A3185ELTTR - Allegro MicroSystems, Inc.

HALL-EFFECT LATCHES

FOR HIGH-TEMPERATURE OPERATION

These Hall-effect latches are extremely temperature-stable and stress-

resistant sensors 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 symmetry by compensating for temperature changes in the Hall ele-

ment. Additionally, internal compensation provides magnetic switch points

that become more sensitive with temperature, hence offsetting the usual

degradation of the magnetic field with temperature. The symmetry capability

makes these devices ideal for use in pulse-counting applications where duty

cycle is an important parameter. The four basic devices (3185, 3187, 3188,

and 3189) are identical except for magnetic switch points.

Each device includes on a single silicon chip a voltage regulator, qua-

dratic 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 3.8

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 for -40°C to +150°C. Three package styles provide a magnetically

optimized package for most applications. Suffix ‘–LT’ is a miniature SOT89/

TO-243AA transistor package for surface-mount applications; suffix ‘–UA’ is

a three-lead ultra-mini-SIP.

Data Sheet

27609.2B*

ABSOLUTE MAXIMUM RATINGS

at T

A = +25°C

Supply Voltage, VCC ............................ 30 V

Reverse Battery Voltage, VRCC ........... -30 V

Magnetic Flux Density, B ........... Unlimited

Output OFF Voltage, VOUT .................. 30 V

Reverse Output Voltage, VOUT .......... -0.5 V

Continuous Output Current, IOUT ..... 25 mA

Operating Temperature Range, TA

Suffix ‘E–’ ................... -40°C to +85°C

Suffix ‘L–’ ................. -40°C to +150°C

Storage Temperature Range,

TS............................... -65°C to +170°C

FEATURES

■ Symmetrical Switch Points

■ Superior Temperature Stability

■ Operation From Unregulated Supply

■ Open-Collector 25 mA Output

■ Reverse Battery Protection

■ Activate With Small, Commercially Available Permanent Magnets

■ Solid-State Reliability

■ Small Size

■ Resistant to Physical Stress

Pinning is shown viewed from branded side.

Always order by complete part number: the prefix ‘A’ + the basic four-digit

part number + a suffix to indicate operating temperature range +

a suffix to indicate package style, e.g., A3185ELT .

3185

THRU

3189

Dwg. PH-003A

SUPPLY

VCC

GROUND

OUTPUT

3185

THRU

3189

HALL-EFFECT LATCHES

FOR HIGH-TEMPERATURE

OPERATION

115 Northeast Cutoff, Box 15036

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

ELECTRICAL CHARACTERISTICS over operating temperature range, at VCC = 12 V.

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Supply Voltage VCC Operating 3.8 — 24 V

Output Saturation Voltage VOUT(SAT) IOUT = 20 mA, B > BOP — 175 400 mV

Output Leakage Current IOFF VOUT = 24 V, B < BRP — 0.05 5.0 µA

Supply Current ICC B < BRP (Output OFF) — 4.75 8.0 mA

B > BOP (Output ON) — 5.7 — mA

Output Rise Time trRL = 820 Ω, CL = 20 pF — 100 — ns

Output Fall Time tfRL = 820 Ω, CL = 20 pF — 100 — ns

MAGNETIC CHARACTERISTICS in gauss over operating supply voltage range.

Part Numbers*

A3185 A3187 A3188 A3189

Characteristic Min. Max. Min. Max. Min. Max. Min. Max.

BOP at TA = 25°C 170 270 50 150 100 180 50 230

over operating temp. range 140 300 50 175 80 200 50 250

BRP at TA = 25°C -270 -170 -150 -50 -180 -100 -230 -50

over operating temp. range -300 -140 -175 -50 -200 -80 -250 -50

Bhys at TA = 25°C 340 540 100 300 200 360 100 460

over operating temp. range 280 600 100 350 160 400 100 500

FUNCTIONAL BLOCK DIAGRAM

NOTES: BOP = operate point (output turns ON); BRP = release point (output turns OFF); Bhys = hysteresis (BOP - BRP).

As used here, negative flux densities are defined as less than zero (algebraic convention).

*Complete part number includes a suffix to identify operating temperature range (E or L) and package type ( LT or UA).

VCC

REG.

