AH292
LOW VOLTAGE HALL-EFFECT SMART FAN MOTOR
CONTROLLER
Description
AH292 is a monolithic fan motor controller with Hall sensor’s
capability. It contains two complementary open-collector
transistors for motor’s coil driving, automatic lock current
shutdown, and recovery protections. In addition a Frequency
generator (FG) output is also available for speed detection.
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.
The AH292 is available in SOT89-5L package.
Pin Assignments
(Top View)
Vdd
1
2
292
5
FG
GND
DO
3
7
DOB
4
SOT89-5L
Features
•
•
•
•
•
•
•
•
•
On Chip Hall Sensor
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
O(AVE)
= 400mA
Packaged in SOT89-5L
Green Molding Compound
Applications
•
•
Two-coil BLDC cooling fans
Low to medium voltage, low power BLDC motors
Typical Application Circuit
(Note 1)
D2
Vdd
(1.8V/5.75V)
R
pu
D1
1
2
3
4
5
292
Coil 2
GND
Coil 1
FG
C3
Notes:
R1
C1
R2
C2
1. R1, R2: typical 56 Ohm
C1, C2, C3: typical 2.2µF
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
AH292
Document number: DS31049 Rev. 7 - 2
1 of 8
www.diodes.com
June 2010
© Diodes Incorporated
AH292
LOW VOLTAGE HALL-EFFECT SMART FAN MOTOR
CONTROLLER
Absolute Maximum Ratings
(T
A
= 25°C)
Symbol
Vdd
I
O(AVE)
I
O(PEAK)
P
D
T
ST
T
J
Characteristics
Operating Supply Voltage
Output Current
Output Current
Power Dissipation
Storage Temperature
Maximum Junction Temperature
Rating
8
400
700
800
-55 ~ 150
150
Unit
V
mA
mA
mW
°C
°C
Recommended Operating Conditions
Symbol
Vdd
T
A
Notes:
Characteristic
Supply Voltage (Note 2)
Operating Ambient Temperature
Conditions
Operating
Operating
Min
1.8
-20
Max
5.75
100
Unit
V
°C
2. The output of IC will be switched after the supply voltage is over 1.8V, but the magnetic characteristics won't be normal until the
supply is over 2.0V.
Electrical Characteristics
(T
A
= 25
°C,
Vdd = 5V, unless otherwise specified)
Symbol
Idd
T
RLP-ON
T
RLP-OFF
V
OUT(SAT)
R
DS(ON)
V
OL
Vz
Truth Table
IN-
H
L
-
Characteristics
Supply current
Rotor Lock Protection On Time
Rotor Lock Protection Off Time
Output Saturation Voltage
Output On Resistance
FG Output Vds
Output Zener-Breakdown Voltage
Conditions
Operating
Min
-
-
2.4
-
-
-
-
-
Typ.
2.6
0.4
3
300
600
1.75
0.5
15
Max
4.0
-
3.6
-
-
-
-
-
Unit
mA
Sec
Sec
mV
mV
ohm
V
V
I
O
= 180mA
I
O
= 350mA
I
O
= 10mA
IN+
L
H
-
CT
L
L
H
OUT1
H
L
off
OUT2
L
H
off
FG
H
L
-
Mode
Rotating
Rotating
Lockup protection activated
AH292
Document number: DS31049 Rev. 7 - 2
3 of 8
www.diodes.com
June 2010
© Diodes Incorporated
AH292
LOW VOLTAGE HALL-EFFECT SMART FAN MOTOR
CONTROLLER
Magnetic Characteristics
(T
A
= 25
°C,
Vdd = 5V, unless otherwise specified, Note 3)
(1mT = 10 Gauss)
Symbol
Bop
Brp
Bhy
Notes:
Characteristics
Operation Point
Release Point
Hysteresis
Min
10
-60
-
Typ.
30
-30
60
Max
60
-10
-
Unit
Gauss
Gauss
Gauss
3. The magnetic characteristics may vary with supply voltage, operating temperature and after soldering.
Operating Characteristics
DOB
Output Voltage in Volts
Output Voltage in Volts
DO
RP
12
10
8
6
4
OFF
OFF
12
10
8
6
4
OP
ON
2
OP
Vsat
RP
Vsat
2
ON
Brp
0
Bop
Magnetic Flux Density in Gauss
Brp
0
Bop
Magnetic Flux Density in Gauss
S
Marking
side
N
( SOT89-5L )
AH292
Document number: DS31049 Rev. 7 - 2
4 of 8
www.diodes.com
June 2010
© Diodes Incorporated