A3980: Automotive DMOS Microstepping Driver with Translator

These parts are in production but have been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of this device is currently restricted to existing customer applications. The device should not be purchased for new design applications because obsolescence in the near future is probable. Samples are no longer available. Date of status change: November 17, 2011.

Recommended Substitutions: For existing customer transition, and for new customers or new applications, refer to the A3981.


The A3980 is a complete microstepping motor driver with built-in translator for easy operation. It is designed to operate bipolar stepper motors in full-, half-, eighth-, and sixteenthstep modes, at up to 35 V and 1 A. The A3980 includes a fixed off-time current regulator which has the ability to operate in slow, fast, or mixed decay modes. This results in reduced audible motor noise, increased step accuracy, and reduced power dissipation.

The translator is the key to the easy implementation of the A3980. Simply inputting one pulse on the step input drives the motor one microstep. There are no phase sequence tables, high frequency control lines, or complex interfaces to program. The A3980 interface is an ideal fit for applications where a complex P is unavailable or overburdened.

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

Internal circuit protection includes: thermal shutdown with hysteresis, overvoltage lockout (OVLO), undervoltage lockout (UVLO), and crossover current protection. Special power-up sequencing is not required. In addition, two diagnostic fault flags provide indication of shorts or opens on the motor windings.

The A3980 is supplied in a low-profile (1.1 mm) 28L TSSOP with exposed thermal pad. This device is available also in a lead-free version (leadframe plating 100% matte tin).

Top Features

  • Typical application up to ±1 A, 35 V output rating
  • Low RDS(ON) outputs, 0.67 Ω source, 0.54 Ω sink typical
  • Automatic current decay mode detection/selection
  • 3.0 V to 5.5 V logic supply voltage range
  • Mixed, fast, and slow current decay modes
  • Synchronous rectification for low power dissipation
  • Internal OVLO, UVLO, and thermal shutdown circuitry
  • Crossover current protection
  • Short to supply/ground and short/low load current diagnostics

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A3980KLPTR-T 28-lead TSSOP -40°C to 125°C Yes View Data Not for new design Contact your
local sales rep
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.


The A3980 is supplied in a low-profile (1.1 mm) 28L TSSOP with exposed thermal pad (suffix LP). This device is available also in a lead-free version (leadframe plating 100% matte tin).

LP-eTSSOP 24 lead