The A5988 from Allegro includes fixed off-time PWM current regulators, along with 2bit nonlinear DACs that enable stepper motors to be controlled in full, half and quarter steps, and DC motors.
Allegro MicroSystems has introduced a quad DMOS full-bridge driver IC that can drive up to two stepper motors or four DC motors. The A5988 has full-bridge output that is each rated up to 1.6A and 40V, and includes fixed off-time pulse-width modulation (PWM) current regulators, along with 2bit nonlinear DACs that enable 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 the Allegro patented mixed decay mode for reduced audible motor noise, increased step accuracy and reduced power dissipation, the company noted. This device is targeted at the consumer and office automation markets with end applications to include closed circuit TV (pan and tilt) applications, scanners, POS, laser, inkjet and label printers.
Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation. A low power sleep mode is included to reduce power dissipation. Protection features include thermal shutdown with hysteresis, undervoltage lockout (UVLO) and crossover-current and over-current protection. Special power-up sequencing is not required.
The A5988 is supplied in two packages, EV and JP, with exposed power tabs for enhanced thermal performance. The EV is a 6mm x 6mm, 36-pin QFN package with a nominal overall package height of 0.90mm. The JP is a 7mm x 7mm 48-pin LQFP. Both packages are lead (Pb) free, with 100% matte-tin leadframe plating.