Allegro A3988 Quad DMOS Full-Bridge PWM Motor Driver
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The A3988 is quad DMOS full-bridge driver capable of driving up to two stepper motors or four DC motors. Each full-bridge output is rated up to 1.2A and 36V.
The A3988 includes fixed off time pulse width modulation (PWM) current regulators along with two bit non-linear DAC's (digital to analog converters) that permit stepper motors to be controlled in full, half and quarter step and DC motors in forward, reverse and coast modes.
The PWM current regulator uses Allegro's 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. Industry standard PHASE, I0, I1 logic inputs are used to control each fullbridge so the A3988 can easily replace most existing drivers.
Protection features include thermal shutdown with hysteresis, under voltage lockout (UVLO) and crossover current protection. Special power up sequencing is not required.
The A3988 is supplied in two packages, EV and JP, with exposed power tabs for enhanced thermal performance. The EV is a 6 mm x 6 mm, 36 lead eQFN package with a nominal overall package height of 0.90 mm. The JP is a 7 mm x 7 mm, 48 lead eLQFP package. Both packages are lead (Pb) free, with 100% matte tin leadframe plating.
Features
- 36 V 1.2 A rating
- Four full-bridges to drive two stepper motors or up to four DC motors
-> Can drive multiple motors, DC or stepper, with a single IC - Small 36-lead eQFN package (6 x 6 x 0.9 mm) and 48-lead eLQFP package (7 x 7 x 1.4 mm)
-> Requires less board space than typical single or dual H-Bridge devices - Phase, I0, I1 interface
-> Industry-standard interface allows easy conversion to the A3988 - Synchronous rectification
-> Reduces power dissipation and can eliminate the need for expensive
-> Schottky diodes - Low Ron DMOS outputs
-> Reduces power dissipation, can achieve higher average output current due to the lower die temperature rise - Mixed decay
-> Improved microstepping accuracy, reduced audible noise
-> Allegro patented feature