A3282
Chopper-Stabilized Hall-Effect Latch
Discontinued Product
This device is no longer in production. The device should not be
purchased for new design applications. Samples are no longer
available.
Date of status change: July 30, 2010
Recommended Substitutions:
Our next generation recommended substitutes are:
• For the A3282ELHLT-T, we recommend the A1222ELHLX-T.
• For the A3282LLHLT-T, we recommend the A1222LLHLX-T.
• For the A3282LUA-T, we recommend the A1222LUA-T.
NOTE: For detailed information on purchasing options, contact your
local Allegro field applications engineer or sales representative.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, revisions to the anticipated product life cycle plan
for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The
information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no respon-
sibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use.
A3282
Chopper-Stabilized Hall-Effect Latch
Features and Benefits
▪
Chopper stabilization
▫
Superior temperature stability
▫
Extremely low switchpoint drift
▫
Insensitive to physical stress
▪
Reverse battery protection
▪
Output short circuit protection
▪
Solid state reliability
▪
Small size
▪
Robust EMC capability
▪
High ESD ratings (HBM)
Description
The A3282 Hall-effect sensor IC is a temperature stable,
stress-resistant latch. Superior high-temperature performance
is made possible through an Allegro
®
dynamic offset
cancellation that utilizes chopper-stabilization. This
method reduces the offset voltage normally caused by device
overmolding, temperature dependencies, and thermal stress.
The A3282 complements the current Allegro family of chopper-
stabilized latching devices.
The A3282 includes the following on a single silicon chip:
voltage regulator, Hall-voltage generator, small-signal
amplifier, chopper stabilization, Schmitt trigger, and a short
circuit protected open-drain output. Advanced BiCMOS wafer
fabrication processing is used to take advantage of low-voltage
requirements, component matching, very low input-offset
errors, and small component geometries.
This device requires the presence of both south and north
polarity magnetic fields for operation. In the presence of a
south polarity field of sufficient strength, the device output
latches on, and only switches off when a north polarity field
of sufficient strength is present.
Packages: 3 pin SOT23W (suffix LH), and
3 pin SIP (suffix UA)
Continued on the next page…
Not to scale
Functional Block Diagram
VCC
Regulator
To All Subcircuits
Sample and Hold
Dynamic Offset
Cancellation
Low-Pass
Filter
VOUT
Amp
Control
Current Limit
<1Ω
GND
A3282-DS, Rev. 8
A3282
Chopper-Stabilized Hall Effect Latch
LH is an SOT23-W, a miniature low-profile surface-mount package,
while package UA is a three-lead ultramini SIP for through-hole
mounting. Each package is available in a lead (Pb) free version,
with 100% matte tin plated leadframes.
Description (continued)
The A3282 is rated for operation between the ambient temperatures
–40°C and 85°C for the E temperature range, and –40°C to 150°C for
the L temperature range. The two package styles available provide
magnetically optimized solutions for most applications. Package
Selection Guide
Part Number
Packing
1
Mounting
3-pin SOT23W surface mount
3-pin SOT23W surface mount
3-pin SIP through hole
Ambient, T
A
(°C)
–40 to 85
–40 to 150
–150
150
B
RP(MIN)
(G)
B
OP(MAX)
(G)
A3282ELHLT-T
2
7-in. reel, 3000 pieces/reel
A3282LLHLT-T
2
7-in. reel, 3000 pieces/reel
A3282LUA-T
2
Bulk, 500 pieces/bag
1
Contact Allegro
2
Variant
for additional packing options.
is in production but has been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of the variant
is currently restricted to existing customer applications. The variant should not be purchased for new design applications because
obsolescence in the near future is probable. Samples are no longer available. Status change: August 12, 2009.
