3517
AND
3518
RATIOMETRIC, LINEAR HALL-EFFECT SENSORS
FOR HIGH-TEMPERATURE OPERATION
The A3517xUA and A3518xUA are sensitive, temperature-stable linear
Hall-effect sensors with greatly improved offset characteristics. Ratiometric,
linear Hall-effect sensors provide a voltage output that is proportional to the
applied magnetic field and have a quiescent output voltage that is approxi-
mately 50% of the supply voltage. These magnetic sensors are ideal for use in
linear and rotary position sensing systems in the harsh environments of
automotive and industrial applications over extended temperatures to -40°C
and +150°C. The A3517xUA features an output sensitivity of 5 mV/G while
the A3518xUA has an output sensitivity of 2.5 mV/G. See the Magnetic
Characteristics table for complete, individual device parametrics.
Each BiCMOS monolithic circuit integrates a Hall element, improved
temperature-compensating circuitry to reduce the intrinsic sensitivity drift of
the Hall element, a small-signal high-gain amplifier, and a rail-to-rail low-
impedance output stage.
A proprietary dynamic offset cancelation technique, with an internal high-
frequency clock, reduces the residual offset voltage, which is normally caused
by device overmolding, temperature dependancies, and thermal stress. This
technique produces devices that have an extremely stable quiescent output
voltage, are immune to mechanical stress, and have precise recoverability after
temperature cycling. Many problems normally associated with low-level
analog signals are minimized by having the Hall element and amplifier in a
single chip. Output precision is obtained by internal gain and offset trim
adjustments during the manufacturing process.
These reduced-cost devices are supplied in a 3-pin ultra-mini-SIP “UA”
package only.
Data Sheet
27501.11A*
V
CC
1
X
2
3
GROUND
Dwg. PH-006
Pinning is shown viewed from branded side.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
.........................
8.0 V
Output Voltage, V
O
...........................
8.0 V
Output Sink Current, I
O
..................
10 mA
Magnetic Flux Density, B .........
Unlimited
Package Power Dissipation,
P
D
....................................
See Graph
Operating Temperature Range*, T
A
Suffix S– ....................
-20
°
C to +85
°
C
Suffix L– ....................
-40
°
C to +150
°
C
Storage Temperature Range,
T
S
.............................
-65
°
C to +170
°
C
* Infrequent excursions permitted; see
Applications Information.
OUTPUT
SUPPLY
FEATURES
s
s
s
s
s
s
s
s
s
Temperature-Stable Quiescent Output Voltage
Precise Recoverability After Temperature Cycling
Output Voltage Proportional to Applied Magnetic Field
Ratiometric Rail-to-Rail Output
Improved Sensitivity
4.5 V to 5.5 V Operation
Immune to Mechanical Stress
Small Package Size
Solid-State Reliability
Always order by complete part number, e.g.,
A3517SUA
.
3517
AND
3518
RATIOMETRIC,
LINEAR HALL-EFFECT SENSORS
FOR HIGH-TEMP. OPERATION
FUNCTIONAL BLOCK DIAGRAM
1
SUPPLY
Vcc
DYNAMIC
OFFSET CANCELLATION
LOW-PASS
FILTER
800
ALLOWABLE PACKAGE POWER DISSIPATION in MILLIWATTS
700
Suffix "–UA"
R
θJA
= 165°C/W
600
500
400
300
200
Suffix "S–"
100
Suffix "L–"
0
20
40
60
100
80
120
AMBIENT TEMPERATURE in
°
C
140
160
180
Dwg. GH-046-1A
2
+
–
X
3
OUTPUT
–
+
2
GROUND
Vcc/2
Dwg. FH-016A
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1997, 2002 Allegro MicroSystems, Inc.
3517
AND
3518
RATIOMETRIC,
LINEAR HALL-EFFECT SENSORS
FOR HIGH-TEMP. OPERATION
ELECTRICAL CHARACTERISTICS over operating temperature range, at V
CC
= 5 V (unless
otherwise noted).
Limits
Characteristic
Supply Voltage
Supply Current
Quiescent
Voltage Output
Output Voltage
Symbol
V
CC
I
CC
V
OQ
V
OH
V
OL
Output
Source Current Limit
Bandwidth (-3 dB)
Clock Frequency
Output Resistance
Wide-Band
Output Noise (rms)
I
OLM
BW
f
C
r
O
e
o
I
O
≤
-2 mA
B = 0, BW = 10 Hz to 10 kHz,
I
O
≤
-1 mA, C
O
= 100 pF
Test Conditions
Operating
B = 0, V
CC
= 6 V, I
O
= 0
B = 0, I
O
= 1 mA, T
A
= 25°C
B = +X*, I
O
= 1 mA
B = -X*, I
O
= -1 mA
B = -X*, V
O
= 0
Min.
4.5
–
2.2
Typ.
5.0
7.2
2.5
Max.
5.5
12
2.8
Units
V
mA
V
–
–
-1.0
4.7
0.2
-1.5
–
–
–
V
V
mA
–
–
–
–
30
170
1.0
400
–
–
–
–
kHz
kHz
Ω
µV
NOTE 1 – Typical data is at T
A
= 25°C and is for design information only.
NOTE 2 – Negative current is defined as coming out of (sourcing) the output.
