The SPINx1A is a one channel isolated digital potentiometer intended for spindle control. The SPINx1A takes three TTL level signals,PWM, DIR and ENA and has four isolated outputs: CW, CCW, ENA and VOUT.  VOUT is a Analog voltage proportional to the PWM input signal and the Analog reference voltage (5 to 21 VDC). The SPINx1A is an improved version of the SPINX1 with better linearity, constant analog current draw vs PWM duty cycle, and a wider analog voltage range (5V to 21V)