The STK672-642AN-E is a hybrid IC for use a unipolar, 2-phase stepper motor driver with PWM current control. It includes a built-in controller and is based on a unipolar constant-current PWM system. The STK672-642AN-E supports application simplification and standardization by providing a built-in 4 phase distribution stepping motor controller. It supports five excitation methods: 2 phase and 1-2 phase excitations, and can provide control of the basic stepping angle of the stepper motor divided into 1/2 step units. It also allows the motor speed to be controlled with only a clock signal. The use of this hybrid IC allows designers to implement systems that provide high motor torques, low vibration levels, low noise, fast response, and high-efficiency drive. In addition the STK672-642AN-E has protective function against over-current and over-heat. And STK672-640AN-E with hole to attach a heat-sink is lined up.