3134
BIPOLAR HALL-EFFECT SWITCH
FOR HIGH-TEMPERATURE OPERATION
This low-hysteresis bipolar Hall-effect switch is an extremely
temperature-stable and stress-resistant sensor especially suited for
operation over extended temperature ranges to +150°C. Superior
high-temperature performance is made possible through a novel Schmitt
trigger circuit that maintains operate and release point stability by
compensating for temperature changes in the Hall element. Additionally,
internal compensation provides magnetic switch points that become more
sensitive with temperature, hence offsetting the usual degradation of the
magnetic field with temperature. Its low hysteresis makes this device
ideal for detecting small changes in magnetic field strength or for use
with inexpensive magnets.
The device includes on a single silicon chip a voltage regulator,
quadratic Hall-voltage generator, temperature compensation circuit,
signal amplifier, Schmitt trigger, and a buffered open-collector output to
sink up to 25 mA. The on-board regulator permits operation with supply
voltages of 4.5 volts 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
suffix ‘L–’ is -40°C to +150°C. Two package styles provide a magneti-
cally optimized package for most applications. Suffix ‘–LT’ is a minia-
ture SOT89/TO-243AA transistor package for surface-mount applica-
tions while suffix ‘–UA’ is a three-lead ultra-mini-SIP.
Data Sheet
27631.4D
V
X
CC
1
2
3
GROUND
Dwg. PH-003A
Pinning is shown viewed from branded side.
ABSOLUTE MAXIMUM RATINGS
at T
A
= +25
°
C
Supply Voltage, V
CC
.............................
30 V
Reverse Battery Voltage, V
RCC
..........
-30 V
Magnetic Flux Density, B ..........
Unlimited
Output OFF Voltage, V
OUT
..................
30 V
Reverse Output Voltage, V
OUT
...........
-0.5 V
Continuous Output Current,
I
OUT
............................................
25 mA
Operating Temperature Range, T
A
Suffix ‘E–’ ..................
-40
°
C to +85
°
C
Suffix ‘L–’ ................
-40
°
C to +150
°
C
Storage Temperature Range,
T
S
..............................
-65
°
C to +170
°
C
OUTPUT
SUPPLY
FEATURES
s
Superior Temperature Stability
s
Operation From Unregulated Supply
s
Open-Collector 25 mA Output
s
Reverse Battery Protection
s
Activate With Small, Commercially Available Permanent Magnets
s
Solid-State Reliability
s
Small Size
s
Resistant to Physical Stress
Always order by complete part number, e.g.,
A3134ELT
.
3134
LOW-HYSTERESIS
BIPOLAR HALL-EFFECT SWITCH
FOR HIGH-TEMP. OPERATION
FUNCTIONAL BLOCK DIAGRAM
1
V
CC
REG.
X
3
OUTPUT
GROUND
2
Dwg. FH-005-3
ELECTRICAL CHARACTERISTICS over operating temperature range, at V
CC
= 12 V.
Limits
Characteristic
Supply Voltage
Output Saturation Voltage
Output Leakage Current
Supply Current
Output Rise Time
Output Fall Time
Symbol
V
CC
V
OUT(SAT)
I
OFF
I
CC
t
r
t
f
Test Conditions
Operating
I
OUT
= 20 mA, B > B
OP
V
OUT
= 24 V, B < B
RP
B < B
RP
(Output OFF)
B > B
OP
(Output ON)
R
L
= 820
Ω,
C
L
= 20 pF
R
L
= 820
Ω,
C
L
= 20 pF
Min.
4.5
—
—
—
—
—
—
Typ.
—
175
0.05
3.2
5.0
100
100
Max.
24
400
1.0
9.0
—
—
—
Units
V
mV
µA
mA
mA
ns
ns
MAGNETIC CHARACTERISTICS over oper. temp. and oper. supply voltage ranges.
Limits
Characteristic
Operate Point
Release Point
Hysteresis
Symbol
B
OP
B
RP
B
hys
Test Conditions
Min.
-40
-50
5.0
Typ.
8.5
-19
27
Max.
60
50
55
Units
G
G
G
NOTES: B
OP
= operate point (output turns ON); B
RP
= release point (output turns OFF); B
hys
= hysteresis (B
OP
- B
RP
).
As used here, negative flux densities are defined as less than zero (algebraic convention).
Typical values are at T
A
= +25°C and V
CC
= 12 V.
