Allegro A3134LUA, A3134LU, A3134LLT, A3134EUA, A3134EU Datasheet

Always order by complete part number, e.g., A3134ELT .

FEATURES

■ 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

This low-hysteresis bipolar Hall-effect switch is an extremely
temperature-stable and stress-resistant sensor 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 stability by
compensating for temperature changes in the Hall element. Additionally,
internal compensation provides magnetic switch points that become more
sensitive with temperature, hence offsetting the usual degradation of the
magnetic field with temperature. Its low hysteresis makes this device
ideal for detecting small changes in magnetic field strength or for use
with inexpensive magnets.

The device includes on a single silicon chip a voltage regulator,
quadratic 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 volts 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 -40°C to +150°C. Three package styles provide a magneti­cally optimized package for most applications. Suffix ‘–LT’ is a minia­ture SOT-89/TO-243AA transistor package for surface-mount applica­tions; suffix ‘–U’ is a three-lead plastic mini-SIP while suffix ‘–UA’ is a
three-lead ultra-mini-SIP.

Pinning is shown viewed from branded side.

ABSOLUTE MAXIMUM RATINGS

at TA = +25°C

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

Reverse Battery Voltage, V

RCC

.......... -30 V

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

Output OFF Voltage, V

OUT

.................. 30 V

Reverse Output Voltage, V

OUT

........... -0.5 V

Continuous Output Current,

I

OUT

............................................ 25 mA

Operating Temperature Range, T

A

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

27631.4B

3134

BIPOLAR HALL-EFFECT SWITCH

FOR HIGH-TEMPERATURE OPERATION

Dwg. PH-003A

1

SUPPLY

V

CC

GROUND

32

OUTPUT

X

3134

LOW-HYSTERESIS
BIPOLAR HALL-EFFECT SWITCH
FOR HIGH-TEMP. OPERATION

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Supply Voltage V

CC

Operating 3.8 — 24 V

Output Saturation Voltage V

OUT(SAT)

I

OUT

= 20 mA, B > B

OP

— 175 400 mV

Output Leakage Current I

OFF

V

OUT

= 24 V, B < B

RP

— 0.05 1.0 µA

Supply Current I

CC

B < BRP (Output OFF) — 3.2 9.0 mA

B > BOP (Output ON) — 5.0 — mA

Output Rise Time t

r

RL = 820 Ω, CL = 20 pF — 100 — ns

Output Fall Time t

f

RL = 820 Ω, CL = 20 pF — 100 — ns

ELECTRICAL CHARACTERISTICS over operating temperature range, at V

CC

= 12 V.

MAGNETIC CHARACTERISTICS over operating supply voltage range.

V

CC

X

REG.

Dwg. FH-005-3

GROUND

OUTPUT

1

3

2

FUNCTIONAL BLOCK DIAGRAM

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Operate Point B

OP

at TA = +25°C-408.550G

Over Oper. Temp. Range -40 – 50 G

Release Point B

RP

at TA = +25°C-50-1940G

Over Oper. Temp. Range -50 – 40 G

Hysteresis B

hys

at TA = +25°C 102750 G

Over Oper. Temp. Range 5.0 – 55 G

Copyright © 1995, 1999, Allegro MicroSystems, Inc.

NOTES: BOP = operate point (output turns ON); BRP = release point (output turns OFF); B

hys

= hysteresis (BOP - BRP).
As used here, negative flux densities are defined as less than zero (algebraic convention).
Typical values are at TA = +25°C and VCC = 12 V.

3134

LOW-HYSTERESIS

BIPOLAR HALL-EFFECT SWITCH

FOR HIGH-TEMP. OPERATION

TYPICAL OPERATING CHARACTERISTICS

0 25 50 75

100

AMBIENT TEMPERATURE IN °C

-50

Dwg. GH-053

125-25

SUPPLY CURRENT IN mA

5.0

4.0

3.0

2.0

1.0
150

V = 12 V

CC

B < B

RP

V = 24 V

CC

V = 4.5 V

CC

OUTPUT SATURATION VOLTAGE SUPPLY CURRENT

0 25 50 75

100

AMBIENT TEMPERATURE IN °C

-50

Dwg. GH-052

125-25

SWITCH POINT IN GAUSS

40

20

0

-20

-40

RELEASE POINT

OPERATE POINT

150

CC

V = 4.5 V–24 V

SWITCH POINTS HYSTERESIS

0 25 50 75

100

AMBIENT TEMPERATURE IN °C

-50

Dwg. GH-051

125-25

HYSTERESIS IN GAUSS

20

10

0

150

30

CC

V = 4.5 V–24 V

40

50

0255075

100

300

0

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

CC