A liquid crystal driving integrated circuit capable of adjusting display
contrast and requiring no externally attached components. A resistor
formed by four serially connected resistor elements R1 has one end
connected to a reference voltage VLCD0 applied from an operational
amplifier 8, and the other end connected to an external variable resistor
25 through a terminal 24. Consequently, liquid crystal driving voltages
VLCD0, VLCD1, VLCD2, VLCD3, and VLCD4 can be finely adjusted not only by
eleven versions of reference voltage VLCD0 in accordance with voltages at
respective connection points of twelve serially connected resistor
elements, but by changing the resistance of the external variable resistor
25, to thereby provide a liquid crystal driving integrated circuit 1 that
can be used for a variety of general purposes. Since only one external
variable resistor 25 is required and this resistor is inherently variable,
there is no need to consider variation in characteristics.