PART OBSOLETE – NO ALTERNATE PART
AH286
HALL-EFFECT SMART FAN MOTOR CONTROLLER
Description
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.
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.
The AH286 is available in SOT89-5 package.
Pin Assignments
(Top View)
Vdd
OBSOLETE – PART DISCONTINUED
1
2
286
5
RD
GND
DO
3
7
DOB
4
SOT89-5
Features
•
•
•
•
•
•
•
•
•
•
•
Single-chip Solution
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)
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
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
AH286
Document number: DS31030 Rev. 13 - 4
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June 2017
© Diodes Incorporated
PART OBSOLETE – NO ALTERNATE PART
AH286
Typical Application Circuit
(Note 4)
Vdd (12V)
D2
OBSOLETE – PART DISCONTINUED
D1 R
pu
RD
5
4
286
1
2
3
Coil2
Coil1
D3
C3
GND
R1
C1
R2
C2
12V DC Brush-Less Fan with RD Output Function
Notes:
4. 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.
Pin Descriptions
Pin Name
RD
Vdd
DO
DOB
GND
Rotor-state detection
Input power
Output pin
Output pin
Ground
Description
AH286
Document number: DS31030 Rev. 13 - 4
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PART OBSOLETE – NO ALTERNATE PART
AH286
Functional Block Diagram
Vdd
OBSOLETE – PART DISCONTINUED
Lock detect,
shutdown and
automatic re-start
Regulator
DO
Hall
Plate
Amp.
Control Logic
DOB
GND
RD
AH286
Document number: DS31030 Rev. 13 - 4
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PART OBSOLETE – NO ALTERNATE PART
AH286
Absolute Maximum Ratings
(T
A
= +25°
C)
Symbol
Vdd
Supply Voltage
Output Current
Power Dissipation
Storage Temperature
Maximum Junction Temperature
Thermal Resistance Junction to Case (Note 5)
I
O (AVE)
I
O (PEAK)
Characteristics
Rating
24
500
700
800
-55 to +150
+150
156
Unit
V
mA
mA
mW
C
C
C/W
OBSOLETE – PART DISCONTINUED
I
O
P
D
T
ST
T
J
θ
JA
T
A
T
J
Tc
JA
JC
Note: 5. θ
JA
should be confirmed with heat sink thermal resistance. If there is no heat sink contact, θ
JA
will almost be the same as θ
JC
.
Recommended Operating Conditions
Symbol
Vdd
T
A
Supply Voltage
Operating Ambient Temperature
Characteristic
Conditions
Operating
Operating
Min
3.8
-40
Max
20
+100
Unit
V
C
AH286
Document number: DS31030 Rev. 13 - 4
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PART OBSOLETE – NO ALTERNATE PART
AH286
Electrical Characteristics
(T
A
= +25° V
DD
= 12V, unless otherwise specified.)
C,
Symbol
Idd
Characteristics
Supply Current
Output Leakage Current
Rotor Lock Protection On Time
Rotor Lock Protection Off Time
Output Saturation Voltage
I
O
= 500mA
R
DS(ON)
V
OL
Vz
Output On Resistance
RD Output Vds
Output Zener-Breakdown Voltage
I
O
= 300mA
I
O
= 10mA
-
-
-
-
35
625
1.25
0.5
42
900
1.67
-
60
V
V
Conditions
Operating
V
OUT
= 24V
-
-
I
O
= 300mA
V
OUT(SAT)
Min
-
-
0.4
2.4
-
Typ.
2.0
< 0.1
0.5
3
375
Max
4.0
10
0.6
3.6
500
mV
Unit
mA
μA
Sec
Sec
OBSOLETE – PART DISCONTINUED
I
OFF
t
RLP-ON
t
RLP-OFF
Truth Table
(Note 6)
IN-
H
L
-
Note:
IN+
L
H
-
CT
L
L
H
OUT1
H
L
Off
OUT2
L
H
Off
RD
L
L
H
Mode
Rotating
Rotating
Lockup protection activated
6.
Latch-type RD output is low during rotor rotation and high when the rotor is locked (not rotating).
Magnetic Characteristics
(T
A
= +25° V
DD
= 12V, unless otherwise specified, Note 7)
C,
(1mT = 10 Gauss)
Symbol
Bop
Brp
Bhy
Note:
Characteristics
Operate Point
Release Point
Hysteresis
Min
10
-60
-
Typ.
30
-30
60
Max
60
-10
-
Unit
Gauss
Gauss
Gauss
7. The magnetic characteristics may vary with supply voltage, operating temperature and after soldering.
AH286
Document number: DS31030 Rev. 13 - 4
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June 2017
© Diodes Incorporated