* This test requires positive and negative fields sufficient to swing the output driver between fully OFF and saturated (ON),
respectively. It is NOT intended to indicate a range of linear operation.
www.allegromicro.com
3
3517
AND
3518
RATIOMETRIC,
LINEAR HALL-EFFECT SENSORS
FOR HIGH-TEMP. OPERATION
MAGNETIC CHARACTERISTICS over operating temperature range, at V
CC
= 5 V, I
O
= -1 mA
(unless otherwise noted).
Part Numbers
A3517SUA
Characteristic*
Operating Temp. Range, T
A
Sensitivity at T
A
= 25°C
∆Sens
(∆T)
at T
A
= Max.
∆Sens
(∆T)
at T
A
= Min.
∆V
OQ(∆T)†
Ratiometry,
∆V
OQ(∆V)
Ratiometry,
∆Sens
(∆V)
Positive Linearity, Lin+
Negative Linearity, Lin–
Symmetry
Min. Typ. Max.
-20
4.0
-5.0
–
5.0
2.5
+85
6.0
10
6.0
±20
–
–
–
–
–
A3517LUA
Min. Typ. Max.
-40
4.0
-5.0
–
5.0
2.5
+150
6.0
10
6.0
±20
–
–
–
–
–
A3518SUA
Min. Typ. Max.
-20
2.0
-5.0
–
2.5
2.5
+85
3.0
10
6.0
±20
–
–
–
–
–
A3518LUA
Min. Typ. Max.
-40
2.0
-5.0
–
2.5
2.5
+150
3.0
10
6.0
±20
–
–
–
–
–
Units
°C
mV/G
%
%
G
%
%
%
%
%
-9.0 -1.3
–
–
–
–
–
–
–
100
100
100
100
100
-9.0 -1.3
–
–
–
–
–
–
–
100
100
100
100
100
-9.0 -1.3
–
–
–
–
–
–
–
100
100
100
100
100
-9.0 -1.3
–
–
–
–
–
–
–
100
100
100
100
100
NOTE 1 – Magnetic flux density is measured at most sensitive area of device located 0.018" (0.46 mm) below the
branded face of the package.
NOTE 2 – 10 G = 1 mT, exactly.
NOTE 3 – Except for
∆Sens
(∆T)
, typical data is at T
A
= 25°C and is for design information only.
* See Characteristics Definitions for test conditions.
† This calculation (formula 1, next page) yields the device’s equivalent accuracy, over the operating temperature range, in
gauss.
4
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3517
AND
3518
RATIOMETRIC,
LINEAR HALL-EFFECT SENSORS
FOR HIGH-TEMP. OPERATION
CHARACTERISTICS DEFINITIONS
Quiescent Voltage Output.
In the quiescent state (no
magnetic field), the output is ideally equal to one-half of
the supply voltage over the operating voltage and tem-
perature range (V
OQ
≈
V
CC
/
2
). Due to internal component
tolerances and thermal considerations, there is a tolerance
on the quiescent voltage output and on the quiescent
voltage output as a function of supply voltage and ambient
temperature. For purposes of specification, the quiescent
voltage output as a function of temperature is defined as
∆V
OQ(∆T)
=
V
OQ(TA)
– V
OQ(25°C)
Sens
(25°C)
Ratiometry.
The A3517xUA and A3518xUA feature a
ratiometric output. The quiescent voltage output and
sensitivity are proportional to the supply voltage
(ratiometric).
The per cent ratiometric change in the quiescent
voltage output is defined as
∆V
OQ(∆V)
=
(1)
and the per cent ratiometric change in sensitivity is defined
as
∆Sens
(∆V)
=
Sens
(VCC)
/ Sens
(5V)
V
CC
/ 5 V
V
OQ(VCC)
/ V
OQ(5V)
V
CC
/ 5 V
x 100%
(4)
This calculation yields the device’s equivalent
accuracy, over the operating temperature range, in gauss.
Sensitivity.
The presence of a south-pole magnetic field
perpendicular to the package face (the branded surface)
will increase the output voltage from its quiescent value
toward the supply voltage rail by an amount proportional to
the magnetic field applied. Conversely, the application of
a north pole will decrease the output voltage from its
quiescent value. This proportionality is specified as the
sensitivity of the device and is defined as
V
O(500G)
– V
O(-500G)
1000 G
x 100%
(5)
Linearity and Symmetry.
The on-chip output stage is
designed to provide a linear output to within 500 mV of
either rail with a supply voltage of 5 V. This is equivalent
to approximately
±800
gauss of ambient field. Although
application of stronger magnetic fields will not damage
these devices, it will force the output into a non-linear
region. Linearity in per cent is measured and defined as
V
O(500G)
– V
OQ
2 (V
O(250G)
– V
OQ
)
V
O(-500G)
– V
OQ
2 (V
O(-250G)
– V
OQ
)
Sens =
(2)
Lin+ =
x 100%
(6)
The stability of sensitivity as a function of tempera-
ture is defined as
Lin– =
∆Sens
(∆T)
=
Sens
(TA)
– Sens
(25°C)
Sens
(25°C)
x 100%
(3)
x 100%
(7)
and output symmetry as
V
O(500G)
– V
OQ
V
OQ
– V
O(-500G)
Sym =
x 100%
(8)
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