Trimming by disconnecting a fuse connected in parallel to a feedback resistor
of an amplifier circuit would cause a variation in voltage value due to a remaining
resistance component. A voltage generator circuit is provided therein with a D/A
converter circuit of an R-2R ladder resistor network type circuit. The D/A converter
circuit is provided with a first switch circuit to an eighth switch circuit, corresponding
to each bit, which are switched to set a digital value. Each switch circuit, which
is provided with a fuse for providing a fixed voltage value, allows the fuse to
be disconnected to fix the voltage value to a value obtained by inverting the initial
value. The setting circuit controls the switching operation of each switch circuit,
thereby simulating an electrical state of a fuse being disconnected before the
fuse is actually disconnected.