AH292 LOW VOLTAGE HALL-EFFECT SMART FAN MOTOR CONTROLLER Description Pin Assignments AH292 is a monolithic fan motor controller with Hall sensors (Top View) capability. It contains two complementary open-collector transistors for motors coil driving, automatic lock current Vdd 1 FG 5 shutdown, and recovery protections. In addition a Frequency generator (FG) output is also available for speed detection. 292 GND 2 Rotor-lock shutdown detection circuit turns off the output driver when the rotor is blocked to avoid coil overheat. Then, DO 3 74 DOB the automatic recovery circuit will restart the motor. These protected actions are repeated and periodic during the SOT89-5L blocked period. Until the blocking is removed, the motor recovers and runs normally. The AH292 is available in SOT89-5L package. Applications Features Two-coil BLDC cooling fans On Chip Hall Sensor Low to medium voltage, low power BLDC motors Rotor-Locked Shutdown Automatically Restart Frequency Generator (FG) Output Built-in Zener Protection for Output Driver Operating Voltage: 1.8V to 5.75V Output Current: I = 400mA O(AVE) Packaged in SOT89-5L Green Molding Compound Typical Application Circuit (Note 1) D2 Vdd (1.8V/5.75V) Rpu 292 D1 Coil 2 Coil 1 1 2 3 4 5 GND FG R1 R2 C3 Notes: 1. R1, R2: typical 56 Ohm C1 C2 C1, C2, C3: typical 2.2F The R, C value need to be fine tuned based on coils design. 1.8V/5.75V DC Brush-less Fan with FG output function 1 of 8 June 2010 AH292 Diodes Incorporated www.diodes.com Document number: DS31049 Rev. 7 - 2 AH292 LOW VOLTAGE HALL-EFFECT SMART FAN MOTOR CONTROLLER Pin Descriptions Pin Name Description FG Frequency Generation Vdd Input Power DO Output Pin DOB Output Pin GND Ground Functional Block Diagram Vdd Lock detect, shutdown and automatic re-start Regulator DO Hall Plate Control Logic Amp. DOB GND FG 2 of 8 June 2010 AH292 Diodes Incorporated www.diodes.com Document number: DS31049 Rev. 7 - 2