ALLEGRO A3281LU

Data Sheet
27609.20b
3280, 3281,
AND 3283
CHOPPER-STABILIZED, PRECISION
HALL-EFFECT LATCHES
Suffix '–LT' & '–UA' Pinning
X
(SOT89/TO-243AA & ultra-mini SIP)
PTCT
CC
2
3
OUTPUT
SUPPLY
1
GROUND
V
Dwg. PH-003-2
Pinning is shown viewed from branded side.
ABSOLUTE MAXIMUM RATINGS
at TA = +25°C
Supply Voltage, VCC ........................ 26.5 V
Reverse Battery Voltage, VRCC .......... -30 V
Magnetic Flux Density, B ........... Unlimited
Output Off Voltage, VOUT ................... 26 V
Continuous Output Current,
IOUT .......................................... 25 mA*
Reverse Output Current, IOUT ........ -50 mA
Package Power Dissipation, PD . See Graph
Junction Temperature, TJ ............... +165°C
Operating Temperature Range, TA
Suffix ‘E–’ .................. -40°C to +85°C
Suffix ‘L–’ ................ -40°C to +150°C
Storage Temperature Range,
TS .............................. -65°C to +170°C
*Internal current limiting is intended to protect
the device from output short circuits.
The A3280--, A3281--, and A3283-- Hall-effect latches are extremely temperature-stable and stress-resistant sensors especially suited
for operation over extended temperature ranges to +150°C. Superior
high-temperature performance is made possible through dynamic offset
cancellation, which reduces the residual offset voltage normally caused
by device overmolding, temperature dependencies, and thermal stress.
The three devices are identical except for magnetic switch points.
Each device includes on a single silicon chip a voltage regulator,
Hall-voltage generator, small-signal amplifier, chopper stabilization,
Schmitt trigger, and a short-circuit protected open-collector output to
sink up to 25 mA. A south pole of sufficient strength will turn the
output on. A north pole is necessary to turn the output off. An on-board
regulator permits operation with supply voltages of 4.2 to 24 volts.
The first character of the part number suffix determines the device
operating temperature range; suffix ‘E–’ is for -40°C to +85°C and
‘L–’ is -40°C to +150°C. Three package styles provide a magnetically
optimized package for most applications. Suffix ‘–LH’ is a miniature
SOT23W low-profile surface-mount package, ‘–LT’ is a miniature
SOT89/TO-243AA transistor package for surface-mount applications;
while suffix ‘–UA’ is a three-lead ultra-mini-SIP for through-hole
mounting.
FEATURES
■
■
■
■
■
■
■
■
Symmetrical Switch Points
Resistant to Physical Stress
Superior Temperature Stability
Output Short-Circuit Protection
Operation From Unregulated Supply
Reverse Battery Protection
Solid-State Reliability
Small Size
Always order by complete part number: the prefix ‘A’ + the basic fourdigit part number + a suffix to indicate operating temperature range +
a suffix to indicate package style, e.g., A3281ELH .
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
FUNCTIONAL BLOCK DIAGRAM
SUPPLY
TO ALL
SUBCIRCUITS
LOW-PASS
FILTER
OUTPUT
SAMPLE
& HOLD
X
DYNAMIC
OFFSET CANCELLATION
REG.
CONTROL
CURRENT
LIMIT
<1Ω
GROUND
Dwg. FH-020-1
Suffix ‘–LH’ Pinning
(SOT23W)
3
700
Suffix "–UA"
RθJA = 165°C/W
X
600
500
PTCT
Suffix "–LT"
RθJA = 180°C/W
Suffix "–LH"
RθJA = 228°C/W
400
V
300
CC
1
20
40
60
100
80
120
AMBIENT TEMPERATURE in °C
140
160
180
Dwg. GH-046-2D
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 2000, 2003, 2004 Allegro MicroSystems, Inc.
OUTPUT
Suffix "L–"
GROUND
Suffix "E–"
100
0
2
2
200
SUPPLY
ALLOWABLE PACKAGE POWER DISSIPATION in MILLIWATTS
800
Dwg. PH-003-4
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
ELECTRICAL CHARACTERISTICS over operating temperature range.
