Preliminary Datasheet
TWO PHASE HALL EFFECT LATCH WITH LOCKED PROTECTION
AH287
General Description
The AH287 is an integrated Hall sensor with output
drivers for brushless DC motor application. This IC
consists of two complementary outputs for motor’s
coil driving and has automatic lock protection and
auto- restart function relatively. To avoid coil burning,
rotor lock shutdown protection circuit shut down the
output driver if the rotor blocked and then the
automatic recovery circuit will try to restart the motor.
This function repeats while rotor is blocked. Until the
blocking is removed, the motor recovers running
normally. In addition, the auto-restart time is flexible
by adjusting the capacitance (C
CT
).
Placing the device in a variable magnetic field, if the
magnetic flux density is larger than threshold B
OP
, the
DO is turned to sink and DOB is turned to drive. This
output state is held until a magnetic flux density
reversal falls below B
RP
, causing DO to be turned to
drive and DOB turned to sink.
This IC is available in TO-94 package.
Features
On-chip Hall Sensor
•
•
Operating Voltage: 4V to 18V
•
Maximum Output Current: 350mA (ave)
•
Rotor-locked Protection
•
Automatic Restart
•
Adjustable Auto-restart Time
•
Internal Band-gap Regulator for Temperature
Compensation
•
Operating Temperature: -20˚C to 85˚C
•
Low Profile TO-94 Package
•
ESD Rating: 300V (Machine Model)
Application
•
Dual-coil Brushless DC Fan
TO-94
Figure 1. Package Type of AH287
May 2008
Rev. 1. 0
1
BCD Semiconductor Manufacturing Limited
Preliminary Datasheet
TWO PHASE HALL EFFECT LATCH WITH LOCKED PROTECTION
AH287
Functional Block Diagram
Regulator
Temperature
Compensation
2
DO
Hall
Sensor
Amplifier
Schmitt
Trigger
Output
Driver
3
DOB
Lock
Protection and
Auto Restart
1
CT
4
GND
Figure 3. Functional Block Diagram of AH287
Ordering Information
AH287
-
Circuit Type
Package
Z4: TO-94
E1: Lead Free
G1: Green
Magnetic Characteristics
A: 10 to 50 Gauss
B: 5 to 70 Gauss
C: 100 Gauss
Part Number
Marking ID
Lead Free
AH287Z4-E1
AH287Z4-E1
AH287Z4-E1
Package
Temperature
Range
Lead Free
AH287Z4-AE1
AH287Z4-BE1
AH287Z4-CE1
Green
AH287Z4-AG1
AH287Z4-BG1
AH287Z4-CG1
Green
AH287Z4-G1
AH287Z4-G1
AH287Z4-G1
Packing
Type
Bulk
Bulk
Bulk
TO-94
-20 to 85°C
BCD Semiconductor's Pb-free products, as designated with "E1" suffix in the part number, are RoHS compliant.
Products with "G1" suffix are available in green package.
May 2008
Rev. 1. 0
3
BCD Semiconductor Manufacturing Limited
Preliminary Datasheet
TWO PHASE HALL EFFECT LATCH WITH LOCKED PROTECTION
AH287
Absolute Maximum Ratings (Note 1, T
A
=25°C)
Parameter
Supply Voltage
Magnetic Flux Density
Continuous
Output Current
Hold
Peak (Start Up)
Power Dissipation
Thermal
Resistance
Die to Atmosphere
Die to Package Case
P
D
θ
JA
θ
JC
T
STG
I
OUT
Symbol
V
CC
B
Value
20
Unlimited
350
550
750
550
227
49
-50 to 150
300
3000
Unit
V
Gauss
mA
mA
mA
mW
°C/W
°C/W
°C
V
V
Storage Temperature
ESD (Machine Model)
ESD (Human Body Model)
Note 1: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to
the device. These are stress ratings only, and functional operation of the device at these or any other conditions
beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute
Maximum Ratings” for extended periods may affect device reliability.
Recommended Operating Conditions
Parameter
Supply Voltage
Ambient Temperature
Symbol
V
CC
T
A
Min
4
-20
Max
18
85
Unit
V
°C
May 2008
Rev. 1. 0
4
BCD Semiconductor Manufacturing Limited
Microcontroller MCU
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