Patent attributes
A switching power supply equipment has a function to protect a power supply from abnormalities such as an output short-circuit. An output signal from an error amplification circuit to amplify a difference voltage between an output voltage and a predetermined voltage is input into a feedback terminal of an integrated circuit power supply control circuit, and a power transistor is controlled by a pulse-width control circuit base on the output signal. n addition, a comparator having a reference voltage and a series circuit of a capacitor and a resistor making operation of an overload protection circuit delay are connected to a connecting point of the error amplification circuit and the pulse-width control circuit. The overload protection circuit starts operation by an output of the comparator. The number of required terminals of the integrated circuit is decreased and also a package size of the integrated circuit is decreased in comparison to convention switching power supply equipment incorporating similar protection circuitry.