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
4.2
–
24
V
Supply Voltage Range
VCC
Operating, TJ < 165°C1
Output Leakage Current
IOFF
VOUT = 24 V, B < BRP
–
–
10
µA
VOUT(SAT)
IOUT = 20 mA, B > BOP
–
185
500
mV
Output Saturation Voltage
Output Current Limit
IOM
B > BOP
30
–
60
mA
Power-On Time
tpo
VCC > 4.2 V
–
–
50
µs
Chopping Frequency
fC
–
340
–
kHz
Output Rise Time
tr
RL = 820 Ω, CL = 20 pF
–
0.2
2.0
µs
Output Fall Time
tf
RL = 820 Ω, CL = 20 pF
–
0.1
2.0
µs
B < BRP, VCC = 12 V
–
3.0
8.0
mA
B > BOP, VCC = 12 V
–
4.0
8.0
mA
VRCC = -30 V
–
–
-5.0
mA
Supply Current
ICC
Reverse Battery Current
ICC
Zener Voltage
VZ + VD
ICC = 15 mA, TA = 25°C
28
32
37
V
Zener Impedance
zz + z D
ICC = 15 mA, TA = 25°C
–
50
–
Ω
NOTES:1. Maximum voltage must be adjusted for power dissipation and junction temperature.
2. BOP = operate point (output turns on); BRP = release point (output turns off).
3. Typical Data is at TA = +25°C and VCC = 12 V and is for design information only.
MAGNETIC CHARACTERISTICS over operating voltage range.
Part Numbers1
A3280
Characteristic
Test Conditions
Operate Point, BOP
at TA = +25°C and TA = max.
5.0
22
40
15
50
at TA = -40°C
5.0
–
40
15
at TA = +25°C and TA = max.
-40
-23
-5.0
at TA = -40°C
-40
–
at TA = +25°C and TA = max.
10
at TA = -40°C
–
Release Point, BRP
Hysteresis, Bhys
(BOP - BRP)
Min.
A3281
Typ. Max.
Min.
A3283
Typ. Max.
Min.
Typ. Max.
Units
90
100
150
180
G
–
90
100
–
200
G
-90
-50
-15
-180
-150
-100
G
-5.0
-90
–
-15
-200
–
-100
G
45
80
30
100
180
–
300
360
G
–
80
–
–
180
–
–
360
G
NOTES:1. Complete part number includes a suffix to identify operating temperature range (E or L) and
package type (LH, LT, or UA).
2. As used here, negative flux densities are defined as less than zero (algebraic convention) and -50 G is less than +10 G.
3. Typical Data is at TA = +25°C and VCC = 12 V and is for design information only.
4. 1 gauss (G) is exactly equal to 0.1 millitesla (mT).
www.allegromicro.com
3
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
TYPICAL OPERATING CHARACTERISTICS
as a function of temperature
A3281* SWITCH POINTS
A3280* SWITCH POINTS
50
100
40
80
60
OPERATE POINT
SWITCH POINTS IN GAUSS
SWITCH POINTS IN GAUSS
30
20
10
0
VCC = 4.5 V
VCC = 24 V
-10
RELEASE POINT
-20
20
0
-40
-60
-40
-80
-25
0
25
50
75
100
AMBIENT TEMPERATURE IN °C
125
150
Dwg. GH-026-3
VCC = 4.5 V to 24 V
-20
-30
-50
-50
OPERATE POINT
40
-100
-50
RELEASE POINT
-25
0
25
50
75
100
125
AMBIENT TEMPERATURE IN ° C
A3283* SWITCH POINTS
200
160
OPERATE POINT
SWITCH POINTS IN GAUSS
120
80
40
0
VCC = 4.5 V
VCC = 24 V
-40
-80
-120
RELEASE POINT
-160
-200
-50
-25
0
25
50
75
100
AMBIENT TEMPERATURE IN ° C
125
150
Dwg. GH-026-6
* Complete part number includes a suffix denoting operating temperature range (E or L) and package type (LH, LT, or UA).
