A3955
Full-Bridge PWM Microstepping Motor Driver Discontinued Product
This device is no longer in production. The device should not be
purchased for new design applications. Samples are no longer available. Date of status change: January 30, 2012 Recommended Substitutions: For existing customer transition, and for new customers or new applications, refer to the A4975. NOTE: For detailed information on purchasing options, contact your
local Allegro field applications engineer or sales representative.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, revisions to the anticipated product life cycle plan
for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The
information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use. A3955
Full-Bridge PWM Microstepping Motor Driver
Features and Benefits Description ▪ ±1.5 A continuous output current
▪ 50 V output voltage rating
▪ Internal PWM current control
▪ 3-bit nonlinear DAC
▪ Fast, mixed fast/slow, and slow current-decay modes
▪ Internal transient-suppression diodes
▪ Internal thermal shutdown circuitry
▪ Crossover-current and UVLO protection The A3955 is designed to drive one winding of a bipolar
stepper motor in a microstepping mode. The outputs are
rated for continuous output currents to ±1.5 A and operating
voltages to 50 V. Internal pulse width modulated (PWM) current
control combined with an internal three-bit nonlinear digitalto-analog converter allows the motor current to be controlled
in full-, half-, quarter-, or eighth-step (microstepping) modes.
Nonlinear increments minimize the number of control lines …