A1143ELH - Allegro MicroSystems, Inc.

A1140/41/42/43

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

AB SO LUTE MAX I MUM RAT INGS

Supply Voltage, VCC ..........................................28 V

Reverse-Supply Voltage, VRCC ........................–18 V

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

Power Dissipation, PD............................ Graph, p. 5

Operating Temperature

Ambient, TA, Range E.................. –40ºC to 85ºC

Ambient, TA, Range L................ –40ºC to 150ºC

Maximum Junction, TJ(max)........................165ºC

Storage Temperature, TS.................. –65ºC to 170ºC

On-chip protection

 Supply transient protection

 Reverse-battery protection

 On-board voltage regulator

 3.5 to 24 V operation

Sensitive Two-Wire Chopper-Stabilized

Unipolar Hall Effect Switches

Package LH, 3-pin SOT

Features and Benefits

The A1140, A1141, A1142, and A1143 devices are sensitive, two-wire, unipolar,

Hall effect switches that are factory-programmed at end-of-line to optimize mag-

netic switchpoint accuracy. These devices use a patented high frequency chop-

per-stabilization technique, produced using the Allegro advanced BiCMOS wafer

fabrication process, to achieve magnetic stability and to eliminate offset inherent

in single-element devices exposed to harsh application environments.

Commonly found in a number of automotive applications, these switches are

utilized to sense seat track position, seat belt buckle presence, hood/trunk latching,

and shift selector position. Two-wire unipolar switches, such as the

A1140/41/42/43 family, are particularly advantageous in price-sensitive applica-

tions because they require one less wire for operation than do switches with the

more traditional open-collector output. Additionally, the system designer inher-

ently gains diagnostics because there is always output current flowing, which

should be in either of two narrow ranges. Any current level not within these ranges

indicates a fault condition. The A1140/41/42/43 family of switches also features

on-chip transient protection and a Zener clamp to protect against overvoltage

conditions on the supply line.

The output currents of the A1141 and A1143 switch HIGH in the presence of a

south (+) polarity magnetic field of sufficient strength, and switch LOW other-

wise, as in the presence of a weak field or a north (–) polarity field. The other two

devices in the family (A1140 and A1142) have an opposite output: the currents

switch LOW in the presence of a south-polarity magnetic field of sufficient

strength, and switch HIGH otherwise. The other differences in the switches are

their defined low current levels and magnetic switchpoints.

All versions are offered in two package styles. The LH is a SOT-23W, miniature

low-profile package for surface-mount applications. The UA is a three-lead ultra-

mini SIP for through-hole mounting. Each package is available in a lead (Pb) free

version (suffix, –T) with 100% matte tin plated leadframe. Field-programmable

versions also available: A1180, A1181, A1182, and A1183.

Package UA, 3-pin SIP

Chopper stabilization

 Low switchpoint drift over operating

temperature range

 Low sensitivity to stress

Factory programmed at end-of-line for

optimized switchpoints

≈1:1

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Functional Block Diagram

Amp

Regulator

Low-Pass

Filter

GND

VCC

GND

Package UA Only

0.01 uF

V+

Clock/Logic

Dynamic Offset

Cancellation

Sample and Hold

To All Subcircuits

1. VCC

2. No connection

3. GND

PTCT

1 2 3

1. VCC

2. GND

3. GND

Package LH, 3-pin SOT Package UA, 3-pin SIP

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

ELECTRICAL CHARACTERISTICS over the operating voltage and temperature ranges, unless otherwise specified

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Supply Voltage1VCC 3.5 – 24 V

Supply Current

ICC(L)

B>BOP for A1140; B<BRP for A1141 2 – 5 mA

B>BOP for A1142; B<BRP for A1143 5 -– 6.9 mA

ICC(H)

B>BOP for A1141, A1143

B<BRP for A1140, A1142 12 -– 17 mA

Reverse Supply Current IRCC VCC = –18 V – – –1.2 mA

Supply Zener Clamp Voltage VZSUPPLY ICC = ICCL(max) + 3 mA; TA = 25°C 28 – 40 V

Supply Zener Clamp Cur-

rent3IZSUPPLY VZSUPPLY = 28 V – – 10 mA

Output Slew Rate4di/dt Capacitance of the oscilloscope performing the

measurement = 20 pF – 36 – mA/µs

Chopping Frequency fC– 200 – kHz

Power-On Time5ton CBYPASS = 0.01 µF – – 25 µs

Power-On State6,7 POS t < ton; VCC slew rate > 25 mV/µs – HIGH – –

MAGNETIC CHARACTERISTICS over the operating voltage and temperature ranges, unless otherwise specified