4
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
150
Dwg. GH-026-4
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
TYPICAL OPERATING CHARACTERISTICS
as a function of temperature (cont'd)
OUTPUT SATURATION VOLTAGE
SUPPLY CURRENT
6.0
300
IOUT = 20 mA
VCC = 12 V
5.0
SUPPLY CURRENT IN mA
SATURATION VOLTAGE IN mV
VCC = 12 V
200
100
4.0
OUTPUT ON, B > BOP
3.0
OUTPUT OFF, B < BRP
0
-50
-25
0
25
50
75
100
125
2.0
-50
150
-25
0
25
50
75
100
125
150
AMBIENT TEMPERATURE IN °C
AMBIENT TEMPERATURE IN ° C
Dwg. GH-028-5
Dwg. GH-029-4
TYPICAL OPERATING CHARACTERISTICS
as a function of supply voltage
A3281* SWITCH POINTS
A3280* SWITCH POINTS
80
40
OPERATE POINT
OPERATE POINT
40
TA = 150°C
TA = -40°C
0
-20
-40
3.0
SWITCH POINT IN GAUSS
SWITCH POINT IN GAUSS
20
RELEASE POINT
3.5
4.0
4.5
5.0
24
TA = 150°C
TA = -40°C
0
-40
-80
3.0
RELEASE POINT
3.5
4.0
4.5
5.0
24
SUPPLY VOLTAGE IN VOLTS
SUPPLY VOLTAGE IN VOLTS
Dwg. GH-021-3
Dwg. GH-021-1
* Complete part number includes a suffix denoting operating temperature range (E or L) and package type (LH, LT, or UA).
www.allegromicro.com
5
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
TYPICAL OPERATING CHARACTERISTICS
as a function of supply voltage (cont’d)
SENSOR LOCATIONS
OUTPUT SATURATION VOLTAGE
Package Designator ‘LH’
250
ACTIVE AREA DEPTH
0.011"
0.28 mm
NOM
IOUT = 20 mA
TA = 150°C
TA = +25°C
TA = -40°C
0.059"
1.49 mm
3
SATURATION VOLTAGE IN mV
0.038"
0.96 mm
A
1
2
Dwg. MH-025
Package Designator ‘LT’
ACTIVE AREA DEPTH
0.0305"
0.775 mm
NOM
225
200
175
0.088"
2.24 mm
0.045"
1.14 mm
150
3.0
3.5
4.0
4.5
24
5.0
SUPPLY VOLTAGE IN VOLTS
A
Dwg. GH-055-1
1
2
3
SUPPLY CURRENT
Dwg. MH-008-8A
8.0
Package Designator ‘UA’
ACTIVE AREA DEPTH
0.0195"
0.50 mm
NOM
7.0
6.0
SUPPLY CURRENT IN mA
0.080"
2.04 mm
0.056"
1.44 mm
A
BRANDED
SURFACE
1
2
OUTPUT ON
TA = 150°C
TA = +25°C
TA = -40°C
3
5.0
4.0
3.0
2.0
1.0
Dwg. MH-011-9B
0
3.0
Although sensor location is accurate to three sigma for a
particular design, product improvements may result in small
changes to sensor location.
6
4.0
5.0
6.0
7.0
8.0
9.0
SUPPLY VOLTAGE IN VOLTS
Allegro
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
10
11
12
Dwg. GH-058-4
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
FUNCTIONAL DESCRIPTION
SAMPLE
& HOLD
REG
X
Dwg. EH-012
B
+V
—
HALL
VOLTAGE
+
Dwg. AH-011-2
+V
VCC
OUTPUT VOLTAGE
Chopper-Stabilized Technique. The Hall element can be
considered as a resistor array similar to a Wheatstone bridge. A
large portion of the offset is a result of the mismatching of these
resistors. These devices use a proprietary dynamic offset
cancellation technique, with an internal high-frequency clock to
reduce the residual offset voltage of the Hall element that is
normally caused by device overmolding, temperature dependencies, and thermal stress. The chopper-stabilizing technique
cancels the mismatching of the resistor circuit by changing the
direction of the current flowing through the Hall plate using
CMOS switches and Hall voltage measurement taps, while
maintaing the Hall-voltage signal that is induced by the external
magnetic flux. The signal is then captured by a sample-andhold circuit and further processed using low-offset bipolar
circuitry. This technique produces devices that have an
extremely stable quiescent Hall output voltage, are immune to
thermal stress, and have precise recoverability after temperature
cycling. This technique will also slightly degrade the device
output repeatability. A relatively high sampling frequency is
used in order that faster signals can be processed.
