A3904: Low Voltage Voice Coil Motor Driver


This part is discontinued. Samples are no longer available.

Date of status change: March 4, 2013.

Recommended Substitutions: For existing customer transition, and for new customers or new applications, contact Allegro Sales.

The A3904 is a voice coil motor (VCM) driver, with an I2C-compatible serial interface. Designed for camera autofocus and zoom applications, this high accuracy digital IC is provided in a WLCSP package ideal for portable devices. Its operating voltage range is 2.4 to 5.5 V, and its maximum output current is 127 mA.

Output current is programmed via the I2C interface, in 500 µA increments, with clock rates up to 400 kHz. I2C inputs set the internal D-to-A converter output voltage that is the reference for linear current control via a MOSFET output sink transistor. To conserve battery power, a logic low signal on the SLEEPZ input disables the output MOSFET and reduces the supply current to <0.5 µA.

A3904 internal protection features include thermal shutdown and undervoltage lockout. Logic input levels are independent of the supply voltage. The operating temperature range is –40°C to 85°C.

Top Features

  • Fixed I2C logic thresholds
  • 8-bit D-to-A converter
  • 500 µA resolution
  • Low voltage I2C serial interface
  • Low current-draw sleep mode
  • 2.4 to 5.5 V operation
  • 1.1 mm × 0.7 mm, 0.5 mm maximum overall height WLCSP

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A3904ECGTR 6-lead CSP -40°C to 85°C Yes View Data Discontinued 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 A3904 is available in a bumped wafer level chip scale package (WLCSP) (suffix CG).
PackageCG Chip Scale 6 bump