A4975: Full-Bridge PWM Microstepping Motor Driver

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 digital-to-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.

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 spent in slow current decay. The combination of user-selectable current-sensing resistor and reference voltage, digitally selected output current ratio; and slow, fast, or mixed current-decay modes provides users with a broad, variable range of motor control.

Internal circuit protection includes thermal shutdown with hysteresis, an undervoltage monitor, and crossover-current protection. Special power-up sequencing is not required. The A4975 is supplied in a choice of two power packages; a 16-pin dual-in-line plastic package with copper heat-sink tabs (suffix ‘B’), and a 16-lead plastic SOIC with internally fused pins (suffix ‘LB’). For both package styles, the thermally enhanced pins are at ground potential and need no electrical isolation. Both packages are lead (Pb) free, with leadframe plating 100% matte tin.

DATASHEETS
SAMPLE & BUY

Astrorep Inc. (Allegro and Sanken Semiconductors, Sanken Power Supplies)
141 John Street, Suite 300
Babylon, NY 11702
Phone: (631)422-2500
Fax: (631)422-2504
Web: www.astrorepinc.com
Email: donna.tweedy@astrorepinc.com

If this is not your local representative, find your local sales rep here.

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  • Features and BenefitsFeatures and Benefits
  • PackagingPackaging
  • Technical DocsTechnical Docs
  • NewsNews
  • ±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 supplied in a choice of two power packages; a 16-pin dual-in-line plastic package with copper heat-sink tabs (suffix ‘B’), and a 16-lead plastic SOIC with internally fused pins (suffix ‘LB’). For both package styles, the thermally enhanced pins are at ground potential and need no electrical isolation. Both packages are lead (Pb) free, with leadframe plating 100% matte tin.

Packages

 

Click the image to view larger
A4975 Functional Block Diagram

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Compliant
Part Composition /
RoHS Data
Comments Samples Check
Distributor Stock
A4975SB-T 16-lead DIP -20°C to 85°C Yes View Data Not for new design Contact your
local sales rep
Check Stock
A4975SLBTR-T 16-lead SOIC -20°C to 85°C Yes View Data Contact your
local sales rep
Check Stock

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