# US 2021/0281166 A1 · Power factor correction controller and operational method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0281166 A1 - Document ID: US20210281166A1 - Status: Published application - Kind: A1 - Application number: 16/953,293 - Filed: 2020-11-19 - Published: 2021-09-09 - Earliest claimed: 2020-03-09 - Assignees: Leadtrend Technology Corp. - Applicants: Leadtrend Technology Corp. - Inventors: Ming-Chang Tsou; Kuan-Hsien Chou; Yi-Chuan Tsai; Cheng-Tsung Ho - Web page: https://patentgrep.com/patent/US20210281166A1 ## CPC - H02M 1/4258: {using a single converter stage both for correction of AC input power factor and generation of a regulated and galvanically isolated DC output voltage (H02M1/4241 takes precedence)} - H02M 1/0019: {the disturbance parameters being load current fluctuations} - H02M 1/0022: {the disturbance parameters being input voltage fluctuations} - H02M 1/0032: {Control circuits allowing low power mode operation, e.g. in standby mode} - H02M 1/007: {Plural converter units in cascade (push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826)} - H02M 3/33523: {with galvanic isolation between input and output of both the power stage and the feedback loop} - H02M 1/0009: {Devices or circuits for detecting current in a converter} - H02M 1/348: {Passive dissipative snubbers} - H02M 1/4208: {Arrangements for improving power factor of AC input} - H02M 1/4225: {using a non-isolated boost converter} - H02M 1/4241: {using a resonant converter} - H02M 1/4266: {using passive elements} - H02M 7/06: using discharge tubes without control electrode or semiconductor devices without control electrode - 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 A power factor correction (PFC) controller applied to a primary side of a power converter includes a feedback pin, a sensing pin, a current detecting circuit, an output voltage detecting circuit, and a determination circuit. The current detecting circuit is coupled to the feedback pin and the sensing pin for detecting an output current of a secondary side of the power converter according to a feedback voltage of the feedback pin and a sensing voltage of the sensing pin. The output voltage detecting circuit is coupled to the feedback pin for detecting an output voltage of the secondary side of the power converter according to the feedback voltage. The determination circuit is coupled to the current detecting circuit and the output voltage detecting circuit for turning on or turning off a PFC circuit coupled to the power converter according to the output current and the output voltage. ## Claims ### Claim 1 A power factor correction controller applied to a primary side of a power converter, comprising: a feedback pin; a sensing pin; a current detecting circuit coupled to the feedback pin and the sensing pin for detecting an output current of a secondary side of the power converter according to a feedback voltage of the feedback pin and a sensing voltage of the sensing pin; an output voltage detecting circuit coupled to the feedback pin for detecting an output voltage of the secondary side of the power converter according to the feedback voltage; and a determination circuit coupled to the current detecting circuit and the output voltage detecting circuit for turning on or turning off a power factor correction circuit coupled to the power converter according to the output current and the output voltage. ### Claim 2 (depends on 1) The power factor correction controller of claim 1, wherein the power converter is a flyback power converter. ### Claim 3 (depends on 1) The power factor correction controller of claim 1, wherein the determination circuit linearly or stepwise turns on or turns off the power factor correction circuit according to the output current and the output voltage. ### Claim 4 (depends on 1) The power factor correction controller of claim 1, further comprising: an input voltage detecting circuit coupled to an input voltage pin further comprised in the power factor correction controller, wherein the input voltage detecting circuit is used for detecting an input voltage inputted to the primary side of the power converter, and the input voltage is an alternating voltage. ### Claim 5 (depends on 4) The power factor correction controller of claim 4, wherein the determination circuit turns on or turns off the power factor correction circuit further according to the output current, the output voltage, and the input voltage. ### Claim 6 (depends on 4) The power factor correction controller of claim 4, wherein the determination circuit utilizes an inner multiplier to multiply the output current by the output voltage to determine output power of the power converter, and turns on or turns off the power factor correction circuit according to the output power and the input voltage. ### Claim 7 (depends on 4) The power factor correction controller of claim 4, wherein after the output voltage is greater than a predetermined voltage, the determination circuit starts to turn on or turn off the power factor correction circuit according to the output voltage, the output current, and the input voltage. ### Claim 8 (depends on 1) The power factor correction controller of claim 1, wherein the determination circuit utilizes an inner multiplier to multiply the output current by the output voltage to determine output power of the power converter, and turns on or turns off the power factor correction circuit according to the output power. ### Claim 9 (depends on 1) The power factor correction controller of claim 1, wherein after the output voltage is greater than a predetermined voltage, the determination circuit starts to turn on or turn off the power factor correction circuit according to the output voltage and the output current. ### Claim 10 An operational method of a power factor correction controller applied to a primary side of a power converter, wherein the power factor correction controller comprises a feedback pin, a sensing pin, a current detecting circuit, an output voltage detecting circuit, and a determination circuit, the operational method comprising: the current detecting circuit detecting an output current of a secondary side of the power converter according to a feedback voltage of the feedback pin and a sensing voltage of the sensing pin; the output voltage detecting circuit detecting an output voltage of the secondary side of the power converter according to the feedback voltage; and the determination circuit turning on or turning off a power factor correction circuit coupled to the power converter according to the output current and the output voltage. ### Claim 11 (depends on 10) The operational method of claim 10, wherein the determination circuit turns on or turns off the power factor correction circuit linearly or stepwise according to the output current and the output voltage. ### Claim 12 (depends on 10) The operational method of claim 10, further comprising: an input voltage detecting circuit detecting an input voltage inputted to the primary side of the power converter, wherein the input voltage is an alternating voltage; and the determination circuit further turning on or turning off the power factor correction circuit according to the output current, the output voltage, and the input voltage. ### Claim 13 (depends on 12) The operational method of claim 12, wherein the determination circuit utilizes an inner multiplier to multiply the output current by the output voltage to determine output power of the power converter, and turns on or turns off the power factor correction circuit according to the output power and the input voltage. ### Claim 14 (depends on 12) The operational method of claim 12, wherein after the output voltage is greater than a predetermined voltage, the determination circuit starts to turn on or turn off the power factor correction circuit according to the output voltage, the output current, and the input voltage. ### Claim 15 (depends on 10) The operational method of claim 10, wherein the determination circuit utilizes an inner multiplier to multiply the output current by the output voltage to determine output power of the power converter, and turns on or turns off the power factor correction circuit according to the output power. ### Claim 16 (depends on 10) The operational method of claim 10, wherein after the output voltage is greater than a predetermined voltage, the determination circuit starts to turn on or turn off the power factor correction circuit according to the output voltage and the output current.