In a semiconductor integrated circuit device, having a pair of voltage step-down
power supply circuits for active and standby conditions, a first reference voltage
is formed by amplifying a fixed voltage formed in a fixed voltage generating circuit
with an amplifying circuit which can adjust the voltage gain having a resistance
circuit and a switch controlled with a first trimming switch setting signal. An
internal step-down voltage, when the internal circuit is in the active condition,
is outputted from a first output buffer, which is activated with a first control
signal. A second reference voltage is formed by adjusting a combination of threshold
voltages of MOSFETs and a switch controlled with a second trimming switch setting
signal; and, an internal step-down voltage, when the internal circuit is in the
standby condition, is outputted with a second output buffer, which is activated
with a second control signal.