AH288

HIGH VOLTAGE HALL-EFFECT SMART FAN MOTOR

CONTROLLER

AH288 Rev. 12

1 of 9

APRIL 2010

DS31040

www.diodes.com

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On chip Hall sensor

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Rotor-locked shutdown

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Automatically restart

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Frequency generator (FG) output

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Built-in Zener protection for output driver

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Operating voltage: 3.8V~28V

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Lead Free Package: SOT89-5L (Note 1)

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SOT89-5L: Available in “Green” Molding Compound

(No Br, Sb)

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Lead Free Finish/RoHS Compliant (Note 2)

AH288 is a monolithic fan motor controller with Hall sensor’s

capability. It contains two complementary open-drain transistors

as motor coil drivers, automatic lock current shutdown, and

recovery protections. Additional, frequency generator (FG) output

is for speed detection relatively.

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 protected

actions are repeated and periodic during the blocked period. Until

the blocking is removed, the motor recovers and runs normally.

Typical Application Circuit

288

1

3

2

Vdd (24V)

Coil2

Coil1

FG

D2

D1

* Rpu : typical 10 Kohm

C1

5

4

48V

48V

GND

D3

Note: The optional Capacitor C1 and Diode D3 are for power stabilization. C1 is recommended to

value need to be fine tuned to optimize design for different coils and power suppliers .

24V DC Brush-less Fan with FG output function

Features

General Description