# US 10,771,050 B2 · Gate driving circuit and switching power supply apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,771,050 B2 - Document ID: US10771050B2 - Status: Granted - Kind: B2 - Application number: 16/392,622 - Filed: 2019-04-24 - Published: 2019-11-14 - Granted: 2020-09-08 - Earliest claimed: 2018-05-09 - Assignees: Fuji Electric Co., Ltd. - Applicants: Fuji Electric Co., Ltd. - Inventors: Hirotoshi Kaneda - Web page: https://patentgrep.com/patent/US10771050B2 ## CPC - H03K 17/08128: {in composite switches} - H03K 17/163: {Soft switching} - H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 7/5387: in a bridge configuration - H03K 17/168: {in composite switches} - H02M 1/0054: {Transistor switching losses (periodically suspending operation of switching converter in low power mode H02M1/0035)} - H03K 2217/0027: Measuring means of, e.g. currents through or voltages across the switch - H03K 2217/0036: Means reducing energy consumption - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - 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 gate driving circuit that drives a gate of a main switching device is provided, where the gate driving circuit includes: a first resistor connected between a first potential and the gate of the main switching device; a second resistor connected between a second potential being lower than the first potential and the gate of the main switching device; a first switching device connected in series with the first resistor between the first potential and the gate of the main switching device; a second switching device connected in series with the second resistor between the second potential and the gate of the main switching device; and a control circuit that changes at least one resistance value of a resistance value of the first resistor and a resistance value of the second resistor according to a length of an ON period during which the main switching device is turned on. ## Claims ### Claim 1 A gate driving circuit that drives a gate of a main switching device, the gate driving circuit comprising: a first resistor that is connected between a first potential and the gate of the main switching device; a second resistor that is connected between a second potential lower than the first potential and the gate of the main switching device; a first switching device that is connected in series with the first resistor between the first potential and the gate of the main switching device; a second switching device that is connected in series with the second resistor between the second potential and the gate of the main switching device; and a control circuit that changes at least one resistance value of a resistance value of the first resistor and a resistance value of the second resistor according to a length of an ON period during which the main switching device is turned on. ### Claim 2 (depends on 1) The gate driving circuit according to claim 1, wherein the control circuit sets the resistance value of the second resistor to be larger when the ON period is a first period than when the ON period is a second period that is shorter than the first period. ### Claim 3 (depends on 2) The gate driving circuit according to claim 2, wherein at least one of the first resistor and the second resistor is a voltage-controlled resistor having a resistance value that is continuously changeable according to an input voltage, and as the ON period is longer within a predetermined range, the control circuit supplies a voltage that causes the resistance value to be large to the voltage-controlled resistor. ### Claim 4 (depends on 3) The gate driving circuit according to claim 3, wherein the voltage-controlled resistor has a field effect transistor that changes a resistance value between two main terminals according to a voltage input to a control terminal. ### Claim 5 (depends on 1) The gate driving circuit according to claim 1, wherein the control circuit sets the resistance value of the first resistor to be smaller when the ON period is a third period than when the ON period is a fourth period that is shorter than the third period. ### Claim 6 (depends on 1) The gate driving circuit according to claim 1, wherein the control circuit controls the first switching device and the second switching device according to an input control signal, and determines the length of the ON period according to a length of a specified period during which the main switching device is turned on by the control signal. ### Claim 7 (depends on 6) The gate driving circuit according to claim 6, wherein the control circuit sets the at least one resistance value during a current ON period according to a length of a previous or former ON period. ### Claim 8 (depends on 6) The gate driving circuit according to claim 6, wherein the control signal specifies the ON period by a pulse, and the control circuit sets the at least one resistance value according to a width of the pulse. ### Claim 9 (depends on 1) A switching power supply apparatus comprising the driving circuit according to claim 1; the main switching device; and a freewheeling diode connected with the main switching device in anti-parallel. ### Claim 10 A gate driving circuit that drives a gate of a main switching device, the gate driving circuit comprising: a first resistor that is connected between a first potential and the gate of the main switching device; a second resistor that is connected between a second potential being lower than the first potential and the gate of the main switching device; a first switching device that is connected in series with the first resistor between the first potential and the gate of the main switching device; a second switching device that is connected in series with the second resistor between