares the sampling voltage with the reference voltage REF to obtain a charging current regulating signal which is fed back to the gate terminal of the first transistor MN1 for controlling and regulating the magnitude of the constant charging current- thus the charging current is adjusted according to the regulating current). Lai discloses a current-to-voltage converting unit (5) electrically coupled to the current regulating unit (6). Lai discloses a first operational amplifier (A1) electrically coupled to the current regulating unit (6), the current-to-voltage converting unit (5), and the device to be charged (BAT) (adjust the voltage PUMP at the gate of the power transistor so as to control the charging current at a constant value; page 1; ¶3). the current regulating unit (6) comprises: a first transistor (MN2) comprising a first control terminal, a first input terminal, and a first output terminal (because the signal of the current regulating circuit 6 is output to the transistors MN1 and MN2, the transistors are considered part of the current regulating unit 6); a second transistor (MN1) comprising a second control terminal, a second input terminal, and a second output terminal (because the signal of the current regulating circuit 6 is output to the transistors MN1 and MN2, the transistors are considered part of the current regulating unit 6); and a second operational amplifier (A3) comprising an inverting input, a non-inverting input, and a second operational amplifier output (where the amplifier has inputs and an output). Lai discloses that the first control terminal is electrically coupled to the second control terminal (the control terminal of MN2 is connected to MN1), the first input terminal is electrically coupled to a power source (MN2 connected to SYS), the power source (SYS) is other than the reference voltage (SYS is different from REF), the first output terminal (of MN2) is electrically and directly coupled to an third input end (MP1 through pathway labeled IBFETH) of the current-to-voltage converting unit (5) and the first operational amplifier (A1), the second input terminal (of MN1) is electrically coupled to the power source (MN1 input connected to SYS), the second output terminal (of MN1) is electrically coupled to the first operational amplifier (A1) and the device to be charged (BAT), the non-inverting input (+) of the second operational amplifier (A3) is electrically coupled to the reference voltage (REF), the inverting input (-) of the second operational amplifier (A3) is electrically coupled to a regulating voltage output from the current-to-voltage converting unit (5), and the second operational amplifier (A3) output of the second operational amplifier is electrically and directly coupled to the first control terminal (of MN2) and the control second terminal (of MN1). Lai does not explicitly teach a voltage regulating unit, wherein the voltage regulating unit is electrically coupled between a power source and the current regulating unit. Further, although Lai discloses the input connections to A3, Lai discloses inverting amplifier connections rather than the non-inverting amplifier connections claimed. Lai does not directly disclose that the amplifier A3 within the charging current regulating unit 6 is directly coupled to the first control terminal (MN2) and the second control terminal (MN1). Allgaier discloses a regulating unit comprising an operational amplifier 202 with a current sensing resistor 201 (FIG. 2). The output of the operational amplifier 202 is fed directly to the switching regulator 104 (¶83-84. It would be obvious to one of ordinary skill in the art to replace the charging current regulating unit of Lai with a known charging current regulator that is taught by Allgaier. This type of charging current regulator is used for regulating the charging current without limiting value relating to an input current being exceeded (Allgaier; ¶21), thus preventing overloading of the system. Although Lai discloses the input connections to A3, Lai discloses inverting amplifier connections rather than the non-inverting amplifier connections claimed. Allgaier discloses that the output signal of the operational amplifier either behaves so as to be proportional or inversely proportional (¶86) It would be obvious to one of ordinary skill in the art to provide a non-inverting amplifier to the current regulating unit of Lai in order to provide lower distortion without affecting the frequency response (Bostrom; ¶62). Allgaier does not explicitly teach a voltage regulating unit, wherein the voltage regulating unit is electrically coupled between a power source and the current regulating unit. Huang teaches a voltage regulating unit (24), wherein the voltage regulating unit (24) is electrically coupled between a power source (10) and the current regulating unit (where Lai teaches that the current regulating unit is part of the charger thus, Huang teaches a voltage regulator between the two features). It would be obvious to one of ordinary skill in the art to provide a voltage regulator after the power source in order to supply necessary power needed for charging through buck and boost regulation by a voltage regulator allowing for more efficient charging (Huang; ¶19). Conclusion 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to PAMELA JEPPSON whose telephone number is (571)272-4094. The examiner can normally be reached Monday-Friday 7:30 AM - 5:00 PM.. 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, Drew Dunn can be reached on 571-272-2312. 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. /PAMELA J JEPPSON/Examiner, Art Unit 2859 /DREW A DUNN/Supervisory Patent Examiner, Art Unit 2859
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Prosecution Timeline

Mar 18, 2021
Application Filed
Jan 12, 2024
Non-Final Rejection — §103
Apr 18, 2024
Response Filed
Aug 02, 2024
Non-Final Rejection — §103
Nov 10, 2024
Response Filed
Feb 06, 2025
Final Rejection — §103
May 08, 2025
Request for Continued Examination
May 12, 2025
Response after Non-Final Action
Aug 14, 2025
Non-Final Rejection — §103
Nov 06, 2025
Response Filed
Feb 23, 2026
Final Rejection — §103 (current)

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Expected OA Rounds
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3y 4m
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