A3508LU - Allegro MicroSystems, Inc.

3506, 3507, AND 3508

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMPERATURE OPERATION

The A3506–, A3507–, and A3508– comprise a family of sensitive,

temperature-stable linear Hall-effect sensors. 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

approximately 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 three devices in this series are

similar except for temperature stability over the operating temperature

range. See the Magnetic Characteristics table for complete, individual

device parametrics.

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.

These devices are supplied in a 3-pin mini-SIP “U” package or a

3-pin ultra-mini-SIP “UA” package.

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:

Operating Output Offset with Temp., ∆VOQ(∆T)

Temperature Range ±20 G ±35 G ±50 G

-20°C to +85°C — — A3508SU

A3508SUA

-40°C to +85°C — A3507EU —

A3507EUA

-40°C to +150°C A3506LU A3507LU —

A3506LUA A3507LUA

3506, 3507, AND

3508

MicroSystems, Inc.

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMPERATURE OPERATION

Dwg. PH-006

SUPPLY

GROUND

OUTPUT

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

Data Sheet

27501.1*

MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

3506, 3507, AND 3508

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMPERATURE OPERATION

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

FUNCTIONAL BLOCK DIAGRAM

600

400

200

20 60 100 140

AMBIENT TEMPERATURE in °C

ALLOWABLE PACKAGE POWER DISSIPATION in MILLIWATTS

Dwg. GH-046A

"U" PACKAGE

θJA

= 183°C/W

"UA" PACKAGE

θJA

= 206°C/W

40 80 120 160

700

500

300

100

Dwg. FH-011

GROUND

OUTPUT

ELECTRICAL CHARACTERISTICS over operating temperature range, at VCC = 5 V (unless otherwise noted).

Device Limits

Characteristic Symbol Type* Test Conditions Min. Typ. Max. Units

Supply Voltage VCC All Operating 4.5 5.0 5.5 V

Supply Current ICC All B = 0, VCC = 5.5 V, IO = 0 – – 10 mA

Quiescent VOQ 3506 B = 0, IO = 1 mA, TA = 25°C 2.25 2.50 2.75 V

Voltage Output 3507/08 2.0 2.5 3.0 V

3506 B = 0, IO = 1 mA 2.10 2.50 2.90 V

3507/08 1.8 2.5 3.2 V

Output Voltage VOH All B = +X†, IO = 1 mA 4.5 4.8 – V

VOL All B = -X†, IO = -1 mA – 0.2 0.5 V

Bandwidth (-3 dB) BW All 20 – – kHz

Output Resistance rOAll – 2.5 10 Ω

Wide-Band eoAll B = 0, BW = 10 Hz to 10 kHz, – 125 – µV

Output Noise TA = 25°C

Negative current is defined as coming out of (sourcing) the output.

* Complete part number includes the Allegro prefix “A”, and a suffix to identify operating temperature range

(S–, E–, or L–) and package type (–U or –UA). See first page for available combinations.

† 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.

3506, 3507, AND 3508

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMPERATURE OPERATION

MAGNETIC CHARACTERISTICS over operating temperature range, at VCC = 5 V, IO = 1 mA

(unless otherwise noted).

Part Numbers*

A3506L- A3507L- A3507E- A3508S-

Characteristic†Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Units

Operating Temp. Range, TA-40 – +150 -40 – +150 -40 – +85 -20 – +85 °C

Sensitivity at TA = 25°C 2.25 2.50 2.75 2.0 2.5 3.0 2.0 2.5 3.0 2.0 2.5 3.0 mV/G

over Oper. Temp. Range 2.00 2.50 3.00 1.7 2.5 3.3 1.7 2.5 3.3 1.7 2.5 3.3 mV/G

∆Sens(∆T)‡ at TA = Max. -2.5 2.5 7.5 -5.0 2.5 10 -6.3 1.2 8.7 -10 – 10 %

at TA = Min. -6.3 -1.3 3.7 -8.8 -1.3 6.2 -8.8 -1.3 6.2 -10 – 10 %

∆VOQ(∆T)§––±20 – – ±35 – – ±35 – – ±50 G

Ratiometry, ∆VOQ(∆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 – %

Magnetic flux density is measured at most sensitive area of device located 0.015" (0.38 mm) below the branded face of

the “U” package; 0.018" (0.46 mm) below the branded face of the “UA” package.

* Complete part number includes a suffix to indicate package type (–U or –UA).

† 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.

MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

3506, 3507, AND 3508

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMPERATURE OPERATION

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 (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) (1)

Sens(25°C)

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) (2)

1000 G

The stability of sensitivity as a function of tempera-

ture is defined as

∆Sens(∆T) = Sens(TA) – Sens(25°C) x 100% (3)

Sens(25°C)

CHARACTERISTICS DEFINITIONS

Ratiometry. The A3506–, 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) x 100% (4)

VCC / 5 V

and the per cent ratiometric change in sensitivity is defined

∆Sens(∆V) = Sens(VCC) / Sens(5V) x 100% (5)

VCC / 5 V

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+ = VO(500G) – VOQ x 100% (6)

2 (VO(250G) – VOQ)

Lin– = VO(-500G) – VOQ x 100% (7)

2 (VO(-250G) – VOQ)

and output symmetry as

Sym = VO(500G) – VOQ x 100% (8)

VOQ – VO(-500G)

3506, 3507, AND 3508

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMPERATURE OPERATION

SENSOR LOCATIONS

SUFFIX “U”

SUFFIX “UA”

APPLICATIONS INFORMATION

Calibrated linear Hall devices, which can be used to

determine the actual flux density presented to the sensor

in a particular application, are available.

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.

The nominal sensitivity is factory set to compensate

for the temperature coefficient of samarium-cobalt mag-

nets (-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

A3506/07/08– 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 sensor output voltage will

track changes in the LSB value.

Extensive applications information on Hall-effect

sensors and magnets is also available in the

Allegro

Integrated and Discrete Semiconductors Data Book

Application Note

27701.

1 32

Dwg. MH-002-11A

0.015"

0.38 mm

NOM

BRANDED

SURFACE

ACTIVE AREA DEPTH

0.073"

1.85 mm

0.091"

2.30 mm

1 32

Dwg. MH-011-6A

0.018"

0.46 mm

NOM

BRANDED

SURFACE

ACTIVE AREA DEPTH

0.082"

2.07 mm

0.055"

1.40 mm

TYPICAL CURRENT-SENSING APPLICATION

B ≈ N x 6 G/A

Dwg. AH-005

MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

3506, 3507, AND 3508

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMPERATURE OPERATION

RELATIVE DISTANCE

RELATIVE MAGNETIC FLUX DENSITY

Dwg. GH-048

RELATIVE OUTPUT VOLTAGE

-0.4 -0.2 0.2 0.4

GND

N S

0.19

RELATIVE DISTANCE (TOTAL EFFECTIVE AIR GAP)

RELATIVE MAGNETIC FLUX DENSITY

Dwg. GH-047

RELATIVE OUTPUT VOLTAGE

N S

SENSOR DEPTH

BELOW PACKAGE FACE

0.1 0.2 0.3 0.4 0.5

RELATIVE DISTANCE

RELATIVE MAGNETIC FLUX DENSITY

Dwg. GH-050

RELATIVE OUTPUT VOLTAGE

N S

0.05 0.10 0.15 0.20 0.25

EFFECTIVE

AIR GAP

0.21

EFFECTIVE AIR GAP = 0.050

EFFECTIVE AIR GAP = 0.075

EFFECTIVE AIR GAP = 0.095

RELATIVE DISTANCE

RELATIVE MAGNETIC FLUX DENSITY

Dwg. GH-049

RELATIVE OUTPUT VOLTAGE

-0.06 -0.04 0.04 0.06 0.08

GND

-0.08 0.10

-0.10

N S

S N

N S

S N

0.21

0.19

S N

N S

TYPICAL POSITION-SENSING APPLICATIONS

(Alnico 8, dimensions in inches)

3506, 3507, AND 3508

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMPERATURE OPERATION

PACKAGE DESIGNATOR U

Dimensions in Inches Dimensions in Millimeters

(Based on 1" = 25.4 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. Recommended minimum PWB hole diameter to clear transition area is 0.035" (0.89 mm).

Dwg. MH-003C in

0.063

0.059

0.018

0.015

0.016

0.050

1 2 3

0.100

45°

SEE NOTE

0.183

0.178

0.181

0.176

0.560

MIN

0.086

MAX

Dwg. MH-003C mm

1.60

1.50

0.46

0.38

0.41

1.27

1 2 3

2.54

45°

SEE NOTE

4.65

4.52

4.60

4.47

14.22

MIN

2.18

MAX

MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

3506, 3507, AND 3508

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMPERATURE OPERATION

PACKAGE DESIGNATOR UA

Dimensions in Inches Dimensions in Millimeters

(Based on 1" = 25.4 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.

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 design of its products. Components made under military approvals will be in

accordance with the approval requirements.

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 which may result from its use.

Dwg. MH-014C in

0.164

0.159

0.062

0.058

0.015

0.050

BSC

45°

0.600

MIN

0.016

0.085

MAX

45°

0.031

123

0.122

0.117

SEE NOTE

Dwg. MH-014C mm

4.17

4.04

1.57

1.47

0.38

1.27

BSC

45°

15.24

MIN

0.41

2.16

MAX

45°

0.79

123

3.10

2.97

SEE NOTE