A4986: DMOS Dual Full-Bridge PWM Motor Driver with Overcurrent Protection

Description

The A4986 is a dual DMOS full-bridge stepper motor driver with parallel input communication and overcurrent protection. Each full-bridge output is rated up to 35 V and ±2 A.

The A4986 includes fixed off-time pulse width modulation (PWM) current regulators, along with 2- bit nonlinear DACs (digital-to-analog converters) that allow stepper motors to be controlled in full, half, and quarter steps. The PWM current regulator uses the Allegro patented mixed decay mode for reduced audible motor noise, increased step accuracy, and reduced power dissipation.

Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation.

The outputs are protected from shorted load and short-toground events, which protect the driver and associated circuitry from thermal damage or flare-ups. Other protection features include thermal shutdown with hysteresis, undervoltage lockout (UVLO) and crossover current protection. Special power-up sequencing is not required.

The A4986 is supplied in a 24-contact QFN package (ES), and a 24-pin TSSOP package (LP) with an overall package height of ≤1.2 mm. Both packages have exposed pads for enhanced thermal dissipation, and are lead (Pb) free (suffix –T), with 100% matte tin plated leadframes.

Top Features

  • Low RDS(ON) outputs
  • Internal mixed current decay mode
  • Synchronous rectification for low power dissipation
  • Internal UVLO
  • Crossover-current protection
  • 3.3 and 5 V compatible logic supply
  • Thin profile QFN and TSSOP packages
  • Thermal shutdown circuitry
  • Short-to-ground protection
  • Shorted load protection
  • Low current Sleep mode, <10 µA

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Compliant
Part Composition /
RoHS Data
Comments Samples Check Stock
A4986SESTR-T 24-lead QFN -20°C to 85°C Yes View Data Contact your
local sales rep
Check
Distributor Stock
A4986SLPTR-T 24-lead TSSOP -20°C to 85°C Yes View Data Contact your
local sales rep
Check
Distributor Stock
APEK4986SLP-01-T DEMO BOARD -20°C to 85°C No -- Contact your
local sales rep
Check
Distributor Stock

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.

Packaging

The A4986 is supplied in a 24-contact QFN package (ES), and a 24-pin TSSOP package (LP) with an overall package height of ≤1.2 mm. Both packages have exposed pads for enhanced thermal dissipation, and are lead (Pb) free (suffix –T), with 100% matte tin plated leadframes.

 ES-QFN, ET-QFN, and LP-TSSOP Combined

Design Support Tools

A4986 Demo Board Schematics