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

Operate Point BOP

A1440, A1442 ICC = ICCL 50 80 115 G

A1441, A1443 ICC = ICCH

Release Point BRP

A1440, A1442 ICC = ICCH 45 65 110 G

A1441, A1443 ICC = ICCL

Hysteresis BHYS BHYS = BOP – BRP 51530G

*Typical data taken at TA = 25°

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Characteristic Data

Supply Current (Low) versus Ambient Temperature

at Various Levels of VCC

(A1142 and A1143)

Supply Current (Low) versus Ambient Temperature

at Various Levels of VCC

(A1140 and A1141)

Ambient Temperature, TA(°C)

VCC

3.5 V

12.0 V

24.0 V

VCC

3.5 V

12.0 V

24.0 V

ICCL (mA)

4 4

–50 0 50 100 150 200 –50 0 50 100 150 200

–50 0 50 100 150 200

Operate Point versus Ambient Temperature

at Various Levels of VCC

(A1140, A1141, A1142, and A1143)

Supply Current (High) versus Ambient Temperature

at Various Levels of VCC

(A1140, A1141, A1142, and A1143)

Ambient Temperature, TA(°C)

VCC

3.5 V

12.0 V

24.0 V

VCC

3.5 V

12.0 V

24.0 V

ICCH (mA)

BOP (G)

–50 0 50 100 150 200

Switchpoint Hysteresis versus Ambient Temperature

at Various Levels of VCC

(A1140, A1141, A1142, and A1143)

Ambient Temperature, TA(°C)

VCC

3.5 V

12.0 V

24.0 V

BHYS (G)

–50 0 50 100 150 200

110

100

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information

Characteristic Symbol Test Conditions Value Units

Package Thermal Resistance RθJA

Package LH, minimum-K PCB (single layer, single-sided with

copper limited to solder pads) 110 ºC/W

Package LH, low-K PCB (single layer, double-sided with

0.926 in2 copper area) 228 ºC/W

Package UA, minimum-K PCB (single layer, single-sided with

copper limited to solder pads) 165 ºC/W

20 40 60 80 100 120 140 160 180

Maximum Allowable V

(V)

J(max)

= 165ºC; I

CC(max)

Power Derating Curve

θJA

= 228 ºC/W)

Minimum-K PCB, Package LH

θJA

= 110 ºC/W)

Low-K PCB, Package LH

θJA

= 165 ºC/W)

Minimum-K PCB, Package UA

VCC(min)

VCC(max)

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

20 40 60 80 100 120 140 160 180

Temperature (°C)

Power Dissipation, P

(mW)

Power Dissipation versus Ambient Temperature

(RθJA =165ºC/W)

Minimum-K PCB, PackageUA

(RθJA =228ºC/W)

Minimum-K PCB, Package LH

(RθJA = 110 ºC/W)

Low-K PCB, Package LH

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Functional Description

BOP

BRP

BHYS

ICC(H)

ICC

ICC(L)

Switch to Low

Switch to High

B+

B–

I+

(A) A1140, A1142

BOP

BRP

BHYS

ICC(H)

ICC

ICC(L)

Switch to High

Switch to Low

B+

I+

B–

(B) A1141, A1143

Operation

The output, ICC, of the A1140 and A1142 devices switch low

after the magnetic field at the Hall sensor exceeds the operate

point threshold, BOP. When the magnetic field is reduced to

below the release point threshold, BRP, the device output goes

high. The differences between the magnetic operate and release

point is called the hysteresis of the device, BHYS. This built-

in hysteresis allows clean switching of the output even in the

presence of external mechanical vibration and electrical noise.

The A1141 and A1143 devices switch with opposite polarity for

similar BOP and BRP values, in comparison to the A1140 and

A1142 (see figure 1).

