Diodes AH1884 User Manual

AH1884

MICROPOWER, ULTRA-SENSITIVE HALL EFFECT

SWITCH

Description

AH1884 is with two Hall effect plates and dual CMOS output driver, mainly designed for battery–operation, hand-held equipment (such as Cellular and Cordless Phone, PDA). The total operation power is down to 15uW in the 1.8V supply.

Either north or south pole of sufficient strength will turn the output on. The output will be turned off under no magnetic field. While the magnetic flux density (B) is larger than operate point (Bop), the output will be turned on (low), the output is held until B is lower than release point (Brp), then turned off.

Features

• Micropower operation

• Operation with North or South Pole

• 1.65V to 3.3V battery operation

• Chopper stabilized

• Superior temperature stability

• Extremely Low Switch-Point Drift

• Insensitive to Physical Stress

• Good RF noise immunity

• -40°C to 85°C operating temperature

• ESD ＞ 4KV in human body mode

• Package: SOT553

• “Green” Molding Compound

Pin Assignments

( Top View )

Out 2

GND

1 2

NC

Applications

• Cellular phone

• PDA

• Cordless phone

SOT553

5

Out 1

Vdd

43

Typical Application Circuit

AH1884

Document number: DS31171 Rev. 6 - 2

Vdd

AH1884

GND

Output 1

Output 2

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MICROPOWER, ULTRA-SENSITIVE HALL EFFECT

Pin Descriptions

Pin Name P/I/O Pin # Description

Out 2 O 1 Output Pin ( active High )

GND P/I 2 Ground

NC 3 No Connection

Vdd P/I 4 Power Supply Voltage

Out 1 O 5 Output Pin ( active Low )

Functional Block Diagram

Vdd

Power switch

Latch

Hall Plate

Cancelling

Offset

Amp

AH1884

SWITCH

Out1

GND

Hall Plate

Cancelling

Logical

Offset

Amp

Latch

Absolute Maximum Ratings (T

= 25°C)

A

Symbol Characteristics Values Unit

Vdd Supply voltage 5 V

B Magnetic flux density Unlimited

TS Storage Temperature Range -65 to +150 °C

PD Package Power Dissipation 230 mW

TJ Maximum Junction Temperature 150 °C

Recommended Operating Conditions (T

= 25°C)

A

Symbol Parameter Conditions Rating Unit

Vdd Supply Voltage Operating 1.65 to 3.3 V

TA Operating Temperature Range Operating -40 to +85

Vdd

Out2

GND

°C

AH1884

Document number: DS31171 Rev. 6 - 2

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September 2010

AH1884

MICROPOWER, ULTRA-SENSITIVE HALL EFFECT

SWITCH

Electrical Characteristics (TA = 25°C, Vdd = 1.8V, unless otherwise specified)

Symbol Characteristic Conditions Min Typ. Max Unit

VOH Output On Voltage (High side) IO= -0.5mA Vdd-0.2 - - V VOL Output On Voltage (Low side) IO= 0.5mA - - 0.2 V

Idd(en)

Idd(dis) Chip disable - 5 8 uA Idd(avg) average supply current - 7 12 uA Tawake Awake Time - 50 100 µs

Tperiod Period - 50 100 ms

D.C. Duty Cycle - 0.1 - %

Supply Current

Chip enable - 2 4 mA

Magnetic Characteristics (T

Symbol Characteristic Min Typ. Max Unit

Bops(south pole to brand side) Bopn(north pole to brand side) -55 -37 Brps(south pole to brand side) Brpn(north pole to brand side) - -29 -15 Bhy(|Bopx|-|Brpx|) Hysteresis 3 8 -

Notes: 1. Typical data is at Ta = 25°C, Vdd = 3V, and for design information only.

2. The magnetic characteristics may vary with supply voltage, operating temperature and after soldering.

= 25°C, Vdd = 1.8V~3.0V, Note 1 & 2)

A

Operate Point

Release Point

- 37 55

15 29 -

(1mT=10 Gauss)

Gauss

)

Voltage

Output (

Turn on

V

dd

Output1

( off-state )

hy

B

Turn off

)

Voltage

Turn off

Output (

Output1

( off-state )

B

hy

dd

V

Turn on

( on-state )

opn

B

( Magnetic flux density B )

AH1884

Document number: DS31171 Rev. 6 - 2

B

rpn

sat

V

0

V

rps

B

0

( Magnetic flux density B )

( on-state )

ops

B

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September 2010