complementary outputs for motor’s coil driving, auto
locked shutdown and auto restart functions.
Functional block diagram includes that a regulator
with temperature-compensated band-gap, an
on-chip Hall voltage generator, a comparator, a
Schmitt trigger and two current output drivers. The
regulator can provide wide operational voltage
range. The Hall voltage generator is to amplify the
Hall voltage due to Hall effect. A Schmitt trigger is
to provide switching Hysteresis for noise rejection.
To avoid coil burning, rotor-lock detection circuit will
shutdown the output driver if detect rotor-lock status.
A rotation recovery circuit is to restart the motor
after rotor-lock is removed. In addition, the auto
re-start time is flexible by adjusting the capacitance
(C
T
).
Pin Assignments
Front View
( Branded side)
Pin Descriptions
SIP-5L
Symbol P/I/O Pin #
CT
VCC
DO
DOB
GND
I
P
O
O
P
1
2
3
4
5
Description
Timing cap.
Positive power supply
Driver output
Driver inverted output
Ground
1 2 3 4 5
SIP-5L
( Top view )
VCC
DO
DOB
NC
1
2
3
4
8
7
6
5
SOP-8L / SOP-8L EP
CT
NC
NC
GND
SOP-8L/SOP-8L EP
Symbol
VCC
DO
DOB
NC
CT
GND
Pin #
1
2
3
4,6,7
8
5
Description
Positive power supply
Driver output
Driver inverted output
Not connected for SOP8
Timing cap.
Ground
This datasheet contains new product information. Analog Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev. 0.7 Apr 16, 2004
1/7
AH280
Hall-Effect Smart Fan Driver
Block Diagram
Vcc
2
Regulator
3
Hall
sensor
DO
Amp
Control
Logic
4
DOB
Lock Shutdown
Auto restart
circuits
1
5
Gnd
CT
Ordering Information
AH280 X - X X X - X
Wafer Body
Blank or
A~Z : if necessary
to specify
Package
P: SIP-5L
S: SOP-8L
SP: SOP-8L EP
Lead
L : Lead Free
Blank: Normal
Packing
Blank : Tube or Bulk
A : Tape & Reel
Magnetic
Characteristics
A or B
Application Circuit
10µF
D
( Top view )
AH280
Coil1
Coil2
C
1
Power
input
C
T
( DC Brush-less Fan )
Anachip Corp.
www.anachip.com.tw
2/7
Rev. 0.7 Apr 16, 2004
AH280
Hall-Effect Smart Fan Driver
Absolute Maximum Ratings
Characteristics
Operating Supply Voltage
Output Current
Power Dissipation
Operating Temperature
Storage Temperature
DO(DOB) Vceo D.C. Voltage
P
D
(T
A
= 25°C)
Symbol
V
CC
I
O (AVE)
I
O (PEAK)
SIP-5L / SOP-8L
SOP-8L EP
T
OPR
T
STG
Vceo
Rating
20
500
800
550
1000
-20~85
-55~150
40
Unit
V
mA
mW
°C
°C
Vdc
Electrical Characteristics
Characteristics
Internal Zener-protected Voltage
Quiescent current
(T
A
=25°C, V
CC
=12V, C
T
=1µF)
Symbol
V
Z
I
Q
Output saturation voltage
Charge current
Discharge current
Limiting voltage
On time
Duty ratio
DO
DOB
I
CHG
I
DHG
V
CL
V
CP
T
ON
D
R
Automatic
self-rotation
recovery
circuit
Test Conditions
-
V
CC
=5V
Output1 “ON”
V
CC
=12V
Output1 “ON”
I
O
=0.2A, T
J
=25°C
I
O
=0.4A, T
J
=25°C
I
O
=0.5A, T
J
=25°C
-
-
Clamp Voltage
Comparator Voltage
C
T
=.47µF
T
OFF
/ T
ON
Min, Typ.
-
46
10
10
-
-
-
-
-
-
-
-
3
15
17
0.4
0.6
0.7
2.4
0.5
2.0
1.0
250
5
Max.
-
20
Unit
V
mA
20
-
-
-
-
-
-
-
-
7
V
µA
µA
V
ms
-
Magnetic Characteristics
(1mT = 10 Gauss)
A grade
Characteristics
Operate Point
Release Point
Hysteresis
B grade
Characteristics
Operate Point
Release Point
Hysteresis
Symbol
B
OP
B
RP
B
HYS
Symbol
B
OP
B
RP
B
HYS
T
A
= -20°C to
Min.
Typ.
10
-
-60
-
-
100
T
A
= -20°C to
Min.
Typ.
10
-
-80
-
-
100
+85°C
Max.
60
-10
-
+85°C
Max.
80
-10
-
Unit
G
G
G
Unit
G
G
G
Anachip Corp.
www.anachip.com.tw
3/7
Rev. 0.7 Apr 16, 2004
AH280
Hall-Effect Smart Fan Driver
Rotation detection
The automatic restart circuit detects a motor lock
condition and automatically turns off the output
current. When the lock condition is cleared, the IC
automatically restarts and allows the motor to run.
In the AH280, automatic restart is performed in the
following manner.
A motor lock condition is
detected when the Hall signal stops switching.
The output is ON when CT pin is being charged,
and OFF when CT pin is being discharged.
Hall input
ON
Motor output
OFF
CT
clamp
voltage
CT
comparator
voltage
Motor locked
Motor locked detected
T
on*
T
off*
CT
Motor locked
cleared
Reverts to normal operation
Output ON time (T
on
) and OFF time (T
off
)
Determined by the CT pin capacitor
Where
C
×
(VCL
−
V )
CP
(sec)
T
on
=
I
CHG
C
×
(VCL
−
VCP )
(sec)
T
off
=
I
DHG
C is the capacitance of the CT pin external capacitor
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