Dwg. FH-005-3

GROUND

OUTPUT

3185

THRU

3189

HALL-EFFECT LATCHES

FOR HIGH-TEMPERATURE

OPERATION

www.allegromicro.com

TYPICAL OPERATING CHARACTERISTICS

A3185* SWITCH POINTS A3187* SWITCH POINTS

* Complete part number includes a suffix denoting operating temperature range (E or L) and package type (LT or UA).

OUTPUT SATURATION VOLTAGE

SUPPLY CURRENT

OPERATE POINT

0 50 100

AMBIENT TEMPERATURE IN °°

°°C

-50

Dwg. GH-027

SWITCH POINT IN GAUSS

100

-50

-100

OPERATE POINT

RELEASE POINT

V = 12 V

150

-150 -25 25 75 125

0 25 50 75 100

AMBIENT TEMPERATURE IN °°

°°C

-50

Dwg. GH-028

125

-25

V = 12 V

B ≤ B

SUPPLY CURRENT IN mA

7.0

6.0

5.0

4.0

B ≥ B

150

0255075

100

300

AMBIENT TEMPERATURE IN °°

°°C

200

100

-50

Dwg. GH-029

SATURATION VOLTAGE IN mV

150

-25 125

I = 20 mA

V = 4.5–24 V

OUT

10 15 20 25

SUPPLY VOLTAGE IN VOLTS

Dwg. GH-037

CHANGE IN OPERATE POINT IN GAUSS

-5.0

5.0

T = +25°C

0 50 100

AMBIENT TEMPERATURE IN °°

°°C

-50

Dwg. GH-026

SWITCH POINT IN GAUSS

100

200

-100

-200

OPERATE POINT

RELEASE POINT

V = 12 V

150

300

-300 -25 25 75 125

10 15 20 25

SUPPLY VOLTAGE IN VOLTS

Dwg. GH-030

SUPPLY CURRENT IN mA

2.0

4.0

6.0

8.0

B ≥ B

B ≤ B

T = +25°C

3185

THRU

3189

HALL-EFFECT LATCHES

FOR HIGH-TEMPERATURE

OPERATION

115 Northeast Cutoff, Box 15036

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

SENSOR LOCATIONS

(±0.005” [0.13 mm] die placement)

Allegro

Package Designators “LT”

1 32

Dwg. MH-008-4C

0.0305"

0.775 mm

NOM

ACTIVE AREA DEPTH

0.050"

1.27 mm

0.090"

2.27 mm

Package Designators “UA”

1 32

Dwg. MH-011-4C

0.0195"

0.50 mm

NOM

BRANDED

SURFACE

ACTIVE AREA DEPTH

0.083"

2.10 mm

0.060"

1.51 mm

The simplest form of magnet that will operate these devices is a ring

magnet, as shown below. Other methods of operation are possible.

Dwg. A-11,899

OPERATION

In operation, the output transistor is OFF until the strength of the mag-

netic field perpendicular to the surface of the chip exceeds the threshold or

operate point (BOP). When the field strength exceeds BOP, the output transis-

tor switches ON and is capable of sinking 25 mA of current.

The output transistor switches OFF when magnetic field reversal results

in a magnetic flux density below the OFF threshold (BRP). This is illustrated

in the transfer characteristics graph (A3187* shown).

Note that the device latches; that is, a south pole of sufficient strength

will turn the device ON. Removal of the south pole will leave the device ON.

The presence of a north pole of sufficient strength is required to turn the

device OFF. Powering up in the absence of a magnetic field (less than BOP

and higher than BRP) will allow an indeterminate output state. The correct

state is warranted after the first excursion beyond BOP or BRP.

APPLICATIONS INFORMATION

Extensive applications information on magnets and Hall-effect sensors is

also available in the Allegro Integrated and Discrete Semiconductors Data

Book or Application Note 27701.

30 V

MAX

0+B

OUTPUT VOLTAGE IN VOLTS

FLUX DENSITY Dwg. GH-034-4

-B

OUT(SAT)

Although sensor location is accurate to three

sigma for a particular design, product improve-

ments may result in small changes to sensor

location.

