Patent ID: 9671437
Date: 2017-06-06
CPC Classifications: G01R,H02H,H02M,H03K

Claim:
1. An overcurrent detection circuit for use in a driver circuit that turns a switching element ON/OFF to switch input power and that controls operation of the driver circuit by detecting current flowing through the switching element, the switching element having a current detection element incorporated therein, said overcurrent detection circuit comprising: a current detection resistor that generates voltage in proportion to the current flowing through the switching element, based on the output of the current detection element incorporated into the switching element; a reference voltage generation circuit that generates a reference voltage having a temperature characteristic that is in proportion to an output temperature characteristic of the current detection element, by resistance-dividing a predetermined standard voltage; and a comparator that detects overcurrent of the current flowing through the switching element by comparing the reference voltage generated by the reference voltage generation circuit and the voltage detected via the current detection resistor, wherein the reference voltage generation circuit includes a first resistance voltage dividing circuit comprising a first resistor and a second resistor connected in series between the standard voltage and an output voltage output from the switching element, wherein the first resistor has a resistance temperature coefficient such that a resistance of the first resistor rises and falls proportionally to a rise and fall of a temperature of the first resistor, and wherein the second resistor has a resistance temperature coefficient such that a resistance of the second resistor is independent of a temperature of the second resistor.