AH286
HALL-EFFECT SMART FAN MOTOR CONTROLLER
Description
Pin Assignments
The AH286 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.
(Top View)
Vdd
1
2
RD
5
286
GND
To help protect the motor coils, the AH286 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 Rotor-lock Detect (RD) output flag allows
external monitoring of any motor locks.
DO 3
7
4
DOB
SOT89-5L
The AH286 is available in SOT89-5L package.
Features
Applications
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Single-chip solution
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Two-coil BLDC cooling fans
Low to medium voltage, low power BLDC motors
Operating Voltage: 3.8V to 20V
Built-in Hall sensor and input amplifier
Rotor-lock Detect (RD) flag
Rotor Lock Protection (Lock detection, output shutdown
and automatic re-start)
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Built-in Zener protection for output driver
Average output current up to 500mA
Packaged in SOT89-5L
Green Molding Compound
Typical Application Circuit
D2
Vdd
(12V)
Rpu
D1
5
1
4
Coil2
RD
286
Coil1
2
3
D3
C3
R1
C1
R2
C2
GND
12V DC Brush-Less Fan with RD Output Function
Notes: 1. Typically it is recommended to us a 56 Ohm resistor for R1 and R2 and a 2.2μF E-Cap capacitor for C1, C2 and C3. These values
may need to be optimized depending on the coils used.
To help with IC protection it’s advised to add a Zener diode between Vdd and ground. The Zener diode should be chosen to help
prevent the supply voltage exceeding the maximum rating of the device.
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www.diodes.com
June 2010
© Diodes Incorporated
AH286
Document number: DS31030 Rev. 12 - 2