Each full-bridge output is rated up to 1A and 18V. This driver includes fixed off-time pulse-width modulation (PWM) current regulators, along with 2-bit nonlinear DACs that allow stepper motors to be controlled in full, half, and quarter steps, and DC motors in forward, reverse, and coast modes. The PWM current regulator uses Allegro’s mixed decay mode for reduced audible motor noise, increased step accuracy, and reduced power dissipation.
Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation. Protection features include thermal shutdown with hysteresis, undervoltage lockout (UVLO) and crossover-current protection. Special power-up sequencing is not required.
The AMT49701 is supplied in an EV package, a 6 × 6 mm, 36-pin QFN package with a nominal overall package height of 0.90 mm, and with an exposed thermal pad.