November 21, 2017
Allegro MicroSystems, LLC introduces a new quad DMOS full-bridge driver capable of driving up to two stepper motors or four DC motors. The AMT49701 was designed specifically for dual axis, point of sale, office automation, security, surveillance, IP cameras, as well as industrial automation applications.
Each full-bridge output is rated up to 1 A and 18 V. This new driver 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.
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 mm × 6 mm, 36-pin QFN package with a nominal overall package height of 0.90 mm, and with an exposed thermal pad for enhanced thermal performance. The package is lead (Pb) free, with 100% matte-tin leadframe plating.