Patent ID: 9071185
Filing Date: 2015-06-30
Classification: G04C,G04G,G05F,H02M,Y02B

Abstract:
1. A constant voltage circuit, the operation of which consumes less current by performing an intermittent operation at a predetermined interval and which outputs a constant voltage to an output terminal, the constant voltage circuit comprising: an output transistor connected to the output terminal; a differential amplifier circuit which controls a gate of the output transistor such that a voltage of the output terminal becomes a constant voltage; a first switch circuit connected between the differential amplifier circuit and the gate of the output transistor; a first holding circuit connected between the gate of the output transistor and the output terminal through a second switch circuit; and a second holding circuit connected between the gate of the output transistor and a power supply terminal through a third switch circuit, wherein the constant voltage circuit has: a first operation mode in which the differential amplifier circuit and the first switch circuit are intermittently operated by a first control signal, and the second switch circuit is turned on and the third switch circuit is turned off by a second control signal; and a second operation mode in which the differential amplifier circuit and the first switch circuit are turned on by the first control signal, and the second switch circuit is turned off and the third switch circuit is turned on by the second control signal.