Figure 1. Alternative switching behaviors are available in the A114x device family. On the horizontal axis, the B+ direction indicates

increasing south polarity magnetic field strength, and the B– direction indicates decreasing south polarity field strength (including the

case of increasing north polarity).

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Chopper Stabilization Technique

When using Hall-effect technology, a limiting factor for

switchpoint accuracy is the small signal voltage developed

across the Hall element. This voltage is disproportionally small

relative to the offset that can be produced at the output of the

Hall sensor. This makes it difficult to process the signal while

maintaining an accurate, reliable output over the specified oper-

ating temperature and voltage ranges.

Chopper stabilization is a unique approach used to minimize

Hall offset on the chip. The patented Allegro technique, namely

Dynamic Quadrature Offset Cancellation, removes key sources

of the output drift induced by thermal and mechanical stresses.

This offset reduction technique is based on a signal modulation-

demodulation process. The undesired offset signal is separated

from the magnetic field-induced signal in the frequency domain,

through modulation. The subsequent demodulation acts as a

modulation process for the offset, causing the magnetic field-

induced signal to recover its original spectrum at baseband, while

the dc offset becomes a high-frequency signal. The magnetic-

sourced signal then can pass through a low-pass filter, while the

modulated dc offset is suppressed. This configuration is illus-

trated in figure 2.

The chopper stabilization technique uses a 200 kHz high

frequency clock. For demodulation process, a sample and hold

technique is used, where the sampling is performed at twice the

chopper frequency (400 kHz). This high-frequency operation

allows a greater sampling rate, which results in higher accuracy

and faster signal-processing capability. This approach desensi-

tizes the chip to the effects of thermal and mechanical stresses,

and produces devices that have extremely stable quiescent Hall

output voltages and precise recoverability after temperature

cycling. This technique is made possible through the use of a

BiCMOS process, which allows the use of low-offset, low-noise

amplifiers in combination with high-density logic integration

and sample-and-hold circuits.

The repeatability of magnetic field-induced switching is affected

slightly by a chopper technique. However, the Allegro high-

frequency chopping approach minimizes the affect of jitter and

makes it imperceptible in most applications. Applications that

are more likely to be sensitive to such degradation are those

requiring precise sensing of alternating magnetic fields; for

example, speed sensing of ring-magnet targets. For such applica-

tions, Allegro recommends its digital sensor families with lower

sensitivity to jitter. For more information on those devices,

contact your Allegro sales representative.

Figure 2. Chopper stabilization circuit (Dynamic Quadrature Offset Cancellation)

Amp

Regulator

Clock/Logic

Hall Element

Sample and

Hold

Low-Pass

Filter

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Application Information

For additional general application information, visit the Allegro

Web site at www. allegromicro.com.

GND

A114x

VCC

V+

0.01 µF

GND

ECU

Package UA Only

BMaximum separation 5 mm

RSENSE

CBYP

Figure 3. Typical application circuit

Typical Application Circuit

The A114x family of devices must be protected by an external

bypass capacitor, CBYP, connected between the supply, VCC,

and the ground, GND, of the device. CBYP reduces both external

noise and the noise generated by the chopper-stabilization func-

tion. As shown in figure 3, a 0.01 µF capacitor is typical.

Installation of CBYP must ensure that the traces that connect it to

the A114x pins are no greater than 5 mm in length.

All high-frequency interferences conducted along the supply

lines are passed directly to the load through CBYP, and it serves

only to protect the A114x internal circuitry. As a result, the load

ECU (electronic control unit) must have sufficient protection,

other than CBYP, installed in parallel with the A114x.

A series resistor on the supply side, RS (not shown), in combina-

tion with CBYP, creates a filter for EMI pulses.

When determining the minimum VCC requirement of the A114x

device, the voltage drops across RS and the ECU sense resistor,

RSENSE, must be taken into consideration. The typical value for

RSENSE is approximately 100 Ω.

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Power Derating

The device must be operated below the maximum junction

temperature of the device, TJ(max). Under certain combinations of

peak conditions, reliable operation may require derating sup-

plied power or improving the heat dissipation properties of the

application. This section presents a procedure for correlating

factors affecting operating TJ. (Thermal data is also available on

the Allegro MicroSystems Web site.)

