Diodes AH1887 User Manual

AH1887

MICROPOWER, ULTRA-SENSITIVE HALL EFFECT

SWITCH

Description

AH1887 is with two Hall effect plates and dual CMOS output driver, mainly designed for battery–powered, 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(s), the output1 will be turned on (low), the output is held until B is lower than release point Brp(s), then turned off (high).

While the magnetic flux density (B) is larger than operate point Bop(n), the output2 will be turned on (low), the output is held until B is lower than release point Brp(n), then turned off (high).

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

AH1887

Document number: DS31313 Rev. 4 - 2

Vdd

AH1887

GND

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Output 1

Output 2

August 2010

MICROPOWER, ULTRA-SENSITIVE HALL EFFECT

Pin Descriptions

Pin Name P/I/O Pin # Description

Out 2

(Note 1)

GND P/I 2 Ground

NC 3 No Connection

Vdd P/I 4 Power Supply Voltage

Out 1

(Note 1)

Notes: 1. Output1 responds to South pole; Output2 responds to North pole.

Functional Block Diagram

O 1 Output Pin ( active Low )

O 5 Output Pin ( active Low )

Vdd

AH1887

SWITCH

Power switch

Latch

Logical

GND

Vdd

Hall Plate

Cancelling

Offset

Amp

Cancelling

Offset

Amp

Absolute Maximum Ratings (T

= 25°C)

A

Symbol Characteristics Values Unit

Vdd Supply voltage 5 V

B Magnetic flux density Unlimited TS PD

Storage Temperature Range -65 to +150 °C Package Power Dissipation 230 mW

TJ Maximum Junction Temperature 150 °C

Out1

Out2

GND

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

AH1887

Document number: DS31313 Rev. 4 - 2

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°C

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AH1887

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) -50 -35 Brps(south pole to brand side) Brpn(north pole to brand side) - -20 -6 Bhy(|Bopx|-|Brpx|) Hysteresis 3 15 -

Notes: 2. Typical data is at Ta = 25°C, Vdd = 3V, and for design information only.

3. Bops & Brps for Output 1 responds to South pole; Bopn & Brpn for Output 2 responds to North pole.

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

= 25°C, Vdd = 1.8V~3.0V, Note 2, 3, 4)

A

Operate Point

Release Point

- 35 50

6 20 -

V

dd

Output2

( off-state )

Output1

( off-state )

V

(1mT=10 Gauss)

Gauss

dd

Turn on

( Output Voltage )

( on-state )

opn

B

( Magnetic flux density B )

AH1887

Document number: DS31313 Rev. 4 - 2

B

hy

B

rpn

Turn off

V

0

sat

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hy

Turn off

B

( Output Voltage )

sat

V

rps

B

NNS

0

( on-state )

ops

B

( Magnetic flux density B )

Turn on

S

August 2010