Integrated circuit for driving liquid crystal

摘要

A liquid crystal driving integrated circuit capable of adjusting display contrast and requiring no externally attached components. Transmission gates TG0-TG10 are provided at respective connection points of twelve resistor elements connected in series between a power supply and the ground. One of the voltages V0-V10 derived from the transmission gates TG0-TG10 in accordance with control signals CA0-CA10 is applied to an operational amplifier 8, and used as a reference voltage VLCD0. The control signals CA0-CA10 are obtained by decoding control data D0-D3 supplied from an external source by a decoder 19. Therefore, the reference voltage VLCD0 can be set in a plurality of stages simply by changing control data D0-D3 to a user specified value. As the twelve resistor elements connected in series are formed on the same semiconductor substrate, display contrast can be adjusted without requiring any external components attached to a liquid crystal driving integrated circuit 1. <IMAGE>