Allegro A3972SB Dual DMOS Full-Bridge Microstepping PWM Motor Driver Datasheet

The A3972SB is a dual DMOS full-bridge micro-stepping PWM motor driver designed for pulse-width modulated (PWM) current control of bipolar microstepping stepper motors. It is capable of continuous output currents to ±1.5 A and operating voltages to 50 V. The driver features internal fixed off-time PWM current-control timing circuitry that can be programmed via a serial interface to operate in slow, fast, and mixed current-decay modes. The desired load-current level is set via the serial port with two 6-bit linear DACs in conjunction with a reference voltage. The six bits of control allow maximum flexibility in torque control for a variety of step methods, from microstepping to full-step drive. Load current is set in 1.56% increments of the maximum value. The driver also includes synchronous rectification circuitry, which allows the load current to flow through the low rDS(on) of the DMOS output driver during the current decay. This eliminates the need for external clamp diodes in most applications, saving cost and minimizing power dissipation. The driver features internal circuit protection, including thermal shutdown with hysteresis, transient-suppression diodes, and crossover-current protection. Special power-up sequencing is not required. The A3972SB is supplied in a 24-lead plastic DIP with a copper batwing power tab. The lead (Pb) free version has 100% matte tin leadframe plating.


Allegro A3972SB Dual DMOS Full-Bridge Microstepping PWM Motor Driver Datasheet - cover page
Brand
Allegro
Category
Motor
Document type
Datasheet
Language
English
Pages
13
File format
PDF
File size
507 KB
Published
03 August, 2012
Updated
28 September, 2023
Model
A3972SB
MD5 checksum
0931CBD0E315FBE87F3302AFEA549D82

About this manual

The A3972SB is a dual DMOS full-bridge microstepping PWM motor driver designed for pulse-width modulated (PWM) current control of bipolar microstepping stepper motors. It supports continuous output currents up to +1.5 A and operating voltages up to 50 V. The device features internal fixed off-time PWM current-control timing circuitry that can be programmed via a serial interface to operate in slow, fast, and mixed current-decay modes.

What's inside

  • Features
  • Absolute Maximum Ratings
  • Electrical Characteristics
  • Functional Description
  • Serial Interface
  • Word 0 Bit Assignments
  • Word 1 Bit Assignments
  • Oscillator Control
  • Synchronous Rectification
  • Idle Mode

Specifications

Load Supply Voltage15 to 50 V
Continuous Output Current+1.5 A
Junction Temperature+150°C
Logic Supply Voltage4.5 to 5.5 V
Package Type24-lead plastic DIP

Frequently asked questions

What is the maximum continuous output current?

The device is capable of continuous output currents to +1.5 A.

Can the current-decay mode be programmed?

Yes, internal fixed off-time PWM current-control timing circuitry can be programmed via a serial interface to operate in slow, fast, and mixed current-decay modes.

What is the maximum operating voltage?

The device supports operating voltages up to 50 V.

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