A89331: Three Phase Sensorless Fan Driver

The A89331 three phase motor driver incorporates Sensorless sinusoidal drive to minimize vibration for high speed server fans. Sensorless control eliminates the requirement for hall sensors for server Fan applications.

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. This eliminates the requirement for a microprocessor based system and minimizes programming requirements.

The A89331 is available in a 28L 5x5 QFN with exposed power pad, (suffix ET), and a 20L TSSOP with exposed power pad (suffix LP).

• Closed Loop Speed Control
• Overvoltage Protection
• Power Loss Brake
• Fault Mode Brake
• Configurable RD or FG Output
• Speed Curve Configuration via EEPROM
• I2C Serial port
• Sinusoidal modulation for Reduced Audible Noise and Low vibration
• Sensorless (No Hall Sensors required)
• Trapezoidal Drive Option for High Speed
• Low RDSON Power MOSFETs – 3A capability
• Minimal External Components
• PWM Duty Cycle Speed Input
• FG Speed Output
• Lock Detection
• Soft Start
• Shorted Load Protection