The Package Thermal Resistance, RθJA, is a figure of merit sum-

marizing the ability of the application and the device to dissipate

heat from the junction (die), through all paths to the ambient air.

Its primary component is the Effective Thermal Conductivity,

K, of the printed circuit board, including adjacent devices and

traces. Radiation from the die through the device case, RθJC, is

relatively small component of RθJA. Ambient air temperature,

TA, and air motion are significant external factors, damped by

overmolding.

The effect of varying power levels (Power Dissipation, PD), can

be estimated. The following formulas represent the fundamental

relationships used to estimate TJ, at PD.

PD = VIN × IIN (1)

∆T = PD × RθJA (2)

TJ = TA + ∆T (3)

For example, given common conditions such as: TA= 25°C,

VCC = 12 V, ICC = 4 mA, and RθJA = 140 °C/W, then:

D = VCC × ICC = 12 V × 4 mA = 48 mW

∆T = PD × RθJA = 48 mW × 140 °C/W = 7°C

J = TA + ∆T = 25°C + 7°C = 32°C

A worst-case estimate, PD(max), represents the maximum allow-

able power level (VCC(max), ICC(max)), without exceeding TJ(max),

at a selected RθJA and TA.

Example: Reliability for VCC at TA =

150°C, package UA, using

minimum-K PCB.

Observe the worst-case ratings for the device, specifically:

RθJA

165°C/W, TJ(max) =

165°C, VCC(max)

= 24 V, and

ICC(max) = 17 mA.

Calculate the maximum allowable power level, PD(max). First,

invert equation 3:

∆Tmax = TJ(max) – TA = 165

°C

–

150

°C = 15

°C

This provides the allowable increase to TJ resulting from internal

power dissipation. Then, invert equation 2:

PD(max) = ∆Tmax ÷ RθJA = 15°C ÷ 165 °C/W = 91 mW

Finally, invert equation 1 with respect to voltage:

VCC(est) = PD(max) ÷ ICC(max) = 91 mW ÷ 17 mA = 5 V

The result indicates that, at TA, the application and device can

dissipate adequate amounts of heat at voltages ≤VCC(est).

Compare VCC(est) to VCC(max). If VCC(est) ≤ VCC(max), then reli-

able operation between VCC(est) and VCC(max) requires enhanced

RθJA. If VCC(est) ≥ VCC(max), then operation between VCC(est) and

VCC(max) is reliable under these conditions.

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Device Qualification Program

EMC (Electromagnetic Compatibility) Requirements

Test Name Reference Specification

ESD – Human Body Model AEC-Q100-002

ESD – Machine Model AEC-Q100-003

Conducted Transients ISO 7637-1

Direct RF Injection ISO 11452-7

Bulk Current Injection ISO 11452-4

TEM Cell ISO 11452-3

Contact Allegro for information.

Contact your local representative for EMC results.

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Product Selection Guide

Use the complete part numbers when ordering

Continued on the next page....

Part Number Pb-Free PackingaPackage

Operating Ambient

Temperature, TA

(°C)

Output Level in

South (+) Fieldb

Supply Current at

Low Output, ICC(L)

(mA)

A1140ELHLT – Tape and Reel, 3000 pieces/reel Surface Mount

–40 to 85

Low

2 to 5

A1140ELHLT-T Yes

A1140EUA – Bulk Bag, 500 pieces/bag

Through Hole

A1140EUA-T Yes

A1140EUATI – Tape and Reel, 2000 pieces/reel

A1140EUATI-T Yes

A1140LLHLT – Tape and Reel, 3000 pieces/reel Surface Mount

–40 to 150

A1140LLHLT-T Yes

A1140LUA – Bulk Bag, 500 pieces/bag

Through Hole

A1140LUA-T Yes

A1140LUATI – Tape and Reel, 2000 pieces/reel

A1140LUATI-T Yes

A1141ELHLT – Tape and Reel, 3000 pieces/reel Surface Mount

–40 to 85

High

A1141ELHLT-T Yes

A1141EUA – Bulk Bag, 500 pieces/bag

Through Hole

A1141EUA-T Yes

A1141EUATI – Tape and Reel, 2000 pieces/reel

A1141EUATI-T Yes

A1141LLHLT – Tape and Reel, 3000 pieces/reel Surface Mount

–40 to 150

A1141LLHLT-T Yes

A1141LUA – Bulk Bag, 500 pieces/bag

Through Hole

A1141LUA-T Yes

A1141LUATI – Tape and Reel, 2000 pieces/reel

A1141LUATI-T Yes

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Continued from the previous page....

