Allegro MicroSystems Announces A4941, New Three-Phase Sensorless Fan Driver IC
Allegro MicroSystems Announces A4941, new three-phase, sensorless, brushless DC motor driver IC to complement their existing family of brushless DC devices. The A4941 motor driver offers sensorless commutation, a wide supply voltage range, 1.25 A peak output current, -40°C to 105°C operating temperature range, lock detection with auto restart, and a small eTSSOP package with soft switching for reduced audible noise. This new device is targeted at the consumer white goods and office automation markets with key fan applications used in refrigerators and air purifiers.
The A4941 motor driver system consists of three half bridge NMOS outputs, BEMF sensing circuits, adaptive commutation control, and state sequencer. The sequencer determines which output devices are active. The BEMF sensing circuits and adaptive commutation circuits determine when the state sequencer advances to the next state.
The A4941GLP-T is supplied in a 16 lead TSSOP package with ex¬posed power tab. The package is lead (Pb) free, with 100% matte tin leadframe plating.

A4941 – Three-Phase Sensorless Fan Driver IC
(Photo from Aleggro Website)
More information about Sensorless Fan Driver IC can be found at Allegro Microsystems Website
