摘要 |
A power supply device is provided with an output transistor for outputting a switch voltage having a rectangular waveform, based on an input signal by being switching-controlled by a pulse width modulation signal; a reference voltage generating circuit for generating a prescribed reference voltage; an error amplifier wherein a feedback voltage depending on the switch voltage and the reference voltage are inputted, an error voltage is generated by amplifying a difference between the voltages, and changes a gain of itself, in accordance with a current signal generated inside based on the feedback voltage and the reference voltage; an oscillator for generating an oscillation signal; and a comparator wherein the oscillation signal and the error voltages are inputted and the pulse width modulation signal is outputted by comparing the voltages. |