3185

THRU

3189

HALL-EFFECT LATCHES

FOR HIGH-TEMPERATURE

OPERATION

www.allegromicro.com

Dwg. MA-009-3A in

123

0.072

0.064

0.167

0.155

0.059

BSC

0.0189

0.0142

0.047

0.035

0.102

0.090

0.063

0.055 0.0173

0.0138

0.090

0.084

0.0221

0.0173

0.118

BSC

0.181

0.173

Dwg. MA-009-3A mm

123

4.60

4.40

1.83

1.62

4.25

3.94

1.50

BSC

0.48

0.36

1.20

0.89

2.60

2.29

1.60

1.40 0.44

0.35

2.29

2.13

0.56

0.44

3.00

BSC

PACKAGE DESIGNATOR ‘LT’

(SOT89/TO-243AA)

Dimensions in Inches

(for reference only)

Dimensions in Millimeters

(controlling dimensions)

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.

0.098

0.031

0.102

0.047

0.181

0.079

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

0.028

TYP 0.031

TYP

2.5

0.8

2.6

1.2

4.6

2.0

Dwg. MA-012-3 mm

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

0.7

TYP

0.8

TYP

3185

THRU

3189

HALL-EFFECT LATCHES

FOR HIGH-TEMPERATURE

OPERATION

115 Northeast Cutoff, Box 15036

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

Dimensions in Inches

(controlling dimensions)

Dimensions in Millimeters

(for reference only)

PACKAGE DESIGNATOR ‘UA’

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).

5. Where no tolerance is specified, dimension is nominal.

6. Supplied in bulk pack (500 pieces per bag).

Dwg. MH-014E in

0.164

0.159

0.062

0.058

0.0173

0.0138

0.050

BSC

45°

0.640

0.600

0.0189

0.0142

0.085

MAX

45°

0.031

123

0.122

0.117

SEE NOTE

Dwg. MH-014E mm

4.17

4.04

1.57

1.47

0.44

0.35

1.27

BSC

45°

16.26

15.24

0.48

0.36

2.16

MAX

45°

0.79

123

3.10

2.97

SEE NOTE

Radial Lead Form (order A318xxUA-LC)

NOTE: Lead-form dimensions are the nominals produced on the

forming equipment. No dimensional tolerance is implied or

guaranteed for bulk packaging (500 pieces per bag).

0.620"

0.500"

(15.7 mm

12.7 mm)

0.100"

(2.5 mm)

Dwg. MH-026

0.108"

(2.74 mm)

123

3185

THRU

3189

HALL-EFFECT LATCHES

FOR HIGH-TEMPERATURE

OPERATION

www.allegromicro.com

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. How-

ever, 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.

3185

THRU

3189

HALL-EFFECT LATCHES

FOR HIGH-TEMPERATURE

OPERATION

115 Northeast Cutoff, Box 15036

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

HALL-EFFECT SENSORS

LATCHING HALL-EFFECT DIGITAL SWITCHES

Partial Operate Release Hysteresis Replaces

Part Point (G) Point (G) (G) Oper. and

Number

Over Oper. Voltage & Temp. Range

Temp. Packages Comments

UGN3175 15 to 180 -180 to -15 >80 (Typ 180) S LT, UA

UGN3177 25 to 150 -150 to -25 >50 (Typ 180) S LT, UA

A3185x 140 to 300 -300 to -140 280 to 600 E/L LT, UA

A3187x 50 to 175 -175 to -50 100 to 350 E/L LT, UA 3077, 3175, 3177

A3188x 80 to 200 -200 to -80 160 to 400 E/L LT, UA

A3189x 50 to 250 -250 to -50 100 to 500 E/L LT, UA 3075, 3076

A3280x 5 to 40 -40 to -5 10 to 80 E/L LH, LT, UA chopper stabilized

A3281x 15 to 90 -90 to -15 30 to 180 E/L LH, LT, UA chopper stabilized

A3283x 100 to 180 -180 to -100 <400 (Typ 300) E/L LH, LT, UA chopper stabilized

“PROTECTED” LATCHING HALL-EFFECT DIGITAL SWITCHES

Partial Operate Release Hysteresis

Part Point (G) Point (G) (G) Oper.

Number

Over Oper. Voltage & Temp. Range

Temp. Packages Comments

A3195x 40 to 200 -200 to -40 >110 (Typ 220) E, L U, LT active pulldown

A3197x 40 to 200 -200 to -40 >110 (Typ 230) E, L U, LT open-collector output

Notes: 1) Typical data is at TA = +25°C and nominal operating voltage.

2) “x” = Operating Temperature Range [suffix letter or (prefix)]: S (UGN) = -20°C to +85°C, E = -40°C to +85°C,

J = -40°C to +115°C, K (UGS) = -40°C to +125°C, L (UGL) = -40°C to +150°C.