Switch controller, switch control method, and power supply device comprising the switch controller
AssigneeFairchild Korea Semiconductor Ltd.
InventorsMin-Woo LEE, Kyung-Oun JANG
Life of this patent
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Abstract
The present invention relates to a switch controller, a switch control method, and a power supply using the switch controller. A switch controller controls switching operation of a power switch and receives a sense voltage of a sense resistor to which a drain current flowing in the power switch flows. The switch controller generates a sum signal using the sense voltage and a ramp signal having a cycle that is the same as a switching cycle of the power switch. The switch controller determines short-circuit of the sense resistor by detecting slope variation of the sum signal.
Claims21
A switch controller controlling for switching operation of a power switch and receiving a sense voltage, of a sense resistor, based on a drain current flowing in the power switch, the switch controller comprising:
- signal generator circuitry configured to generate a sum signal based on the sense voltage and a ramp signal, wherein the ramp signal has a cycle that is approximately the same as a switching cycle of the power switch;
- and
- slope detection circuitry configured to determine a short circuit condition of the sense resistor by determining a slope variation of the sum signal.
A switch control method comprising:
- receiving a sense voltage of a sense resistor configured to receive a drain current of a power switch;
- generating a sum signal based on the sense voltage and a ramp signal having a cycle that is the same as a switching cycle of the power switch;
- and
- determining a short circuit condition of the sense resistor by determining slope variation of the sum signal.
A power supply comprising:
- a power switch;
- inductor circuitry coupled between the power switch and an input voltage;
- sense resistor circuitry coupled between the power switch and a reference potential;
- and
- switch controller circuitry configured to generate a sum signal based on a sense voltage generated by the sense resistor circuitry and a ramp signal generated based on a clock signal that determines a switching frequency of the power switch, the switch controller circuitry is further configured to determine whether the sense resistor is in a short circuit condition by determining slope variation of the sum signal.
Dependencies are inferred from the claim text.