FEATURES AND BENEFITS

• 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 Rds(on) power MOSFETs – 3 A capability

• PWM duty cycle speed input

• FG speed output

• Lock detection

• Soft start

• Shorted load protection

APPLICATIONS

• High-speed 12 V server cooling fans

• Industrial and consumer blowers and fans

DESCRIPTION

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 28-lead 5 mm × 5 mm QFN with

exposed power pad (suffix ET), and a 20-lead TSSOP with

exposed power pad (suffix LP)