feature a DMOS H-bridge that handles continuous currents of ±2 A and operating voltages to 50 V. The DMOS output transistors have low RDS(ON) rating and are synchronously rectified during PWM operation for low power dissipation. The A3958SB and A3958SLB from Allegro Microsystems Inc., Worcester, Mass., are controlled through a three-wire serial port for configuring the internal PWM current-control circuitry to match the motor-driving requirements. Fast, slow, and mixed current-decay modes and current sense comparator blank time are programmable through the serial port. Internal circuit protection includes thermal shutdown with hysteresis, crossover-current protection, and undervoltage lockout circuitry. The A3958SB comes in a 24-pin DIP and the A3958SLB comes in a 24-lead SOIC package.
