A stepping motor driving apparatus includes a detector that detects a
current supplied to a winding included in the stepping motor, a first
offset adding section that adds an offset to the output of the detector,
an amplifier that amplifies the output of the first offset adding
section, a reference signal generator that generates a reference signal
indicating a current limit, a second offset adding section that adds an
offset to the output of the reference signal generator, a switching
section that supplies a power to the winding when the switching section
is turned on and cuts off a power to the winding when the switching
section is turned off, and a PWM controller that turns on the switching
section every predetermined period, and turns off the switching section
when the output of the amplifier exceeds the output of the second offset
adding section.