Overview
The STK672-110 is a unipolar fixed-current chopper type 2-phase stepping motor driver hybrid IC. It features power MOSFETs in the output stage and a built-in phase signal distribution IC. The incorporation of a phase distribution IC allows the STK672-110 to control the speed of the motor based on the frequency of an external input clock signal. It supports two types of excitation for motor control: 2-phase excitation and 1-2 phase excitation. It also provides a function for switching the motor direction.

Features
• The motor speed can be controlled by the frequency of
   an external clock signal (the CLOCK pin signal).
• The excitation type is switched according to the state
   (low or high) of the MODE pin. The mode is set to
   2-phase or 1-2 phase excitation on the rising edge of the
   clock signal.
• A motor direction switching pin (the CWB pin) is provided.
• All inputs are Schmitt inputs and 40-kΩ
   (typical: –50 to +100%) pull-up resistors are built in.
• The motor current can be set by changing the Vref pin
   voltage. Since a 0.22-Ω current detection resistor is built
   in, a current of 1 A is set for each 0.22 V of applied
   voltage.
• The input frequency range for the clock signal used for
   motor speed control is 0 to 25 kHz.
• Supply voltage ranges: VCC1 = 10 to 42 V, VCC2 = 5.0 V ±5%
• This IC supports motor operating currents of up to 1.8 A
   at Tc = 105°C, and of up to 2.65 A at Tc = 25°C.
  
Applications
• Two-phase stepping motor drive in send/receive
   facsimile units
• Paper feed in copiers, industrial robots, and other
   applications that require 2-phase stepping motor drive