Part Number Pb-Free PackingaPackage

Operating Ambient

Temperature, TA

(°C)

Output Level in

South (+) Fieldb

Supply Current at

Low Output, ICC(L)

(mA)

A1142ELHLT – Tape and Reel, 3000 pieces/reel Surface Mount

–40 to 85

Low

5 to 6.9

A1142ELHLT-T Yes

A1142EUA – Bulk Bag, 500 pieces/bag

Through Hole

A1142EUA-T Yes

A1142EUATI – Tape and Reel, 2000 pieces/reel

A1142EUATI-T Yes

A1142LLHLT – Tape and Reel, 3000 pieces/reel Surface Mount

–40 to 150

A1142LLHLT-T Yes

A1142LUA – Bulk Bag, 500 pieces/bag

Through Hole

A1142LUA-T Yes

A1142LUATI – Tape and Reel, 2000 pieces/reel

A1142LUATI-T Yes

A1143ELHLT – Tape and Reel, 3000 pieces/reel Surface Mount

–40 to 85

High

A1143ELHLT-T Yes

A1143EUA – Bulk Bag, 500 pieces/bag

Through Hole

A1143EUA-T Yes

A1143EUATI – Tape and Reel, 2000 pieces/reel

A1143EUATI-T Yes

A1143LLHLT – Tape and Reel, 3000 pieces/reel Surface Mount

–40 to 150

A1143LLHLT-T Yes

A1143LUA – Bulk Bag, 500 pieces/bag

Through Hole

A1143LUA-T Yes

A1143LUATI – Tape and Reel, 2000 pieces/reel

A1143LUATI-T Yes

aContact Allegro for additional packing options.

bSouth (+) magnetic fields must be of sufficient strength.

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

Package LH, 3-Pin; (SOT-23W)

2.40

BSC

.094

1.00

BSC

.039

0.70

BSC

.028

3.10

2.90

.122

.114

2.10

1.85

.083

.073

3.00

2.70

.118

.106

0.55

REF

.022

1.49

NOM

.059

0.28

NOM

.011

0.96

NOM

.038

0.95

BSC

.037

0.95

BSC

.037

0.25

MIN

.010

0.15

0.00

.006

.000

1.13

0.87

.045

.034

0.20

0.13

.008

.005

8º

0º

0.50 .020

.012

0.30

0.25

BSC

.010

Gauge Plane

Seating Plane

Dimensions in millimeters

U.S. Customary dimensions (in.) in brackets, for reference only

AHall element

BActive Area Depth 0.28 [.011]

Fits SC–59A Solder Pad Layout

Package UA, 3-Pin SIP

.164

.159

4.17

4.04

.122

.117

3.10

2.97

.062

.058

1.57

1.47

.017

.014

0.44

0.35

.019

.014

0.48

0.36

.640

.600

16.26

15.24

.085

MAX

2.16

.050

BSC

1.27

.031

REF

0.79

.0195

NOM

0.50

.0805

NOM

2.04

1.44

.0565

NOM

45°

BSC

45°

BSC

Dimensions in inches

Metric dimensions (mm) in brackets, for reference only

231

Dambar removal protrusion

Hall element

A1140-DS, Rev. 2 Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches

A1140/41/42/43

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 de par tures from the detail spec i fi ca tions as may be

required to permit improvements in the per for mance, reliability, or

manufacturability of its products. Before placing an order, the user

is cautioned to verify that the information being relied upon is cur-

rent.

Allegro products are not authorized for use as critical compo-

nents in life-support devices or sys tems without express written

approval.

The in for ma tion in clud ed herein is believed to be ac cu rate and

reliable. How ev er, Allegro MicroSystems, Inc. assumes no re spon -

si bil i ty for its use; nor for any in fringe ment of patents or other

rights of third parties which may result from its use.