the second potential and the gate of the main switching device; a detecting section that detects a magnitude of measurement target current including current that flows through the main switching device during a period during which the main switching device is turned on; and a control circuit that changes at least one resistance value of a resistance value of the first resistor and a resistance value of the second resistor according to the detected magnitude of the measurement target current, wherein the control circuit sets the resistance value of the second resistor to be larger when the detected magnitude of the measurement target current is a first magnitude than when the detected magnitude of the measurement target current is a second magnitude that is smaller than the first magnitude, and the control circuit sets the resistance value of the second resistor during a current ON period according to the magnitude of the measurement target current measured during a previous ON period. ### Claim 11 (depends on 10) The gate driving circuit according to claim 10, wherein the control circuit sets the resistance value of the first resistor to be smaller when the detected magnitude of the measurement target current is a third magnitude than when the detected magnitude of the measurement target current is a fourth magnitude that is smaller than the third magnitude. ### Claim 12 (depends on 10) The gate driving circuit according to claim 10, wherein the detecting section samples a magnitude of the measurement target current at a predetermined timing during the period during which the main switching device is turned on. ### Claim 13 (depends on 10) A switching power supply apparatus comprising the driving circuit according to claim 10; the main switching device; and a freewheeling diode connected with the main switching device in anti-parallel. ### Claim 14 A gate driving circuit that drives a gate of a main switching device, the gate driving circuit comprising: a first resistor that is connected between a first potential and the gate of the main switching device; a second resistor that is connected between a second potential being lower than the first potential and the gate of the main switching device; a first switching device that is connected in series with the first resistor between the first potential and the gate of the main switching device; a second switching device that is connected in series with the second resistor between the second potential and the gate of the main switching device; a detecting section that detects a magnitude of opposite measurement target current including current that flows from a negative-side main terminal side toward a positive-side main terminal side of an opposite switching device connected in series with the main switching device during a period during which the main switching device is turned off; and a control circuit that changes a resistance value of the first resistor according to the magnitude of the opposite measurement target current. ### Claim 15 (depends on 14) The gate driving circuit according to claim 14, wherein the detecting section further detects a magnitude of measurement target current including current that flows through the main switching device during a period during which the main switching device is turned on, and the control circuit further changes a resistance value of the second resistor according to the detected magnitude of the measurement target current. ### Claim 16 (depends on 14) The gate driving circuit according to claim 14, wherein the control circuit sets the resistance value of the first resistor to be smaller when the detected magnitude of the opposite measurement target current is a third magnitude than when the detected magnitude of the opposite measurement target current is a fourth magnitude that is smaller than the third magnitude. ### Claim 17 (depends on 14) The gate driving circuit according to claim 14, wherein the detecting section samples the magnitude of the opposite measurement target current at a predetermined timing during a period during which the opposite switching device is turned on. ### Claim 18 (depends on 14) A switching power supply apparatus comprising the gate driving circuit according to claim 14; the main switching device; and a freewheeling diode connected with the main switching device in anti-parallel. ### Claim 19 A gate driving circuit that drives a gate of a main switching device, the gate driving circuit comprising: a first resistor that is connected between a first potential and the gate of the main switching device; a second resistor that is connected between a second potential being lower than the first potential and the gate of the main switching device; a first switching device that is connected in series with the first resistor between the first potential and the gate of the main switching device; a second switching device that is connected in series with the second resistor between the second potential and the gate of the main switching device; a detecting section that detects a magnitude of measurement target current including current that flows through the main switching device during a period during which the main switching device is turned on; and a control circuit that changes at least one resistance value of a resistance value of the first resistor and a resistance value of the second resistor according to the detected magnitude of the measurement target current, wherein the detecting section samples a magnitude of the measurement target current at a predetermined timing during the period during which the main switching device is turned on, the predetermined timing being set after a lapse of a certain time period from a falling of a control signal to the main switching device.