More detailed descriptions of the circuit operation can be
found in: Technical Paper STP 97-10, Monolithic Magnetic
Hall Sensor Using Dynamic Quadrature Offset Cancellation
and Technical Paper STP 99-1, Chopper-Stabilized Amplifiers
With A Track-and-Hold Signal Demodulator.
Operation. The output of these devices switches low (turns
on) when a magnetic field perpendicular to the Hall sensor
exceeds the operate point threshold (BOP). After turn-on, the
output is capable of sinking 25 mA and the output voltage is
VOUT(SAT). Note that the device latches; that is, a south pole of
sufficient strength towards the branded surface of the device
will turn the device on; removal of the south pole will leave the
device on. When the magnetic field is reduced below the
release point (BRP), the device output goes high (turns off). The
difference in the magnetic operate and release points is the
hysteresis (Bhys) of the device. This built-in hysteresis allows
clean switching of the output even in the presence of external
mechanical vibration and electrical noise.
Powering up in the absence of a magnetic field (less than
BOP and higher than BRP) will allow an indeterminate output
state. The correct state is warranted after the first excursion
beyond BOP or BRP.
B RP
B OP
VOUT(SAT)
0
-B
0
FLUX DENSITY
www.allegromicro.com
+B
Dwg. GH-034-5
7
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
APPLICATIONS INFORMATION
It is strongly recommended that an external bypass capacitor be connected (in close proximity to the Hall sensor) between the
supply and ground of the device to reduce both external noise and noise generated by the chopper-stabilization technique.
3
SUPPLY
2
PTCT
OUTPUT
1
SUPPLY
V
CC
0.1 µF
X
Dwg. EH-013
The simplest form of magnet that will operate these devices is a ring magnet. Other methods of operation, such as linear
magnets, are possible.
Extensive applications information for Hall-effect sensors is available in:
• Hall-Effect IC Applications Guide, Application Note 27701;
• Hall-Effect Devices: Soldering, Gluing, Potting, Encapsulating, and Lead Forming, Application Note 27703.1;
• Soldering of Through-Hole Hall-Sensor Dervices, Application Note 27703; and
• Soldering of Surface-Mount Hall-Sensor Devices, Application Note 27703.2.
More detailed descriptions of the chopper-stabilized circuit operation can be found in:
• Monolithic Magnetic Hall Sensor Using Dynamic Quadrature Offset Cancelation, Technical Paper STP 97-10; and
• Chopper-Stabilized Amplifiers With A Track-and-Hold Signal Demodulator, Technical Paper STP 99-1.
All are provided at
www.allegromicro.com
The products described herein are manufactured under one or
more of the following U.S. patents: 5,045,920; 5,264,783; 5,442,283;
5,389,889; 5,581,179; 5,517,112; 5,619,137; 5,621,319; 5,650,719;
5,686,894; 5,694,038; 5,729,130; 5,917,320; and other patents
pending.
Allegro MicroSystems, Inc. reserves the right to make, from time to
time, such departures from the detail specifications as may be required
to permit improvements in the performance, reliability, or
manufacturability of its products. Before placing an order, the user is
cautioned to verify that the information being relied upon is current.
Allegro products are not authorized for use as critical components
in life-support appliances, devices, or systems without express written
approval.
The information included herein is believed to be accurate and
reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other rights of
third parties that may result from its use.
8
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
PACKAGE DESIGNATOR ‘LH’
(SOT23W, fits SC-59A solder-pad layout)
Dimensions in Inches
(for reference only)
Dimensions in Millimeters
(controlling dimensions)
3.10
2.90
0.122
0.114
0.50
0.30
0.020
0.012
0.083
0.073
3
1
2
0.118
0.106
2.10
1.85
0.010
BSC
3.00
2.70
3
1
2
SEATING PLANE
REF
0° TO 8°
0.037
0.006
0.000
SEATING PLANE
0.55
0.010
REF
0.045
0.032
0° TO 8°
0.95
MIN
BSC
BSC
GAUGE PLANE
GAUGE PLANE
0.022
0.25
MIN
BSC
0.0079
0.0050
0.15
0.00
0.25
0.20
0.127
1.13
0.87
Dwg. MA-010-3D mm
Dwg. MA-010-3D in
0.70
0.028
3
3
0.039
1.00
0.094
1
2
2.40
1
2
0.037
0.95
Dwg. MA-011-3 in
Dwg. MA-011-3 mm
NOTES: 1. Tolerances on package height and width represent allowable mold offsets. Dimensions given are
measured at the widest point (parting line).
