A3507 and A3508: Ratiometric, Linear Hall-Effect Sensor ICs for High-Temperature Operation

AND
Data Sheet
27501.1D
3507
3508
RATIOMETRIC, LINEAR HALL-EFFECT SENSOR ICS
FOR HIGH-TEMPERATURE OPERATION
The A3507– and A3508– are sensitive, temperature-stable linear
Hall-effect sensor ICs. Ratiometric, linear Hall-effect circuits provide a
voltage output that is proportional to the applied magnetic field and have
a quiescent output voltage that is approximately 50% of the supply
voltage. These devices 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 two devices are similar except for temperature stability over the
operating temperature range. See the Magnetic Characteristics table for
complete, individual device parametrics.
X
T
C
.
U
Y
D
L
O
N
R
P EO
D
C
E
N
U
E
N R
I
E
T
F
N
E
O
R
C
S
R
I
D FO
—
1
2
3
GROUND
OUTPUT
CC
SUPPLY
V
Dwg. PH-006
Each monolithic circuit integrates a quadratic 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. 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.
The first character of the part number suffix determines the device
operating temperature range: suffix ‘S–’ is for -20°C to +85°C, suffix
‘E–’ is for -40°C to +85°C, and suffix ‘L–’ is for -40°C to +150°C.
These devices are supplied in a 3-pin ultra-mini-SIP ‘–UA’ package.
Pinning is shown viewed from branded side.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VCC . . . . . . . . . . . . 6.0 V
Output Voltage, VO . . . . . . . . . . . . . 6.0 V
Output Sink Current, IO . . . . . . . . 5.0 mA
Magnetic Flux Density, B . . . . Unlimited
Package Power Dissipation,
PD . . . . . . . . . . . . . . . . . . . . See Graph
Operating Temperature Range, TA
Suffix ‘S–’ . . . . . . . . . . . . -20°C to +85°C
Suffix ‘E–’ . . . . . . . . . . . . -40°C to +85°C
Suffix ‘L–’ . . . . . . . . . . . -40°C to +150°C
Storage Temperature Range,
TS . . . . . . . . . . . . . . . -65°C to +170°C
FEATURES
■ Output Voltage Proportional to Applied Magnetic Field
■ Ratiometric Rail-to-Rail Output
■ Improved Sensitivity
■ Superior Temperature Stability
■ 4.5 V to 5.5 V Operation
■ Small Package Size
■ Solid-State Reliability
Always order by complete part number, e.g., A3507EUA .
3507 AND 3508
RATIOMETRIC,
LINEAR HALL-EFFECT SENSOR ICS
FOR HIGH-TEMP. OPERATION
700
1 VCC
3
X
OUTPUT
2 GROUND
Dwg. FH-011
ALLOWABLE PACKAGE POWER DISSIPATION in MILLIWATTS
FUNCTIONAL BLOCK DIAGRAM
600
"U" PACKAGE
RθJA = 183°C/W
500
400
300
"UA" PACKAGE
RθJA = 206°C/W
200
100
0
20
40
60
100
80
AMBIENT TEMPERATURE in ° C
120
140
160
Dwg. GH-046A
ELECTRICAL CHARACTERISTICS over operating temperature range, at VCC = 5 V (unless otherwise
noted).
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Supply Voltage
VCC
Operating
4.5
5.0
5.5
V
Supply Current
ICC
B = 0, VCC = 5.5 V, IO = 0
–
–
10
mA
Quiescent
Voltage Output
VOQ
B = 0, IO = 1 mA, TA = 25°C
2.0
2.5
3.0
V
B = 0, IO = 1 mA
1.8
2.5
3.2
V
Output Voltage
VOH
B = +X*, IO = 1 mA
4.5
4.8
–
V
VOL
B = -X*, IO = -1 mA
–
0.2
0.5
V
Bandwidth (-3 dB)
BW
20
–
–
kHz
Output Resistance
rO
–
2.5
10
Ω
Wide-Band
Output Noise
eo
–
125
–
µV
B = 0, BW = 10 Hz to 10 kHz,
TA = 25°C
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.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1994, 2001, Allegro MicroSystems, Inc.
