Low-Voltage Coil Driver Suits Camera Optics

Allegro’s A3904 is the first device in a series of voice coil motor drivers with an I²C serial interface designed for camera auto focus and zoom applications. The operating voltage range is 2.4 V to 5.5 V, and the 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 also set the internal DAC output voltage used as a reference for linear current control using a MOSFET as an output-sink transistor.

A logic-low state on the SLEEPZ input will put the A3904 into sleep mode and reduce the supply current to less than 0.5 µA. Packaging options are a six-contact DFN (suffix EW) with a 0.38-mm profile and exposed tab for enhanced thermal dissipation; a bare die form on wafer (suffix CW); and a six-ball wafer-level chip scale (WLCSP) bumped package (suffix CG). Pricing is $0.57 in quantities of 1000.