Absolute Maximum Ratings
Characteristic
Supply Voltage
Reverse-Supply Voltage
Output Off Voltage
Output Current
Reverse-Output Current
Magnetic Flux Density
Operating Ambient Temperature
Maximum Junction Temperature
Storage Temperature
Symbol
V
CC
V
RCC
V
OUT
I
OUTSINK
I
ROUT
B
T
A
T
J
(max)
T
stg
Range E
Range L
Notes
Rating
28
–18
28
Internally Limited
–10
Unlimited
–40 to 85
–40 to 150
165
–65 to 170
Units
V
V
V
–
mA
G
ºC
ºC
ºC
ºC
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
2
A3282
Chopper-Stabilized Hall Effect Latch
OPERATING CHARACTERISTICS
valid over full operating voltage and ambient temperature ranges, unless otherwise noted
Characteristic
Electrical Characteristics
Supply Voltage
1
Output Leakage Current
Output On Voltage
Output Current Limit
Power-On Time
Chopping Frequency
Output Rise Time
2
Output Fall Time
2
Supply Current
Reverse Battery Current
Supply Zener Clamp Voltage
Supply Zener Current
3
Magnetic Characteristics
4
Operate Point
Release Point
Hysteresis
1
2
Symbol
V
CC
I
OUTOFF
V
OUT(SAT)
I
OM
t
PO
f
c
t
r
t
f
I
CCON
I
CCOFF
I
RCC
V
Z
I
Z
B
OP
B
RP
B
HYS
Test Conditions
Operating, T
J
< 165°C
V
OUT
= 24 V, B < B
RP
I
OUT
= 20 mA, B > B
OP
B > B
OP
V
CC
> 3.6 V
R
LOAD
= 820
Ω,
C
S
= 20 pF
R
LOAD
= 820
Ω,
C
S
= 20 pF
B > B
OP
B < B
RP
V
RCC
= –18 V
I
CC
= 6.5 mA; T
A
= 25°C
V
S
= 28 V
South pole adjacent to branded face of device
North pole adjacent to branded face of device
B
OP
– B
RP
Min.
3.6
–
–
30
–
–
–
–
–
–
–
28
–
70
–150
140
Typ.
–
–
250
–
8
200
0.2
0.2
1.6
1.6
–
–
–
110
–110
220
Max.
24
10
500
60
50
–
1
1
3.5
3.5
–2
–
6.5
150
–70
300
Units
V
μA
mV
mA
μs
kHz
μs
μs
mA
mA
mA
V
mA
G
G
G
Maximum voltage must be adjusted for power dissipation and junction temperature, see
Power Derating
section.
C
S
= oscilloscope probe capacitance.
3
Maximum current limit is equal to the maximum I
CC(MAX)
+ 3 mA.
4
Magnetic
fl
ux density, B, is indicated as a negative value for north-polarity magnetic
fi
elds, and as a positive value for south-polarity magnetic
fi
elds.
This so-called algebraic convention supports arithmetic comparison of north and south polarity values, where the relative strength of the
fi
eld is indicated
by the absolute value of B, and the sign indicates the polarity of the
fi
eld (for example, a –100 G
fi
eld and a 100 G
fi
eld have equivalent strength, but
opposite polarity).
DEVICE QUALIFICATION PROGRAM
Contact Allegro for information.
EMC (Electromagnetic Compatibility) REQUIREMENTS
Contact Allegro for information.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
3
A3282
Chopper-Stabilized Hall Effect Latch
Electrical Characteristic Data
Supply Current (On) versus Ambient Temperature
5.0
4.0
5.0
4.0
Supply Current (On) versus Supply Voltage
I
CCON
(mA)
3.0
2.0
1.0
0
–50
0
50
T
A
(°C)
100
150
I
CCON
(mA)
V
CC
(V)
24
3.6
T
A
(°C)
–40
25
150
3.0
2.0
1.0
0
0
5
10
V
CC
(V)
15
20
25
Supply Current (Off) versus Ambient Temperature
Supply Current (Off) versus Supply Voltage
5.0
4.0
5.0
4.0
I
CCOFF
(mA)
I
CCOFF
(mA)
V
CC
(V)
3.0
2.0
1.0
0
–50
0
50
T
A
(°C)
100
150
24
3.6
T
A
(°C)
–40
25
150
3.0
2.0
1.0
0
0
5
10
V
CC
(V)
15
20
25
Output Voltage (On) versus Ambient Temperature
500
450
400
350
500
450
400
350
Output Voltage (On) versus Supply Voltage
V
OUT(SAT)
(mV)
V
OUT(SAT)
(mV)
300
250
200
150
100
50
0
–50
0
50
T
A
(°C)
100
150
V
CC
(V)
24
3.6
300
250
200
150
100
50
0
0
5
10
V
CC
(V)
15
20
25
T
A
(°C)
–40
25
150
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
4