3507 AND 3508
RATIOMETRIC,
LINEAR HALL-EFFECT SENSOR ICS
FOR HIGH-TEMP. OPERATION
MAGNETIC CHARACTERISTICS over operating temperature range, at VCC = 5 V, IO = 1 mA
(unless otherwise noted).
Part Numbers
A3507LUA
A3507EUA
A3508SUA
Characteristic*
Min.
Typ.
Max.
Min.
Typ.
Max.
Min.
Typ.
Max.
Units
Operating Temp. Range, T A
-40
–
+150
-40
–
+85
-20
–
+85
°C
Sensitivity at TA = 25°C
2.0
2.5
3.0
2.0
2.5
3.0
2.0
2.5
3.0
mV/G
1.7
2.5
3.3
1.7
2.5
3.3
1.7
2.5
3.3
mV/G
-5.0
2.5
10
-6.3
1.2
8.7
-10
–
10
%
-8.8
-1.3
6.2
-8.8
-1.3
6.2
-10
–
10
%
∆VOQ(∆T)‡
–
–
±35
–
–
±35
–
–
±50
G
Ratiometry, ∆VOQ(∆V)
–
100
–
–
100
–
–
100
–
%
Ratiometry, ∆Sens(∆V)
–
100
–
–
100
–
–
100
–
%
Positive Linearity, Lin+
–
100
–
–
100
–
–
100
–
%
Negative Linearity, Lin–
–
100
–
–
100
–
–
100
–
%
Symmetry
–
100
–
–
100
–
–
100
–
%
over Oper. Temp. Range
∆Sens(∆T)† at TA = Max.
at TA = Min.
Magnetic flux density is measured at most sensitive area of device located 0.018" (0.46 mm) below the branded face of the “UA”
package.
* See Characteristics Definitions for test conditions.
† The nominal sensitivity temperature stability is designed to compensate for the temperature coefficient of samarium-cobalt
magnets (-0.02%/°C).
‡ This calculation (formula 1, next page) yields the device’s equivalent accuracy, over the operating temperature range, in gauss.
www.allegromicro.com
3507 AND 3508
RATIOMETRIC,
LINEAR HALL-EFFECT SENSOR ICS
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 temperature range (VOQ
∪ VCC/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
∆VOQ(∆T) =
VOQ(TA) – VOQ(25°C)
Sens(25°C)
(1)
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
Sens =
VO(500G) – VO(-500G)
1000 G
(2)
The stability of sensitivity as a function of temperature is
defined as
∆Sens(∆T) =
Sens(TA) – Sens(25°C)
Sens(25°C)
x 100%
(3)
Ratiometry. The A3507– and A3508– 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
∆VOQ(∆V) =
VOQ(VCC) / VOQ(5V)
VCC / 5 V
x 100%
(4)
and the per cent ratiometric change in sensitivity is defined as
Sens(VCC) / Sens(5V)
∆Sens(∆V) =
VCC / 5 V
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
Lin+ =
Lin– =
VO(500G) – VOQ
2 (VO(250G) – VOQ)
VO(-500G) – VOQ
2 (VO(-250G) – VOQ)
x 100%
(6)
x 100%
(7)
and output symmetry as
Sym =
VO(500G) – VOQ
VOQ – VO(-500G)
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
x 100%
(8)
3507 AND 3508
RATIOMETRIC,
LINEAR HALL-EFFECT SENSOR ICS
FOR HIGH-TEMP. OPERATION
APPLICATIONS INFORMATION
Calibrated linear Hall devices, which can be used to
determine the actual flux density presented to the element in a
particular application, are available.
ELEMENT LOCATION
ACTIVE AREA DEPTH
0.0195"
0.50 mm
NOM
For safe, reliable operation, the output should not be
pulled above the supply voltage or pulled below the device
ground.
For optimum performance, a 100 pF capacitor between
the output and ground should be added.
0.055"
1.40 mm
A
BRANDED
SURFACE
The nominal sensitivity is factory set to compensate for
the temperature coefficient of samarium-cobalt magnets
(-0.02%/°C).
