Semiconductor integrated circuit for regulator

摘要

A semiconductor integrated circuit for a regulator, including: a control transistor; a control circuit; and a discharge circuit, wherein the discharge circuit includes: a constant current source circuit; a reference voltage generating circuit; a voltage comparator circuit; and a current amplification circuit, and wherein the control circuit is configured to control the control transistor in response to the control signal, and the discharge circuit is configured to operate the discharge transistor by the amplified current amplified by the current amplification circuit.

主权项

1. A semiconductor integrated circuit for a regulator, comprising:
a control transistor connected between an input terminal receiving a DC voltage and an output terminal; a control circuit controlling the control transistor such that an output voltage is constant in response to a potential difference between a feedback voltage corresponding to the output voltage and a predetermined reference voltage; and a discharge circuit provided with a discharge transistor which is connected between the output terminal and a reference potential point, the discharge transistor being turned on and off in response to an external control signal to withdraw a charge of a capacitor connected to the output terminal, wherein the discharge circuit includes:
a constant current source circuit operating with the DC voltage applied to the input terminal as a power source voltage, and generating or cutting off a constant current in response to the control signal;a reference voltage generating circuit generating a reference voltage for a comparison operation based on the constant current generated by the constant current source circuit;a voltage comparator circuit determining whether the output voltage is higher than the reference voltage; anda current amplification circuit outputting an amplified current of the constant current if the output voltage is higher than the reference voltage, and wherein the control circuit is configured to control the control transistor in response to the control signal, and the discharge circuit is configured to operate the discharge transistor by the amplified current amplified by the current amplification circuit.