Sensorless BLDC Motor Driver with 165C Operation



Top Features


As automotive industry continues to improve efficiency, the market for BLDC fan drivers continue to grow. Requirements for low audible noise as the result of electrification is critical to driver experience. The A89304 three phase motor driver IC incorporates sensorless sinusoidal drive to minimize audible noise and vibration for a wide variety of fan applications. Specifically designed for environments with high ambient temperature the 89304 can operate up to 165C junction and can provide CPU cooling in the harshest of environments.

Sensorless control eliminates the requirement for Hall sensors. The A89304’s sinusoidal algorithm is designed be easy to implement with no software programming. With a completely integrated flexible closed-loop speed control algorithm the A89304 can operate without a microprocessor. EEPROM is used to tailor the common functions of the fan speed curve to a specific application. Allegro’s proprietary algorithm includes Zero Torque Position Detection (ZTPD) and Automatic Phase Advance not only improve startup performance but also enhance motor efficiency at high speed.  

Offered in a small 5mm x 5mm and only requiring 5 external components, the 89304 solution reduces PCB space and can fit in fans with 30mm x 30mm dimension. The A89304 is available in a 28-contact 5 mm × 5 mm QFN with exposed thermal pad (suffix ET)

Featured Applications:

  • CPU/GPU Cooling for Automotive Vision Systems
  • Birds Eye Vision
  • Lidar Cooling
  • HUD Cooling Fan
  • LED Headlamp Cooling
  • AEC-Q100 Grade 0 qualified
  • Speed curve configuration via EEPROM
  • I2C serial port
  • Sinusoidal modulation for reduced audible noise and low vibration
  • Sensorless (no Hall sensors required)
  • Low RDS(ON) power MOSFETs
  • 3.3 V / 20 mA linear regulator
  • PWM or analog speed input
  • FG speed output
  • Slew rate control
  • Lock detection Soft start
  • Low power standby mode
  • Overcurrent protection
  • Overvoltage protection

28-contact QFN with exposed thermal pad and wettable flank 5mm x 5 mm x 0.90 mm (ET package)

Part Number Specifications and Availability