Diodes AH1903 User Manual

New prod uc t ah1903, Description, Features

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AH1903

Document number: DS36568 Rev. 2 - 2

1 of 12

www.diodes.com

January 2014

© Diodes Incorporated

NEW PROD

UC

T

AH1903

HIGH SENSITIVITY MICROPOWER

UNIPOLAR/OMNIPOLAR SELECTABLE HALL-EFFECT SWITCH

Description

The AH1903 is a high sensitivity micropower Omnipolar or Unipolar
selectable Hall effect switch IC with internal pull up and pull down
capability. Designed for battery powered consumer equipment such
as cellular phones and portable PCs to office equipment, home
appliances and industrial applications, the average supply current is
only 4.3µA at 1.8V. To support portable equipment the AH1903 can
operate over the supply range of 1.6V to 3.6V and uses a hibernating
clocking system to minimize the power consumption. To minimize
PCB space the AH1903 is available in a small low profile X1-
DFN1216-4 package.

The user can change the Hall switch function between Unipolar and
Omnipolar operation via the Select (SEL) pin. If the SEL pin is open
circuit or pulled high the AH1903 operates in Unipolar switch mode
detecting only a South pole to the part mark side of the package. If
the SEL pin is pulled low the AH1903 functions as a Omnipolar switch
detecting either a North or South pole. The output is activated with a
pole of sufficient magnetic field strength. When the magnetic flux
density (B) perpendicular to the package is larger than operate point
(Bop), the output will be turned on (pulled low) and held until B is
lower than release point (Brp).

Features

Unipolar or Omnipolar Operation
ƒ

Operation can be changed by a logic source or fixed via
PCB design with no additional components

Supply Voltage of 1.6V to 3.6V

• High

Sensitivity

• Micropower

Operation

Chopper Stabilized Design Provides
ƒ

Superior Temperature Stability

ƒ

Minimal Switch Point Drift

ƒ

Enhanced Immunity to Physical Stress

No External Pull-up Resistors Required

Good RF Noise Immunity

-40°C to +85°C Operating Temperature

High ESD capability of 8kV (Human Body Model) on V

DD

, GND

and OUTPUT Pins

Small Low Profile X1-DFN1216-4 Package

Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)

Halogen and Antimony Free. “Green” Device (Note 3)

Pin Assignments



Applications

Open and Close Detect for flip/slide Cellular Phones

Smart Cover or Dock Detect for Cellular Phones and Tablet PCs

Cover or Display Switch in Portable PCs (eg Ultrabook)

Digital Still, Video Cameras and Handheld Gaming Consoles

Door, Lids and Tray Position Switches

Level, Proximity and Position Switches

Contact-Less Switches in Home Appliances and Industrial
Applications


Typical Application Circuit





Notes:

1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.

2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"

and Lead-free.

3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and

<1000ppm antimony compounds.

4.

C

IN

is for power stabilization and to strengthen the noise immunity, the recommended capacitance is 100nF typical and should be placed as close to the

supply pin as possible.

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