Stepping motor driver circuit

A stepping motor driver circuit, comprising:

• a first push-pull circuit including first and second transistors of the first and the second conduction types, respectively, connected in series and having a first output terminal at the mid-point between said first and second transistors;
• a second push-pull circuit including third and fourth transistors of the first and the second conduction types, respectively, connected in series and having a second output terminal at the mid-point between said third and fourth transistors;
• first and second driving circuits for driving said first and second push-pull circuits in opposite phases relative to each other, respectively;
• and
• first and second holding circuits each including a first constant-current source for setting a predetermined constant current, a constant-voltage source for supplying a predetermined reference voltage to set a holding voltage, and an amplifier circuit of the current feedback type for inputting the reference voltage and operating with the constant current, said first and second holding circuits driving said first and second push-pull circuits, respectively, so that the output voltage between said first and second output terminals may be reduced to the holding voltage when a predetermined load is held.