2. Exact body and lead configuration at vendor’s option within limits shown.
3. Height does not include mold gate flash.
4. Where no tolerance is specified, dimension is nominal.
5. Add "LT" to part number for tape and reel.
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9
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
PACKAGE DESIGNATOR ‘LT’
(SOT89/TO-243AA)
Dimensions in Inches
(for reference only)
0.181
0.173
0.072
0.064
0.167
0.155
2
1
0.063
0.055
3
Dimensions in Millimeters
(controlling dimensions)
0.0173
0.0138
0.090
0.084
0.102
0.090
4.25
3.94
0.0189
0.0142
0.0221
0.0173
0.047
0.035
0.059
BSC
4.60
4.40
1.83
1.62
2
1
BSC
3.00
BSC
Dwg. MA-009-3A in
B
0.031
A
Dwg. MA-009-3A mm
2.5
2.0
0.098
0.079
B
0.102
0.8
2.6
A
0.181
1
2
2.29
2.13
0.56
0.44
1.50
BSC
2.60
2.29
3
4.6
3 0.047
0.028
0.031
TYP
TYP
1
2
3
1.2
0.7
0.8
TYP
TYP
Pads 1, 2, 3, and A — Standard SOT89 Layout
Pads 1, 2, 3, and B — Low-Stress Version
Pads 1, 2, and 3 only — Lowest Stress, But Not Self Aligning
Pads 1, 2, 3, and A — Standard SOT89 Layout
Pads 1, 2, 3, and B — Low-Stress Version
Pads 1, 2, and 3 only — Lowest Stress, But Not Self Aligning
Dwg. MA-012-3 in
Dwg. MA-012-3 mm
NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.
2. Supplied in bulk pack (500 pieces per bag) or add "TR" to part number for tape and reel.
3. Only low-temperature (≤240°C) reflow-soldering techniques are recommended for SOT89 devices.
10
0.44
0.35
0.48
0.36
1.20
0.89
0.118
1.60
1.40
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3280, 3281, AND 3283
CHOPPER-STABILIZED,
PRECISION
HALL-EFFECT LATCHES
PACKAGE DESIGNATOR ‘UA’
Dimensions in Millimeters
(for reference only)
Dimensions in Inches
(controlling dimensions)
0.164
0.159
4.17
4.04
0.062
0.058
45°
1.57
1.47
45°
3.10
2.97
0.122
0.117
45°
45°
0.085
1
2
3
0.031
2.16
1
2
0.79
3
MAX
MAX
0.640
0.600
16.26
15.24
0.0173
0.0138
0.0189
0.0142
SEE NOTE
0.44
0.35
0.48
0.36
SEE NOTE
1.27
0.050
BSC
BSC
Dwg. MH-014E in
Dwg. MH-014E mm
Radial Lead Form (order A328xxUA-LC)
NOTES: 1. Tolerances on package height and width represent
allowable mold offsets. Dimensions given are
measured at the widest point (parting line).
2. Exact body and lead configuration at vendor’s option
within limits shown.
3. Height does not include mold gate flash.
4. Recommended minimum PWB hole diameter to clear
transition area is 0.035" (0.89 mm).
5. Where no tolerance is specified, dimension is nominal.
6. Supplied in bulk pack (500 pieces per bag).
1
2
3
0.108"
(2.74 mm)
0.620"
0.500"
(15.7 mm
12.7 mm)
0.100"
(2.5 mm)
Dwg. MH-026
NOTE: Lead-form dimensions are the nominals produced on the
forming equipment. No dimensional tolerance is implied or
guaranteed for bulk packaging (500 pieces per bag).
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11