Switching regulator and electronic device

摘要

There is provided a switching regulator including an overcurrent protection circuit which is able to automatically return from an overcurrent state. The switching regulator includes an error amplification circuit which amplifies a difference between a feedback voltage and a reference voltage based on an output voltage and outputs the amplified difference; a PWM comparator which compares an output of the error amplification circuit with an output of a triangular wave oscillation circuit, and controls an output transistor; an overcurrent detection circuit which monitors a load current flowing through a load connected to an output terminal, detects that the load current is an overcurrent, and outputs an overcurrent detection signal causing a switching operation to stop; and a negative feedback control circuit which receives the overcurrent detection signal, and controls the load current to a predetermined current value.

主权项

1. A switching regulator comprising:
an error amplification circuit which amplifies a difference between a feedback voltage and a reference voltage based on an output voltage and outputs the amplified difference; a PWM comparator which compares an output of the error amplification circuit with an output of a triangular wave oscillation circuit, and controls an output transistor; an overcurrent detection circuit monitors a load current flowing through a load connected to an output terminal via a sense resistor through which the load current flows, detects an overcurrent generated from the load current, and outputs an overcurrent detection signal causing a switching operation to stop; and a negative feedback control circuit which receives the overcurrent detection signal, and, while the overcurrent condition is detected, controls and holds the load current to a predetermined current value greater than zero until the overcurrent condition is removed.