A4975
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 thermal shutdown circuitry
▪ Crossover-current and UVLO protection The A4975 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
necessary for microstepping. Microstepping provides increased
step resolution, and reduces torque variations and resonance
problems at low speed. PACKAGES: Package B, 16-pin DIP
with exposed tabs Internal circuitry determines whether the PWM current control
circuitry operates in a slow (recirculating) current decay mode,
fast (regenerative) current decay mode, or in a mixed current
decay mode in which the off-time is divided into a period of
fast current decay and with the remainder of the fixed off-time …