General Description
AH291 is a monolithic fan motor controller with Hall sensor’s capability. It contains two complementary open-collector drivers for motor’s coil driving, automatic lock shutdown and restart function relatively.
To avoid coil burning, rotor-lock shutdown detection circuit shut down the output driver if the rotor is blocked and then the automatic recovery circuit will try to restart the motor. These protecting actions are repeated and periodic during the blocked period. Until the blocking is removed, the motor recovers running normally.

Features
- On chip Hall sensor
- Rotor-locked shutdown
- Automatically restart
- Built-in Zener protection for output driver
- Operating voltage: 1.8V~5.75 V
- Output current: IO(AVE) = 400 mA
- Package: SIP-4L, SOT23-5L, SOT89-5L