Quad full bridge motor driver IC

Jon Lawson

Solid State Supplies Ltd has added a quad DMOS full-bridge driver IC to its expansive portfolio of products relating to motion control.

Targeted at office automation, surveillance and consumer electronics implementation, the A5988 from Allegro MicroSystems is suitable to place on either 3.3V or 5V voltage rails. With a 1.6A rating for each of its full-bridge outputs and a maximum load supply of 40V, it has the capacity to simultaneously drive up to 4 DC motors, or alternatively two stepper motors.

The IC incorporates fixed off-time pulse-width modulation (PWM) current regulators (based on patented mixed decay mode technology), along with 2-bit non-linear digital-to-analogue converters (DACs). By utilising these elements, the IC can control stepper motors in full, half and quarter steps as required. Likewise it can control DC motors in forward, reverse and coast modes. The proprietary mixed decay mode technology employed by the PWM current regulators, as well as built-in synchronous rectification control circuitry, lead to marked reductions in audible motor noise compared to competing devices. In addition, the A5988 increases step accuracy and lowers power dissipation - thereby resulting in greater efficiency. As the device only consumes 100µA (typical) while in sleep mode, lower power operation is assured. Special power-up sequencing processes are not required.

Key applications for Allegro A5988 are security equipment, scanners, point of sales (PoS) units and a wide variety of printers (laser, inkjet, label, etc). An array of protection mechanisms have been included in this drive to ensure ongoing reliability is maintained. Among these are thermal shutdown, under-voltage lockout (UVLO), over-current and current cross-over protection. The device supports an operating temperature range of -40°C to 105°C. It is offered in 2 different package formats, both of which have exposed power tabs in order to deliver elevated levels of heat dissipation. The EV version has a low-profile 36-pin QFN package with a 6mm × 6mm footprint, while the JP version is 48-pin LQFP package covering 7mm × 7mm.