INTEGRATED CIRCUIT FOR DRIVING LIQUID CRYSTAL

摘要

PROBLEM TO BE SOLVED: To eliminate the necessity of externally mounted parts while having a display contrast adjusting function. SOLUTION: A transmission gate is provided at each of the connection points of serial resistors. Any one of the voltages led from the transmission gates in accordance with control signals CA0 to CA10 is used as a reference voltage through an operational amplifier. The signals CA0 to CA10 are obtained by decoding the values of externally supplied control data D0 to D3 in a decoder 19. Thus, the reference voltage is set in plural steps by merely changing the data D0 to D3 to the values instructed by a user. In other words, display contrast is adjusted without providing externally mounted parts to an integrated circuit for driving liquid crystal.