Automotive Stepper Driver


A4993 Product Image


Top Features


The A4993 is a flexible microstepping motor driver with integrated phase current control and a built-in translator for easy operation. It is a single chip solution designed to operate bipolar stepper motors in full-, half-, quarter-, eighth-, and sixteenth-step modes with operating supply voltages range of 3.5V to 28V and ±1.4A per phase. In addition, the product is rated to withstand automotive transient up to 50V. At power-on, the A4993 is configured to drive most small stepper motors with simple STEP and DIRECTION input.

The current regulator operates with fixed frequency PWM and uses adaptive mixed current decay to reduce audible motor noise and increase step accuracy. EMI performance is enhanced with optional PWM frequency dithering mode. Integrated current sense resistors reduce the PCB footprint and BOM cost.

The current in each phase of the motor is controlled through a DMOS full-bridge using synchronous rectification to improve power dissipation. Internal circuits and timers prevent crossconduction and shoot-through when switching between highside and low-side drives.

The outputs are protected from short circuits, and features for low load current and stalled rotor detection assist are included. Chiplevel protection includes hot thermal warning, overtemperature shutdown, overvoltage and undervoltage lockout.

An SPI-compatible serial interface can be used to switch microstep resolution between step control inputs. It can also be used to configure several motor control parameters and diagnostic thresholds, and to control the motor directly. Detailed diagnostics are available on the serial data output.

The A4993 is supplied in a 20-pin TSSOP power package with an exposed thermal pad (package type LP). This package is lead (Pb) free with 100% matte tin leadframe plating.

  • Peak motor current up to 1.4 A at 28 V.
  • Low RDS(ON) outputs, 0.5 Ω source and sink typical
  • Continuous operation at high ambient temperature
  • 3.5 to 50 V supply operation
  • Adaptive mixed current decay
  • Synchronous rectification for low power dissipation
  • Internal overvoltage and undervoltage lockout
  • Hot warning and overtemperature shutdown
  • Crossover-current protection
  • Short-circuit, open-load diagnostics
  • Stall-detect features
  • Configurable through serial interface.


  • Automotive stepper motors
  • Engine management
  • Headlamp positioning
  • HVAC flap and valve control
20-pin TSSOP with exposed thermal pad (suffix LP)

Part Number Specifications and Availability