Patent ID: 7010007

Claim:
A light-emitting diode lighting circuit for activating a semiconductor switching device to illuminate at least one light-emitting diode, the light-emitting diode lighting circuit comprising: a differential amplifier provided at a preceding stage of the semiconductor switching device; a switch for inputting a supply voltage to a positive input side of the differential amplifier; a reference resistor having one end connected to the positive input side of the differential amplifier, and the other end grounded; and at least one voltage-dividing resistor connected to a negative input side of the differential amplifier for dividing the supply voltage, wherein a resistance value Rref of the reference resistor and a resistance value R 1 /R 2 of the voltage-dividing resistors are decided such that a relationship between a leakage resistance value Rs of the switch and both resistance values Rref and R 1 /R 2 becomes Rs>(R 1 /R 2 )×Rref.