A3918: Low Voltage DC Motor Driver


Designed for pulse width modulated (PWM) control of a low voltage DC motor, the A3918 is capable of output currents up to 1.5 A and operating voltages from 2.5 to 9 V.

The A3918 has an internal fixed off-time PWM timer that sets a peak current based on the selection of a current sense resistor. An overcurrent output flag is provided that notifies the user when the current in the motor winding reaches the peak current determined by the sense resistor. The fault output does not affect driver operation.

The A3918 is provided in a 16-contact, 3 mm × 3 mm, 0.75 mm nominal overall height QFN, with exposed pad for enhanced thermal dissipation. It is lead (Pb) free, with 100% matte tin leadframe plating.

Applications include the following:

  • Digital still cameras (DSC)
  • Cell phone cameras
  • USB powered devices
  • Battery powered devices

Top Features

  • 2.5 to 9 V operation
  • Internal PWM current control
  • Synchronous rectification for reduced power dissipation
  • Peak current output flag
  • Undervoltage lockout
  • Low RDS(on) outputs
  • Small package
  • Brake mode for DC motor
  • Sleep function
  • Crossover-current protection
  • Thermal shutdown

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A3918SESTR-T 16-lead QFN -20°C to 85°C Yes View Data Contact your
local sales rep
Distributor Stock
APEK3918SES-01-T DEMO BOARD -20°C to 85°C No -- 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.