초록 ▼

A power supply circuit includes a reference voltage generation circuit to generate reference voltages, an operational amplifier to receive a first reference voltage and an intermediate voltage, an operational amplifier to receive a second reference voltage and the intermediate voltage, an output buf

A power supply circuit includes a reference voltage generation circuit to generate reference voltages, an operational amplifier to receive a first reference voltage and an intermediate voltage, an operational amplifier to receive a second reference voltage and the intermediate voltage, an output buffer which includes a pair of transistors controlled to turn on/off according to outputs of the two operational amplifiers and generates the intermediate voltage, and a through current prevention circuit to prevent a through current supplied to the pair of transistors in the output buffer. The through current prevention circuit operates to turn off one of the pair of transistors when the other turns on. Thus, the through current in the pair of transistors can be prevented.

대표청구항 ▼

[ What is claimed is:] [7.]7. A liquid crystal display device, comprising:a liquid crystal panel including a plurality of pixels;a drive circuit to drive said liquid crystal panel; anda power supply circuit to generate an intermediate voltage between a power supply voltage applied to a power supply

[ What is claimed is:] [7.]7. A liquid crystal display device, comprising:a liquid crystal panel including a plurality of pixels;a drive circuit to drive said liquid crystal panel; anda power supply circuit to generate an intermediate voltage between a power supply voltage applied to a power supply node and a ground voltage applied to a ground node and supply the intermediate voltage to said drive circuit,said power supply circuit includinga reference voltage generation circuit to generate a reference voltage which defines an acceptable fluctuation range of said intermediate voltage,a voltage comparison circuit to compare said intermediate voltage and said reference voltage and output the comparison result,a pair of switches connected between said power supply node and a voltage output node from which said intermediate voltage is output and between said ground node and said voltage output node and controlled to turn on/off according to the output of said voltage comparison circuit, anda through current prevention circuit to prevent a through current caused between said power supply node and said ground node through said pair of switches.