# US 12,003,180 B2 · Power supply for driving synchronous rectification elements of SEPIC converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,180 B2 - Document ID: US12003180B2 - Status: Granted - Kind: B2 - Application number: 17/486,974 - Filed: 2021-09-28 - Published: 2022-06-23 - Granted: 2024-06-04 - Earliest claimed: 2020-12-21 - Assignees: Sanken Electric Co., Ltd. - Applicants: Sanken Electric Co., Ltd. - Inventors: Masaru Nakamura; Shinji Aso; Jianao Yao - Web page: https://patentgrep.com/patent/US12003180B2 ## CPC - H02M 3/1588: {comprising at least one synchronous rectifier element (H02M3/1582, H02M3/1584 take precedence)} - H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters - H02M 3/1557: {Single ended primary inductor converters [SEPIC]} - H02M 1/0006: {Arrangements for supplying an adequate voltage to the control circuit of converters} - 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 DC-DC converter according to one or more embodiments is disclosed that may include: a drive voltage switching circuit of a drive circuit that drives a synchronous rectification MOS transistor. The drive voltage switching circuit may switch a connection so that the drive circuit supplies power from the output voltage to the drive circuit in response to the drive voltage for supplying power to the drive circuit being set to be lower than the output voltage. The drive voltage switching circuit may switch a connection so that the drive circuit supplies power from the drive voltage in response to the drive voltage for supplying power to the drive circuit being set to be higher than the output voltage. ## Claims ### Claim 1 A DC-DC converter comprising: a first inductor connected between an input power supply and a first terminal of a coupling capacitor; a first switching element connected between the first terminal of the coupling capacitor and a ground; a second inductor connected between a second terminal of the coupling capacitor and the ground; a second switching element connected between the second terminal of the coupling capacitor and an output terminal; a drive circuit that drives the second switching element; a drive voltage supply circuit that supplies power to the drive circuit; a drive voltage switching circuit that switches a drive voltage of the drive circuit, wherein the drive voltage switching circuit switches a connection so that the drive circuit supplies power with an output voltage or a voltage higher than the output voltage in response to the output voltage being higher than the drive voltage, and the drive voltage switching circuit switches a connection so as to supply power to the drive circuit from the drive voltage in response to the output voltage being lower than the drive voltage; an AD converter that detects the output voltage, and converts the output voltage into a digital value; a subtractor that outputs a difference between the digital value and an output target value; a filter calculation circuit that calculates an operation value based on the difference; and a PWM signal generation circuit that generates a PWM signal corresponding to the operation value, wherein the drive circuit outputs a voltage from the drive voltage switching circuit to the second switching element to drive the second switching element based on the PWM signal. ### Claim 2 (depends on 1) The DC-DC converter according to claim 1, wherein the drive voltage switching circuit comprises: a first rectification circuit connected between the drive voltage and the drive circuit; and a second rectification circuit connected between the output voltage and the drive circuit. ### Claim 3 (depends on 1) The DC-DC converter according to claim 1, wherein the drive voltage switching circuit comprises: a first rectification circuit connected between the drive voltage and the drive circuit; and a second rectification circuit connected between the output voltage and the drive circuit, wherein the second rectification circuit is connected to a connecting point of the second terminal of the coupling capacitor and the second switching element. ### Claim 4 A DC-DC converter comprising: a first inductor connected between an input power supply and a first terminal of a coupling capacitor; a first switching element connected between the first terminal of the coupling capacitor and a ground; a second inductor connected between a second terminal of the coupling capacitor and the ground; a second switching element connected between the second terminal of the coupling capacitor and an output terminal; a drive circuit that drives the second switching element; a drive voltage supply circuit that supplies power to the drive circuit; and a drive voltage switching circuit that switches the drive voltage of the drive circuit, wherein the drive voltage switching circuit switches a connection so that the drive circuit supplies power with an output voltage or a voltage higher than the output voltage in response to the output voltage being higher than the drive voltage, and the drive voltage switching circuit switches a connection so as to supply power to a drive circuit from the drive voltage in response to the output voltage being lower than the drive voltage, wherein the DC-DC converter further comprises: a third inductor, wherein the third inductor is connected between a connecting point of the second terminal of the coupling capacitor and the second inductor and the second switching element; and a second rectification circuit, wherein the second rectification circuit is connected to the connecting point of the second terminal of the coupling capacitor and the second inductor. ### Claim 5 A DC-DC converter comprising: a first inductor connected between an input power supply and a first terminal of a coupling capacitor; a first switching element connected between the first terminal of the coupling capacitor and a ground; a second inductor connected between a second terminal of the coupling capacitor and the ground; a second switching element connected between the second terminal of the coupling capacitor and an output terminal; a drive circuit that drives the second switching element; a drive voltage supply circuit that supplies power to the drive circuit; and a drive voltage switching circuit that switches the drive voltage of the drive circuit, wherein the drive voltage switching circuit switches a connection so that the drive circuit supplies power with an output voltage or a voltage higher than the output voltage in response to the output voltage being higher than the drive voltage, and the drive voltage switching circuit switches a connection so as to supply power to a drive circuit from the drive voltage in response to the output voltage being lower than the drive voltage, wherein the DC-DC converter further comprises: a third inductor, wherein one end of the third inductor is connected to the second terminal of the coupling capacitor, and the other end is connected to a connecting point of the second inductor and the second switching element, and a second rectification circuit, wherein the second rectification circuit is connected to a connecting point of the second terminal of the coupling capacitor and the third inductor. ### Claim 6 (depends on 1) The DC-DC converter according to claim 1, wherein the drive voltage switching circuit comprises: a first rectification circuit connected between the drive voltage and the drive circuit; and a second rectification circuit connected between a connecting point of the first terminal of the coupling capacitor and the first switching element and the drive circuit. ### Claim 7 (depends on 1) The DC-DC converter according to claim 1, wherein the DC-DC converter comprises a synchronous rectification having a single ended primary inductor converter (SEPIC) type DC-DC converter.