AH293 LOW VOLTAGE HALL-EFFECT SMART FAN MOTOR CONTROLLER Description Pin Assignments AH293 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 RD shutdown, and recovery protections. Also, rotor-state 5 detection (RD) output is for speed detection. 293 GND 2 Rotor-lock shutdown detection circuit turns off the output driver when the rotor is blocked to avoid coil overheat. Then, the automatic recovery circuit will restart the motor. These DO 3 74 DOB protected actions are repeated and periodic during the blocked period. Until the blocking is removed, the motor SOT89-5L recovers and runs normally. The AH293 is available in SOT89-5L package. Features Applications Two-coil BLDC cooling fans On Chip Hall Sensor Low to medium voltage, low power BLDC motors Rotor-Locked Shutdown Automatically Restart Rotor-State Detection (RD) Output Built-in Zener Protection for Output Driver Operating Voltage: 1.8V~5.75 V Output Current: I = 400 mA O(AVE) Packaged in SOT89-5L Green Molding Compound Typical Application Circuit (Note 1) D2 V dd (1.8V/5.75V) R pu 293 D1 Coil2 Coil1 1 2 3 4 5 GND RD (alarm) C3 R1 R2 Notes: 1. R1, R2: typical 56 Ohm C1, C2, C3: typical 2.2F C1 C2 The R, C value need to be fine tuned based on coils design. 1.8V/5.75V DC Brush-Less Fan with RD Output Function 1 of 8 June 2010 AH293 Diodes Incorporated www.diodes.com Document number: DS31048 Rev. 6 - 2 AH293 LOW VOLTAGE HALL-EFFECT SMART FAN MOTOR CONTROLLER Pin Descriptions Pin Name Description RD Rotor-State Detection 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 RD 2 of 8 June 2010 AH293 Diodes Incorporated www.diodes.com Document number: DS31048 Rev. 6 - 2