New Industry Products

40V Three-Phase Sensorless Sinusoidal Fan Driver IC Minimizes Vibration & Noise

March 01, 2019 by Scott McMahan

Allegro Microsystems has introduced the A5947 three-phase motor driver IC. The motor driver incorporates sensorless sinusoidal drive to minimize vibration for a wide variety of fan applications. Sensorless control eliminates the requirement for Hall sensors. A5947 features a highly efficient sinusoidal algorithm designed to meet the market demand for BLDC fan drivers while providing an easy to implement a code-free solution.

The A5947 motor driver can address a wide range of cooling fan systems including automotive seat ventilation, battery cooling, ADAS GPU/CPU and server/telecom cooling fans. A flexible closed-loop speed control system is integrated into the IC. EEPROM is used to tailor the common functions of the fan speed curve to a specific application.

The device has a built-in, full sinusoidal sensorless BLDC control algorithm and a programmable speed curve that eliminates the need for an external microcontroller and software development. The company's proprietary algorithm has Zero Torque Position Detection (ZTPD) and Automatic Phase Advance which the company created to improve startup performance and enhance motor efficiency at high speed.

According to Allegro, the motor driver includes multiple external components such as MOSFETs, thereby reducing PCB space.

  • AEC-Q100 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
  • 3.3V/20mA linear regulator
  • PWM or analog speed input
  • FG speed output
  • Slew rate control
  • Lock detection Soft start
  • Low-power standby mode
  • Over-current protection
  • Over-voltage protection