# US 9,001,537 B2 · Power factor correction circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,001,537 B2 - Document ID: US9001537B2 - Status: Granted - Kind: B2 - Application number: 13/523,615 - Filed: 2012-06-14 - Published: 2013-10-03 - Granted: 2015-04-07 - Earliest claimed: 2012-03-29 - Assignees: Delta Electronics, Inc. - Applicants: Hong-Yuan Jin; Yan Chen; Hong-Jian Gan; Jian-Ping Ying - Inventors: Hong-Yuan Jin; Yan Chen; Hong-Jian Gan; Jian-Ping Ying - Web page: https://patentgrep.com/patent/US9001537B2 ## CPC - H02M 1/4233: {using a bridge converter comprising active switches} - H02M 1/0048: {Circuits or arrangements for reducing losses (using snubbers H02M1/34)} - H02M 1/0085: {Partially controlled bridges} - H02M 7/2195: {the switches being synchronously commutated at the same frequency of the AC input voltage} - Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes - 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) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A power factor correction (PFC) circuit includes an AC power, a first bridge arm and a second bridge arm. The first bridge arm includes first and second switches connected in series with each other. A second terminal of the first switch is connected to a first terminal of the second switch, and coupled to a first end of the AC power via a first inductor. The second bridge arm includes third and fourth switches connected in series with each other. A second terminal of the third switch is connected to a first terminal of the fourth switch and a second end of the AC power. The third and fourth switches operate in ON/OFF states by use of a control signal having an operation frequency consistent with that of the AC power. The on-state resistance of the third and fourth switches is lower than that of the first or second switch. ## Claims ### Claim 1 A power factor correction (PFC) circuit, comprising: an AC power having a first end and a second end; a first bridge arm comprising a first switch and a second switch connected in series with each other and each having a first terminal and a second terminal, wherein the second terminal of the first switch is connected to the first terminal of the second switch, and is coupled to the first end of the AC power via a first inductor; and a second bridge arm connected in parallel with the first bridge arm, wherein the second bridge arm comprises a third switch and a fourth switch connected in series with each other and each having a first terminal and a second terminal, and the second terminal of the third switch is connected to the first terminal of the fourth switch and the second end of the AC power; wherein the third switch and the fourth switch operate in ON/OFF states by use of a control signal having an operation frequency consistent with that of the AC power, and the on-state resistance of the third switch and the fourth switch is lower than the on-state resistance of the first switch or the second switch. ### Claim 2 (depends on 1) The PFC circuit of claim 1, further comprising a third bridge arm connected in parallel with the first bridge arm and the second bridge arm, wherein the third bridge arm comprises a fifth switch and a sixth switch connected in series with each other and each having a first terminal and a second terminal, and the second terminal of the fifth switch is connected with the first terminal of the sixth switch, and is coupled to the first end of the AC power via a second inductor. ### Claim 3 (depends on 2) The PFC circuit of claim 2, wherein the first switch of the first bridge arm and the fifth switch of the third bridge arm operate in an alternating manner. ### Claim 4 (depends on 1) The PFC circuit of claim 1, wherein the on-state resistance of the third switch and the fourth switch is half of the on-state resistance of the first switch or the second switch. ### Claim 5 (depends on 1) The PFC circuit of claim 1, further comprising a first surge diode and a second surge diode connected in series with each other and each having a cathode and an anode, wherein the cathode of the first surge diode is connected to the first terminal of the third switch, the anode of the second surge diode is connected to the second terminal of the fourth switch, and the anode of the first surge diode is connected with the cathode of the second surge diode and the second end of the AC power. ### Claim 6 (depends on 5) The PFC circuit of claim 5, wherein each of the first surge diode and the second surge diode is a slow-recovery diode. ### Claim 7 (depends on 6) The PFC circuit of claim 6, wherein when the current flowing through the third switch is less than a predetermined threshold, the first surge diode is in a turned-off state. ### Claim 8 (depends on 7) The PFC circuit of claim 7, wherein when the current flowing through the third switch is larger than the predetermined threshold, the first surge diode is in a turned-on state, and the currents respectively flowing through the third switch and the first surge diode are distributed according to a corresponding on-state resistance. ### Claim 9 (depends on 1) The PFC circuit of claim 1, further comprising a third surge diode and a fourth surge diode connected in series with each other and each having a cathode and an anode, wherein the cathode of the third surge diode is connected to the first terminal of the first switch, the anode of the fourth surge diode is connected to the second terminal of the second switch, and the anode of the third surge diode is connected with the cathode of the fourth surge diode and the first end of the AC power. ### Claim 10 (depends on 1) The PFC circuit of claim 1, further comprising a first surge diode and a second surge diode connected in series with each other and each having a cathode and an anode, and a third surge diode and a fourth surge diode connected in series with each other and each having a cathode and an anode, wherein the anode of the first surge diode is connected with the cathode of the second surge diode and the second end of the AC power, and the anode of the third surge diode is connected with the cathode of the fourth surge diode and the first end of the AC power. ### Claim 11 (depends on 10) The PFC circuit of claim 10, further comprising a clamp capacitor, wherein one terminal of the clamp capacitor is connected to the first terminal of the third switch of the second bridge arm, and the other terminal of the clamp capacitor is connected to the second terminal of the fourth switch of the second bridge arm. ### Claim 12 (depends on 11) The PFC circuit of claim 11, wherein when the voltage between the first end and the second end of the AC power is positive, the surge current sequentially flows through the third surge diode, the clamp capacitor and the second surge diode, so as to form a release circuit. ### Claim 13 (depends on 11) The PFC circuit of claim 11, wherein when the voltage between the first end and the second end of the AC power is negative, the surge current sequentially flows through the first surge diode, the clamp capacitor and the fourth surge diode, so as to form a release circuit. ### Claim 14 (depends on 1) The PFC circuit of claim 1, wherein each of the first switch and the second switch is a wide band gap (WBG) semiconductor component. ### Claim 15 (depends on 14) The PFC circuit of claim 14, wherein the WBG semiconductor component is silicon carbide or gallium nitride.