Patent ID: 7327203

Claim:
PWM signal generation circuit for generating a PWM signal, comprising: a comparator comprising: a first input terminal, a second input terminal, and an output side of the comparator connected to a power line side through a first resistor; a voltage-dividing circuit for providing a voltage signal to the first input terminal of the comparator, wherein the voltage signal is obtained by dividing a first voltage between the power line and a ground line; an RC serial circuit connected in parallel to the voltage-dividing circuit, the RC serial circuit comprising: a second resistor disposed on the power line side, and a capacitor disposed on the ground line side, wherein the RC serial circuit provides a second voltage to the second input terminal of the comparator, wherein the second voltage depends on an amount of charge in the capacitor; a first feedback line for feeding back an output of the comparator to the first input terminal side; and a second line that connects the output of the comparator to the second input terminal side through a diode and a third resistor, wherein a discharged current from the capacitor flows into the output side of the comparator through the second line, and wherein the diode blocks a current flow from the output side of the comparator toward the second input terminal.