1 gauss (G) is exactly equal to 0.1 millitesla (mT).
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1995, 2003 Allegro MicroSystems, Inc.
3134
LOW-HYSTERESIS
BIPOLAR HALL-EFFECT SWITCH
FOR HIGH-TEMP. OPERATION
TYPICAL OPERATING CHARACTERISTICS
SWITCH POINTS
40
50
HYSTERESIS
40
V
CC
= 4.5 V–24 V
20
SWITCH POINT IN GAUSS
OPERATE POINT
HYSTERESIS IN GAUSS
30
0
20
-20
RELEASE POINT
V
CC
= 4.5 V–24 V
10
-40
-50
0
-25
0
25
50
75
100
125
150
-50
-25
0
25
50
75
100
125
150
Dwg. GH-051
AMBIENT TEMPERATURE IN
°
C
Dwg. GH-052
AMBIENT TEMPERATURE IN
°
C
OUTPUT SATURATION VOLTAGE
300
5.0
SUPPLY CURRENT
I
OUT
= 20 mA
V
CC
= 4.5–24 V
B < B
RP
4.0
SATURATION VOLTAGE IN mV
200
SUPPLY CURRENT IN mA
V
CC
= 24 V
3.0
V
CC
= 4.5 V
V
CC
= 12 V
100
2.0
0
-50
1.0
-25
0
25
50
75
100
125
150
-50
-25
0
25
50
75
100
125
150
AMBIENT TEMPERATURE IN
°
C
Dwg. GH-029
AMBIENT TEMPERATURE IN
°
C
Dwg. GH-053
www.allegromicro.com
3134
LOW-HYSTERESIS
BIPOLAR HALL-EFFECT SWITCH
FOR HIGH-TEMP. OPERATION
SENSOR LOCATIONS
(±0.005" [0.13 mm] die placement)
Suffix “LT”
ACTIVE AREA DEPTH
0.0305"
0.775 mm
NOM
0.090"
2.27 mm
0.050"
1.27 mm
APPLICATIONS INFORMATION
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.
All are provided in
Allegro Electronic Data Book,
AMS-702. or at
www.allegromicro.com
A
1
2
3
OPERATION
Dwg. MH-008-4C
Suffix “UA”
ACTIVE AREA DEPTH
0.0195"
0.50 mm
NOM
0.083"
2.10 mm
The output of these devices (pin 3) switches low when the magnetic field
at the Hall sensor exceeds the operate point threshold (B
OP
). At this point, the
output voltage is V
OUT(SAT)
. When the magnetic field is reduced to below the
release point (B
RP
) the device output goes high. Note especially that release
can occur when the magnetic field is removed but to ensure release, a field
reversal is required. The difference in the magnetic operate and release points
is called the hysteresis (B
hys
) 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 the device in the absence of a magnetic field (less than B
OP
and higher than B
RP
) will allow in indeterminate output state. The correct state
is warranted after the first excursion beyond B
OP
or B
RP
.
0.060"
1.51 mm
A
BRANDED
SURFACE
1
2
3
Dwg. MH-011-4C
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 infringe-
ments of patents or other rights of third parties that may result from its use.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3134
LOW-HYSTERESIS
BIPOLAR HALL-EFFECT SWITCH
FOR HIGH-TEMP. OPERATION
PACKAGE DESIGNATOR ‘LT’
(SOT89/TO-243AA)
Dimensions in Inches
(for reference only)
Dimensions in Millimeters
(controlling dimensions)
0.181
0.173
0.072
0.064
0.167
0.155
0.102
0.090
0.063
0.055
0.0173
0.0138
4.60
4.40
1.83
1.62
4.25
3.94
2.60
2.29
1.60
1.40
0.44
0.35
1
2
3
0.090
0.084
1
2
3
2.29
2.13
0.047
0.035
0.059
BSC
0.0189
0.0142
0.0221
0.0173
0.118
BSC
Dwg. MA-009-3A in
1.20
0.89
1.50
BSC
0.48
0.36
0.56
0.44
3.00
BSC
Dwg. MA-009-3A mm
0.098
0.079
B
A
0.031
0.102
0.181
3 0.047
0.031
TYP
2.5
2.0
B
A
0.8
2.6
4.6
1.2
0.8
TYP
1
0.028
TYP
2
1
0.7
TYP
2
3
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
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 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.
www.allegromicro.com
京公网安备 11010802033920号
EEWORLD
