Diodes AH1888 User Manual

MICROPOWER, GENERAL-SENSITIVE HALL EFFECT

Description

The AH1888 micro power Omni-polar Hall Effect switch IC designed for portable and battery powered equipment such as cellular phones, PDA’ s and portable PC’ s. Based on two sensitive Hall Effect plates and chopper stabilized architecture the AH1888 provides a reliable solution over the whole operating range. To support portable and battery powered equipment the design has been optimized to operate over the supply range of 1.65V to 3.3V and consumes only 12.6µW with a supply of 1.8V.

The outputs are switched with either a north or south pole of sufficient strength. When the magnetic flux density (B) is larger than operate point (Bop) the output is switched on. The output is turned off when B becomes lower than the release point (Brp). The output will remain off when there is no magnetic field. The AH1888-ZG has two outputs, output one pulls low when switched on and output two is inverted. The AH1888-FJG provides output one and AH1888-FJRG provides output two.

Features

• Omni-polar (north or south pole) operation

• Single or dual output options

• Internal output pull up capability

• Micropower operation

• 1.65V to 3.3V operating range

• Chopper stabilized design provides

• Superior temperature stability

• Minimal switch point drift

• Enhanced immunity to stress

• Good RF noise immunity

• -40°C to 85°C operating temperature

• ESD (HBM)＞4KV for SOT553

• ESD (HBM)＞5KV for U-DFN2020-3 and U-DFN2020R-3

• Package: SOT553, U-DFN2020-3 and U-DFN2020R-3

• Halogen and Antimony free “Green” device

AH1888

Document number: DS31565 Rev. 8 - 2

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AH1888

Pin Assignments

( Top View )

5

43

(Top View)

3. GND

U-DFN2020R-3

GND

NC

1

2

SOT553

2. Output 11. Vdd

Output 2

(Top View)

3. GND

U-DFN2020-3

Applications

• Cellular phone

• Portable PC and PDAs

• Camcorders

• Cordless phone

• Contactless switch in consumer products

SWITCH

Output1

Vdd

2. Output 21. Vdd

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AH1888

Typical Application Circuit

(1) SOT553 (2) U-DFN2020-3 (3) U-DFN2020R-3

Vdd

MICROPOWER, GENERAL-SENSITIVE HALL EFFECT

SWITCH

Vdd

Output 1

AH1888

GND

Output 2

AH1888

Pin Descriptions

Pin Name P/I/O Description

Vdd P/I Power Supply Voltage

GND P/I Ground Output 1 O Output Pin ( Active Low ) Output 2 O Output Pin ( Active High )

AH1888

Document number: DS31565 Rev. 8 - 2

Output 1

GND

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AH1888

GND

Output 2

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Functional Block Diagram

(1) SOT553

Hall

Plate

Cancellation

Offset

AH1888

MICROPOWER, GENERAL-SENSITIVE HALL EFFECT

SWITCH

Vdd

Sleep/Awake Logic

and Power Switch

Amp

Latch

Output 1

(2) U-DFN2020-3

(3) U-DFN2020R-3

Hall

Plate

Hall

Plate

Hall

Plate

Cancellation

Offset

Cancellation

Offset

Amp

Latch

Vdd

Sleep/Awake Logic

and Power Switch

Latch

Vdd

Output

Controller

Output

Driver

Controller

Driver

GND

Vdd

Output 2

GND

Output 1

GND

Hall

Plate

Hall

Plate

AH1888

Document number: DS31565 Rev. 8 - 2

Cancellation

Offset

Amp

Sleep/Awake Logic

and Power Switch

Latch

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Output

Driver

Controller

Output 2

GND

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AH1888

Absolute Maximum Ratings (T

Symbol Characteristics Values Unit

Vdd Supply voltage 5 V

B Magnetic flux density Unlimited TS PD TJ

Recommended Operating Conditions (T

Symbol Characteristic Conditions Rating Unit

Vdd Supply Voltage Operating 1.65 to 3.3 V

TA

Electrical Characteristics (T

Symbol Characteristic Conditions Min Typ. Max Unit

VOH VOL

Idd(en)

Idd(dis) Chip disable - 5 8 µA

Idd(avg) Average supply current - 7 12 µA

Tawake Awake Time (Note 1) - 50 100 µs Tperiod Period (Note 1) - 50 100 ms

D.C. Duty Cycle - 0.1 - %

Notes: 1. When power is initially turned on, Vdd must be within its correct operating range (1.65V to 3.3V) to guarantee the output sampling. The output state is

valid after the second operating cycle (typical 100ms).

AH1888

Document number: DS31565 Rev. 8 - 2

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

Operating Temperature Range Operating -40 to +85 °C

= 25°C, Vdd = 1.8V, unless otherwise specified)

A

Output On Voltage (High side) Output On Voltage (Low side)

Supply Current

MICROPOWER, GENERAL-SENSITIVE HALL EFFECT

= 25°C)

A

= 25°C)

A

IO = -0.5mA IO = 0.5mA Chip enable - 2 4 mA

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Vdd - 0.2 - - V

- - 0.2 V

SWITCH

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