Data Sheet
SINGLE PHASE HALL EFFECT LATCH
General Description
The AH477 is an integrated Hall sensor with H-
bridged output driver designed for brushless DC motor
applications. The device includes an on-chip Hall sen-
sor for magnetic sensing, an amplifier that amplifies
the Hall voltage, a comparator to provide switching
hysteresis for noise rejection, a bi-directional drivers
for sinking and driving large current load. It also
includes an internal bandgap regulator to provide tem-
perature compensated bias for internal circuits and
allows a wide operating supply voltage range.
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 the magnetic flux density
reverses and falls below B
RP,
then causes DO to be
turned to drive and DOB turned to sink.
AH477 is available in TO-94 (SIP-4L) package.
AH477
Features
·
·
·
·
·
·
·
·
On-Chip Hall Sensor
Operating Voltage: 3.5V to 18V
H-Bridge Output Drivers for Single Coil
Internal Bandgap Regulator for Temperature
Compensation
Low Output Switching Current Noise
-20
o
C to 85
o
C Operating Temperature
Low Profile TO-94 (SIP-4L) Package
ESD Rating: 3000V (Human Body Model)
Applications
·
·
Single-Coil Brushless DC Motor
Single-Coil Brushless DC Fan
TO-94
Figure 1. Package Type of AH477
Oct. 2009 Rev. 1. 3
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BCD Semiconductor Manufacturing Limited
Data Sheet
SINGLE PHASE HALL EFFECT LATCH
Functional Block Diagram
V
CC
1
Regulator
2
DO
V
CC
AH477
Hall
Sensor
Amplifier
Schmitt
Trigger
Pre-
Driver
V
CC
3
4
GND
DOB
Figure 3. Functional Block Diagram of AH477
Ordering Information
AH477
Circuit Type
Package
Z4: TO-94 (SIP-4L)
Part Number
Lead Free
AH477Z4-AE1
AH477Z4-BE1
Green
AH477Z4-AG1
AH477Z4-BG1
-
E1: Lead Free
G1: Green
Magnetic Characteristics
A: 5 to 70 Gauss
B: 100 Gauss
Marking ID
Lead Free
AH477Z4-E1
AH477Z4-E1
Green
AH477Z4-G1
AH477Z4-G1
Packing
Type
Bulk
Bulk
Package
TO-94
Temperature
Range
-20 to 85
o
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.
Oct. 2009 Rev. 1. 3
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BCD Semiconductor Manufacturing Limited
Data Sheet
SINGLE PHASE HALL EFFECT LATCH
(T
A
=25
o
C)
AH477
Absolute Maximum Ratings (Note 1)
Parameter
Supply Voltage
Magnetic Flux Density
Continuous
Output Current
Hold
Peak (start up)
Power Dissipation
Die to atmosphere
Thermal Resistance
Die to package case
Storage Temperature
ESD (Machine Model)
ESD (Human Body Model)
P
D
θJA
θJC
T
STG
I
O
Symbol
V
CC
B
Value
20
Unlimited
250
300
600
550
227
49
-50 to 150
300
3000
Unit
V
Gauss
mA
mA
mA
mW
o
C/W
o
C/W
o
C
V
V
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. "Absolute Maximum Ratings" for extended period may affect
device reliability.
Recommended Operating Conditions
(T
A
=25
o
C)
Parameter
Supply Voltage
Ambient Temperature
Symbol
V
CC
T
A
Min
3.5
-20
Max
18
85
Unit
V
o
C
Oct. 2009 Rev. 1. 3
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BCD Semiconductor Manufacturing Limited
Data Sheet
SINGLE PHASE HALL EFFECT LATCH
Electrical Characteristics
(T
A
=25
o
C, V
CC
=14V, unless otherwise specified)
Parameter
Output Saturation Voltage (Sink)
Output Saturation Voltage (Drive)
Supply Current
Output Rise Time
Output Fall Time
Switch Time Differential
V
SAT
I
CC
tr
tf
∆t
Symbol
Test Condition
V
CC
=14V, I
O
=200mA
V
CC
=14V, I
O
=200mA
V
CC
=20V, Output Open
R
L
=820Ω, C
L
=20pF
R
L
=820Ω, C
L
=20pF
R
L
=820Ω, C
L
=20pF
V
CC
-
1.5
Min
Typ
0.25
V
CC
-
1.0
14
3.0
0.3
3.0
Max
0.8
V
CC
25
10
1.5
10
Unit
V
V
mA
µs
µs
µs
AH477
Magnetic Characteristics
(T
A
=25
o
C)
Parameter
Operating Point
Releasing Point
Hysteresis
Symbol
B
OP
B
RP
B
HYS
Grade
A
B
A
B
-70
-100
70
Min
5
Typ
Max
70
100
-5
Unit
Gauss
Gauss
Gauss
Gauss
Gauss
Test Circuit
AH477
S
Marking Side
V
CC
V
CC
DO DOB GND
1
2
3
4
C1
0.1µF
820Ω
N
Oct. 2009 Rev. 1. 3
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BCD Semiconductor Manufacturing Limited