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)