Description
The AH285 is a single-chip solution for driving two-coil brushless direct current (BLDC) fans and motors. The device includes a Hall effect sensor, dynamic offset correction and two complementary open-drain output drivers with internal Zener diode protection.
To help protect the motor coils, the AH285 provides Rotor Lock Protection which shuts down output drives if rotor lock is detected. The device automatically re-starts when the rotor lock is removed.
A Tachometer output is provided by open-drain Frequency Generator
(FG) Pin which allows external interface to monitor motor rotation or speed. The FG output is the magnetic change frequency.
The AH285 is available in SOT89-5 package.

Features
• Single-chip Solution
• Operating Voltage: 3.8V to 20V
• Built-in Hall Sensor and Input Amplifier
• Tachometer (FG) Output
• Rotor Lock Protection (Lock detection, output shutdown and
   automatic re-start)
• Built-in Zener Protection for Output Driver
• Average Output Current up to 500mA
• Packaged in SOT89-5
• Green Molding Compound
• Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
• Halogen and Antimony Free. “Green” Device (Note 3)

Applications
• Two-coil BLDC Cooling Fans
• Low to Medium Voltage, Low Power BLDC Motors