# US 2014/0152239 A1 · Self-adaptive input power charger and method for controlling input current of charger > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152239 A1 - Document ID: US20140152239A1 - Status: Published application - Kind: A1 - Application number: 14/073,052 - Filed: 2013-11-06 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Silergy Semiconductor Technology (Hangzhou) LTD - Applicants: Silergy Semiconductor Technology (Hangzhou) LTD - Inventors: Jie Yao; Wei Chen; Chen Zhao; Shuai Cheng - Web page: https://patentgrep.com/patent/US20140152239A1 ## CPC - H02J 7/963: {in response to battery voltage gradient} - H02J 7/927: {with introduction of pulses during the charging process} - H02J 7/953: {in response to charge current gradient} - H02M 1/0009: {Devices or circuits for detecting current in a converter} - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract Disclosed herein are circuits and methods for limiting a charger input current. In one embodiment, a self-adaptive input power charger for charging a battery, can include: (i) a power stage circuit configured to receive an external input power supply that supplies an input voltage and an input current to the charger; (ii) a comparison circuit configured to generate a comparison result indicating that the input power supply has entered a current-limiting state when the input voltage is less than a first reference voltage; (iii) a current regulation circuit configured to generate a first control signal in response to the comparison result; and (iv) a driving control circuit configured to limit the input current by the first control signal. ## Claims ### Claim 1 A self-adaptive input power charger for charging a battery, the charger comprising: a) a power stage circuit configured to receive an external input power supply that supplies an input voltage and an input current to said charger; b) a comparison circuit configured to generate a comparison result indicating that said input power supply has entered a current-limiting state when said input voltage is less than a first reference voltage; c) a current regulation circuit configured to generate a first control signal in response to said comparison result; and d) a driving control circuit configured to limit said input current by said first control signal. ### Claim 2 (depends on 1) The charger of claim 1, wherein said comparison circuit comprises a first error amplifier configured to receive said input voltage and said first reference voltage, and to generate said comparison result. ### Claim 3 (depends on 2) The charger of claim 2, wherein said current regulation circuit comprises a first diode having a cathode coupled to said comparison result, and an anode coupled to said first control signal and said driving control circuit, and wherein said driving control circuit is configured to control a duty cycle of a power switch in said power stage circuit based on said first control signal to limit said input current of said charger. ### Claim 4 (depends on 3) The charger of claim 3, wherein said driving control circuit comprises a pulse-width modulation (PWM) controller configured to receive said first control signal, and wherein said duty cycle of said power switch is controlled by said PWM controller. ### Claim 5 (depends on 3) The charger of claim 3, wherein said driving control circuit comprises a current control loop configured to receive said first control signal, and wherein said duty cycle of said power switch is controlled by regulating a voltage reference for said current control loop. ### Claim 6 (depends on 5) The charger of claim 5, wherein said comparison circuit comprises a first comparator configured to receive said input voltage and said first reference voltage, and to generate a first comparison signal as said comparison result. ### Claim 7 (depends on 6) The charger of claim 6, wherein said current regulation circuit is configured to generate said first control signal based on said first comparison signal, and wherein: a) when said input voltage is less than said first reference voltage, said first control signal is configured to decrease said voltage reference for said current control loop to limit said input current of said charger; and b) when said input voltage is greater than said first reference voltage, said first control signal is configured to increase said voltage reference for said current control loop to increase said input current of said charger. ### Claim 8 (depends on 7) The charger of claim 7, wherein said current regulation circuit comprises: a) a charging control circuit configured to receive said first comparison signal and a charging power supply, and to control said charging power supply to charge an energy storage component based on said first comparison signal; and b) a discharging control circuit configured to discharge said energy storage component based on said first comparison signal, wherein a voltage across said energy storage component is configured as said first control signal. ### Claim 9 (depends on 8) The charger of claim 8, wherein said discharging control circuit is configured to compare said input voltage against a second reference voltage, and to generate a second comparison signal to control a discharging speed of said energy storage component. ### Claim 10 (depends on 7) The charger of claim 7, wherein said current regulation circuit comprises: a) a plus-minus counter configured to receive said first comparison signal and a second clock signal, and to generate a digital control signal; and b) a digital-analog converter configured to convert said digital control signal to an analog control signal configured to be transmitted to said current control loop as said first control signal. ### Claim 11 A method, comprising: a) receiving, by a power stage circuit, an external input power supply that supplies an input voltage and an input current to a charger for charging a battery; b) generating, by a comparison circuit, a comparison result indicating that said input power supply has entered a current-limiting state when said input voltage is less than a first reference voltage; c) generating, by a current regulation circuit, a first control signal in response to said comparison result; and d) limiting, by a driving control circuit, said input current using said first control signal. ### Claim 12 (depends on 11) The method of claim 11, wherein said generating said comparison result comprises amplifying an error signal resulting from comparing said input voltage against said first reference voltage. ### Claim 13 (depends on 12) The method of claim 12, further comprising: a) generating said first control signal from said error signal; and b) and limiting said input current by controlling a duty cycle of a power switch in said power stage circuit based on said first control signal. ### Claim 14 (depends on 13) The method of claim 13, wherein said controlling said duty cycle of said power switch comprises using a pulse-width modulation (PWM) controller. ### Claim 15 (depends on 13) The method of claim 13, wherein said controlling said duty cycle of said power switch comprises regulating a voltage reference for a current control loop. ### Claim 16 (depends on 15) The method of claim 15, wherein said generating said comparison result comprises comparing said input voltage against said first reference voltage, to output a first comparison signal. ### Claim 17 (depends on 16) The method of claim 16, further comprising: a) generating said first control signal based on said first comparison signal; b) decreasing said voltage reference for said current control loop to limit said input current of said charger when said input voltage is less than said first reference voltage; and c) increasing said voltage reference for said current control loop to increase said input current of said charger when said input voltage is greater than said first reference voltage.