Allegro MicroSystems A3974SED DMOS Dual Full-Bridge PWM Motor Driver Datasheet

The A3974SED is a dual full-bridge PWM motor driver designed for pulse-width modulated (PWM) current control of two dc motors. It can output ±1.5 A current and operate at up to 50 V. The 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. Independent ENABLE input terminals are provided for use in controlling the speed and torque of each dc motor with externally applied PWM control signals. Synchronous rectification circuitry allows the load current to flow through the low rDS(on) of the DMOS output driver during the current decay. This feature will eliminate the need for external clamp diodes in most applications, saving cost and external component count, while minimizing power dissipation. Internal circuit protection includes thermal shutdown with hysteresis, undervoltage monitoring of VDD and the charge pump, and crossover-current protection. Special power-up sequencing is not required. The A3974SED is supplied in a 44-lead plastic PLCC with four copper batwing tabs for maximum heat dissipation. The power tabs are at ground potential and need no electrical isola- tion.


Allegro MicroSystems A3974SED DMOS Dual Full-Bridge PWM Motor Driver Datasheet - cover page
Brand
Allegro
Category
Other Electronics
Document type
Datasheet
Language
English
Pages
12
File format
PDF
File size
160 KB
Published
03 August, 2012
Updated
30 September, 2023
MD5 checksum
8D6165A53B7FD0C1AFFAD7ACE51FF8D0

About this manual

The A3974SED is a DMOS dual full-bridge PWM motor driver designed for pulse-width modulated current control of two DC motors. It supports 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

  • Absolute Maximum Ratings
  • Electrical Characteristics
  • Functional Block Diagram
  • Functional Description
  • Serial Interface
  • Word 0 Bit Assignments
  • Word 1 Bit Assignments
  • Synchronous Rectification
  • Internal Circuit Protection

Specifications

Output Current+1.5 A
Load Supply Voltage50 V
Package Type44-lead plastic PLCC

Frequently asked questions

What current decay modes are supported?

The device can operate in slow, fast, and mixed current-decay modes.

Does the device require external clamp diodes?

No, synchronous rectification circuitry eliminates the need for external clamp diodes in most applications.

What is the package type?

The A3974SED is supplied in a 44-lead plastic PLCC with four copper batwing tabs.

Download PDF (160 KB)

More Allegro Manuals


View all Allegro manuals →