Allegro A3161EUA, A3161ELT Datasheet

27621.30A‡

Data Sheet

3161

HALL-EFFECT SWITCH

FOR 2-WIRE APPLICATIONS

This Hall-effect switch is a monolithic integrated circuit designed to operate continuously over extended temperatures to +85°C. The unipolar switching characteristic makes this device ideal for use with a simple bar or rod magnet. The A3161ELT and A3161EUA are identical except

for package.

Each device includes a voltage regulator for operation with supply voltages of 3.5 to 25 volts, reverse battery protection diode, quadratic Hall-voltage generator, temperature compensation circuitry, small-signal amplifier, Schmitt trigger, and a constant-current open-collector output. Noise radiation is limited by control of the output current slew rate.

Two 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 ‘UA’ is a threelead ultra-mini SIP for through-hole mounting.

SUPPLY

Pinning is shown viewed from branded side.

ABSOLUTE MAXIMUM RATINGS

at TA = +25°C

Supply Voltage, V

Continuous ................................. 28 V

Surge (tw ≤ 100 ms) .................... 40 V

Reverse Battery Voltage, V

Continuous ................................ -25 V

Surge (tw ≤ 100 ms) ................... -40 V

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

Output OFF Voltage, V

Operating Temperature Range,

TA............................. -40°C to +85°C

Storage Temperature Range,

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

GROUND

Dwg. PH-003-3

OUT

OUTPUT

RCC

.............. 28 V

FEATURES and BENEFITS

■ Internal Current Regulator for 2-Wire Operation

■ Output Slew Rate Controlled

■ 3.5 V to 25 V Operation … Needs Only An Unregulated Supply

■ Reverse Battery Protection

■ Excellent Temp. Stability

■ Activate with Small, Commercially Available Permanent Magnets

■ Small Size

■ Solid-State Reliability … No Moving Parts

■ Resistant to Physical Stress

Always order by complete part number, e.g., A3161ELT .

3161

HALL-EFFECT SWITCH FOR 2-WIRE APPLICATIONS

ELECTRICAL CHARACTERISTICS over operating voltage and temperature ranges.

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Supply Voltage V

Load Current I

OUT

+ I

(2-wire application)

Output Current I

Output Saturation Voltage V

OUT

OFF

OUT

Output Slew Rate di/dt CL = 20 pF — 7.0 20 mA/µs

Operating 3.5 — 25 V

3.5 V ≤ V

≥ 12 V, B < B

OUT

B > B

B < B

= 24 V, B > B

OUT

= 5 mA, B < B

OUT

< 12 V, B < B

OUT

12 15 17 mA

12 15 19 mA

—3.55.0 mA

—12— mA

— <1.0 10 µA

–0.91.5 V

Output Settling Time t

CL = 20 pF — — 20 µs

MAGNETIC CHARACTERISTICS over operating supply voltage range.

Limits

At TA = +25°C

Over Oper. Temp. Range

Characteristic Symbol Min. Typ. Max. Min. Typ. Max. Units

Operate Point (output turns OFF) B

Release Point (output turns ON) B

Hysteresis (BOP - BRP)B

hys

– 130 160 – 130 160 G

30 110 – 30 110 – G

5.0 20 – 5.0 20 80 G

NOTE:Typical values are at TA = +25°C and VCC = 12 V.

FUNCTIONAL BLOCK DIAGRAM

REG.

OUTPUT

GROUND

Dwg. FH-017

HALL-EFFECT SWITCH

FOR 2-WIRE APPLICATIONS

TYPICAL OPERATING CHARACTERISTICS

SWITCH POINTS TOTAL SUPPLY CURRENT

3161

200

150

OPERATE POINT

100

SWITCH POINT in GAUSS

-25 25 75 125

-50

0 50 100

AMBIENT TEMPERATURE in °C

OUTPUT SATURATION VOLTAGE SAFE OPERATING AREA

1200

RELEASE POINT

OVER OPER. VOLT. RANGE

Dwg. GH-044-1

150

VCC = 25 V

) in mA

VCC = 3.5 V

+ I

OUT

5.0

VCC = 25 V

TOTAL SUPPLY CURRENT (I

VCC = 3.5 V

-50

0 255075100

AMBIENT TEMPERATURE in °C

B < B

B > B

125-25 150

Dwg. GH-028-4

1000

800

600

400

SATURATION VOLTAGE in mV

200

-50

-25

0 25 50 75

AMBIENT TEMPERATURE in °C

www.allegromicro.com

100

OUT

= 5 mA

= 10 V

125

Dwg. GH-029-3

150

PACKAGE SUFFIX

CODE -UA

PACKAGE SUFFIX

CODE -LT

MAXIMUM CONTINUOUS SUPPLY VOLTAGE in VOLTS

40 80 120 180

20 60 100

AMBIENT TEMPERATURE in °C

140

160

Dwg. GH-068

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