VOLTAGE SUPPLY DEVICE, AND SEMICONDUCTOR DEVICE USING THE VOLTAGE SUPPLY DEVICE, ELECTRO-OPTICAL DEVICE AND ELECTRONIC EQUIPMENT LISING THE SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a voltage supply device capable of highly accurately and quickly obtaining necessary charging voltage without requiring any offset cancel circuit. ;SOLUTION: The voltage supply device supplies voltage to a load capacitor to charge the load capacitor with prescribed voltage within a prescribed charging period. The voltage supply device is provided with a DAC 70, a voltage follower circuit 72 for converting voltage from the DAC 70 into impedance and outputting the impedance to a 1st switching element Q1 connected between the circuit 72 and the load capacitor, a by-pass line 205 for supplying the voltage from the DAC 70 directly to the load capacitor without passing the circuit 72 and the element Q1, and a 2nd switching element Q2 connected to the way of the by-pass line 205. In the first half period of the charging period, voltage output is switched to an output only from the circuit 72 by turning on the element Q1 and turning of the element Q2, and in the latter half period, the voltage output is switched to an output only from the DAC 70 by turning off the element Q1 and turning on the element Q2.;COPYRIGHT: (C)2001,JPO