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 responsibility for its use; nor
for any infringements of patents or other rights of third parties which may result from its use.
Recommended Substitutions:
Ratiometric, Linear Hall-Effect Sensors
for High-Temperature Operation
A3517 and A3518
For new customers or new applications:
for the A3517, please refer to the Allegro
A
1321
, and
for the A3518, please refer to the Allegro
A
1323
.
For existing programs only:
for the A3517, please refer to the Allegro
A3515
A3517LUA is replaced by the A3515LUA
A3517SUA is replaced by the A3515EUA
for the A3518, please refer to the Allegro
A3516
A3518LUA is replaced by the A3516LUA
A3518SUA is replaced by the A3516EUA
Date of status change: May 2, 2005
Deadline for receipt of LAST TIME BUY orders: December 31, 2005
These parts are in production but have been determined to be
LAST TIME BUY. This classification indicates that the product is
obsolete and notice has been given. Sale of this device is currently
restricted to existing customer applications. The device should not be
purchased for new design applications because of obsolescence in the
near future. Samples are no longer available.
Last Time Buy
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.
FEATURES
s
Temperature-Stable Quiescent Output Voltage
s
Precise Recoverability After Temperature Cycling
s
Output Voltage Proportional to Applied Magnetic Field
s
Ratiometric Rail-to-Rail Output
s
Improved Sensitivity
s
4.5 V to 5.5 V Operation
s
Immune to Mechanical Stress
s
Small Package Size
s
Solid-State Reliability
Always order by complete part number, e.g., A3517SUA .
RATIOMETRIC, LINEAR HALL-EFFECT SENSORS
FOR HIGH-TEMPERATURE OPERATION
Dwg. PH-006
1
SUPPLY
V
CC
GROUND
3
2
OUTPUT
X
Data Sheet
27501.11A*
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.
3517
AND
3518
3517
AND
3518
RATIOMETRIC,
LINEAR HALL-EFFECT SENSORS
FOR HIGH-TEMP. OPERATION
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
2
FUNCTIONAL BLOCK DIAGRAM
Dwg. FH-016A
GROUND
2
OUTPUT
3
1
X
DYNAMIC
OFFSET CANCELLATION
LOW-PASS
FILTER
+
+
SUPPLY
Vcc
Vcc/2
600
400
200
20
60
100
140
0
AMBIENT TEMPERATURE in
C
ALLOWABLE PACKAGE POWER DISSIPATION in MILLIWATTS
Dwg. GH-046-1A
Suffix "UA"
R
JA
= 165
C/W
40
80
120
180
700
500
300
100
160
800
Suffix "S"
Suffix "L"
Copyright 1997, 2002 Allegro MicroSystems, Inc.
3517
AND
3518
RATIOMETRIC,
LINEAR HALL-EFFECT SENSORS
FOR HIGH-TEMP. OPERATION
www.allegromicro.com
3
ELECTRICAL CHARACTERISTICS over operating temperature range, at V
CC
= 5 V (unless
otherwise noted).
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Supply Voltage
V
CC
Operating
4.5
5.0
5.5
V
Supply Current
I
CC
B = 0, V
CC
= 6 V, I
O
= 0
7.2
12
mA
Quiescent
V
OQ
B = 0, I
O
= 1 mA, T
A
= 25
C
2.2
2.5
2.8
V
Voltage Output
Output Voltage
V
OH
B = +X*, I
O
= 1 mA
4.7
V
V
OL
B = -X*, I
O
= -1 mA
0.2
V
Output
I
OLM
B = -X*, V
O
= 0
-1.0
-1.5
mA
Source Current Limit
Bandwidth (-3 dB)
BW
30
kHz
Clock Frequency
f
C
170
kHz
Output Resistance
r
O
I
O
-2 mA
1.0
Wide-Band
e
o
B = 0, BW = 10 Hz to 10 kHz,
400
V
Output Noise (rms)
I
O
-1 mA, C
O
= 100 pF
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.
3517
AND
3518
RATIOMETRIC,
LINEAR HALL-EFFECT SENSORS
FOR HIGH-TEMP. OPERATION
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
4
MAGNETIC CHARACTERISTICS over operating temperature range, at V
CC
= 5 V, I
O
= -1 mA
(unless otherwise noted).
Part Numbers
A3517SUA
A3517LUA
A3518SUA
A3518LUA
Characteristic*
Min. Typ. Max.
Min. Typ. Max.
Min. Typ. Max.
Min. Typ. Max.
Units
Operating Temp. Range, T
A
-20
+85
-40
+150
-20
+85
-40
+150
C
Sensitivity
at T
A
= 25
C
4.0
5.0
6.0
4.0
5.0
6.0
2.0
2.5
3.0
2.0
2.5
3.0
mV/G
Sens
(
T)
at T
A
= Max.
-5.0
2.5
10
-5.0
2.5
10
-5.0
2.5
10
-5.0
2.5
10
%
Sens
(
T)
at T
A
= Min.
-9.0
-1.3
6.0
-9.0
-1.3
6.0
-9.0
-1.3
6.0
-9.0
-1.3
6.0
%
V
OQ(
T)
20
20
20
20
G
Ratiometry,
V
OQ(
V)
100
100
100
100
%
Ratiometry,
Sens
(
V)
100
100
100
100
%
Positive Linearity, Lin+
100
100
100
100
%
Negative Linearity, Lin
100
100
100
100
%
Symmetry
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.
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