Three-Phase Sensorless Fan Driver

   The A4942 three phase motor driver incorporates BEMF sensing to eliminate the requirement for Hall sensors in fan applications.
   A closed loop speed control system is integrated into the IC. This allows accurate setting of maximum and minimum speeds via selection of external resistors. The speed is controlled by duty cycle demand applied to the PWM input.
   The PWM input is allowed to operate over a wide frequency range.

FEATURES & BENEFITS
◾ Sensorless (no Hall sensors required)
◾ Closed loop speed control
◾ Minimal external components
◾ PWM speed input
◾ FG speed output
◾ Lock detection
◾ Soft start
◾ Overcurrent protection
◾ Soft switching for reduced audible noise