The ratiometric feature is especially valuable when these
devices are used with an analog-to-digital converter. A/D
converters typically derive their LSB step size by ratioing off a
reference voltage line. If the reference voltage varies, the LSB
will vary proportionally. This is a major error source in many
sensing systems. The A3507/08– can eliminate this source of
error by their ratiometric operation. Because their gain and
offsets are proportional to the supply voltage, if they are
powered from the A/D reference voltage, the device output
voltage will track changes in the LSB value.
0.082"
2.07 mm
1
2
3
Dwg. MH-011-6B
TYPICAL CURRENT-SENSING APPLICATION
B ≈ N x 6.9 G/A
Hall-effect applications information is available in the
application note “Linear Hall-Effect Sensor ICs” (AN 27702),
which can be found in the latest issue of Allegro Electronic
Data Book, AMS-702, or at
www.allegromicro.com
www.allegromicro.com
Dwg. AH-005A
3507 AND 3508
RATIOMETRIC,
LINEAR HALL-EFFECT SENSOR ICS
FOR HIGH-TEMP. OPERATION
TYPICAL POSITION-SENSING APPLICATIONS
(Alnico 8, dimensions in inches)
+
+
VCC
VCC
0.21
D
N
S
S
N
N
S
S
N
RELATIVE OUTPUT VOLTAGE
D
0
VOQ
0.19
S N
RELATIVE OUTPUT VOLTAGE
S
RELATIVE MAGNETIC FLUX DENSITY
N
RELATIVE MAGNETIC FLUX DENSITY
ELEMENT DEPTH
BELOW PACKAGE FACE
N S
D
0
0
0.1
0.2
0.3
0.4
RELATIVE DISTANCE (TOTAL EFFECTIVE AIR GAP)
+
-
VOQ
0.5
-0.10
-0.08
-0.06
Dwg. GH-047
-0.04
0
0.04
RELATIVE DISTANCE
0
RELATIVE DISTANCE
0.2
0.4
GND
Dwg. GH-048
N
S
D
RELATIVE MAGNETIC FLUX DENSITY
0.21
RELATIVE OUTPUT VOLTAGE
VOQ
RELATIVE OUTPUT VOLTAGE
RELATIVE MAGNETIC FLUX DENSITY
EFFECTIVE AIR GAP = 0.050
S
0
-0.2
Dwg. GH-049
EFFECTIVE
AIR GAP
D
-0.4
GND
0.10
VCC
0.19
-
0.08
+
VCC
N
0.06
EFFECTIVE AIR GAP = 0.075
EFFECTIVE AIR GAP = 0.095
0
0
0.05
0.10
0.15
RELATIVE DISTANCE
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
0.20
VOQ
0.25
Dwg. GH-050
3507 AND 3508
RATIOMETRIC,
LINEAR HALL-EFFECT SENSOR ICS
FOR HIGH-TEMP. OPERATION
Dimensions in Inches
(controlling dimensions)
Dimensions in Millimeters
(for reference only)
0.164
0.159
4.17
4.04
0.062
0.058
45°
0.122
0.117
0.085
MAX
2
3
0.031
2.16
MAX
0.0173
0.0138
0.640
0.600
0.0189
0.0142
SEE NOTE
BSC
2.
3.
4.
5.
45°
1
2
3
0.79
0.44
0.35
16.26
15.24
0.48
0.36
SEE NOTE
0.050
NOTES: 1.
3.10
2.97
45°
1
1.57
1.47
45°
1.27
Dwg. MH-014E in
BSC
Tolerances on package height and width represent allowable mold offsets Dimensions given are
measured at the widest point (parting line).
Exact body and lead configuration at vendor’s option within limits shown.
Height does not include mold gate flash.
Recommended minimum PWB hole diameter to clear transition area is 0.035" (0.89 mm).
Where no tolerance is specified, dimension is nominal.
www.allegromicro.com
Dwg. MH-014E mm
3507 AND 3508
RATIOMETRIC,
LINEAR HALL-EFFECT SENSOR ICS
FOR HIGH-TEMP. OPERATION
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.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
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