The A3908 is a low voltage bi-directional DC motor driver, with a typical input voltage range of 3 to 5.5 V and output currents up to 500mA. Its extremely small 2 mm x 2 mm package, relative high output current, adjustable linear constant motor voltage control, very low standby current, and wide operating input voltage range make it a perfect choice for portable DC motor or voice coil applications.

The A3908 is part of Allegro® low voltage motor driver family that includes the A3901 DC and stepper motor driver, A3903 DC motor driver, A3904 8-bit voice coil motor driver, and A3906 dual DC and stepper motor driver. The A3908 is similar to the A3903 but has lower input voltage logic thresholds.

The unique output full-bridge incorporates sourceside linear operation to allow a constant voltage across the motor coil. This regulated output minimizes motor voltage change due to I × RDS(on) variation and battery voltage tolerance. Logic input pins are provided to control the motor direction of rotation, brake, and standby (< 500 nA standby current) modes and to allow optional PWM-ing of the sink drivers. Internal protection circuitry includes thermal shutdown, undervoltage lockout, and crossover current (shoot-through) protection.

The A3908 is supplied in a 2 mm x 2 mm, 0.55 mm nominal height, 8-lead DFN package, with exposed thermal pad (package suffix EE). This small footprint package is lead (Pb) free, with 100% matte tin leadframe plating.