A3985 is a dual full-bridge gate driver suitable for driving a wide range of higher power industrial bipolar 2- phase stepper motors or 2-phase brushless dc motors. It can also be used to drive two individual torque motors or solenoid actuators. Motor power is provided by external N-channel power MOSFETs at supply voltages from 12 to 50 V. Full digital control is provided by two serially-accessible registers that allow programming of off-time, blank-time, dead-time, mixed decay ratios, synchronous rectification, master clock source selection, and division ratio and idle mode. All internal timings are derived from a master clock that can be generated on-chip or provided by an external clock such as the system clock of the master controller. A programmable divider allows for a wide range of external system clock frequencies. The internal fixed off-time PWM current-control timing is programmed via the serial interface to operate in slow, fast, and mixed current-decay modes. The desired load-current level and direction is set via the serial port with a direction bit and two 6-bit linear DACs in conjunction with a reference voltage. The seven bits of control allow maximum flexibility in torque control
