Allegro’s A5988 quad DMOS full-bridge driver

Allegro MicroSystems, LLC unveils its new quad DMOS full-bridge driver IC capable of driving up to two stepper motors or four DC motors. Each full-bridge output is rated up to 1.6 A and 40 V. The A5988 includes fixed off-time pulse-width modulation (PWM) current regulators, along with 2- bit nonlinear DACs (digital-to-analog converters) 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 the Allegro™ patented mixed decay mode for reduced audible motor noise, increased step accuracy, and reduced power dissipation. This new 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 6 mm × 6 mm, 36-pin QFN package with a nominal overall package height of 0.90 mm. The JP is a 7 mm × 7 mm 48-pin LQFP. Both packages are lead (Pb) free, with 100% matte-tin leadframe plating.