Diodes AH1898 - Manual

AH1898
Document number: DS36028 Rev. 1 - 2
1 of 11
www.diodes.com
February 2013
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AH1898
PROGRAMMABLE MICROPOWER OMNIPOLAR HALL-EFFECT SWITCH
Description
The AH1898 is a micropower magnetic range selectable (Bop/Brp)
Omnipolar Hall effect switch IC with internal pull up and pull down
capability, designed for portable and battery powered consumer
equipment such as cellular phones and portable PCs. To support
battery powered equipment and low voltage microcontrollers, the
AH1898 can operate over the supply range of 1.6V to 3.6V and uses
a hibernating clocking system to minimize the power consumption.
The average supply current is only 4.3µA typical at 1.80V. The
AH1898 has an 8kV ESD rating on the supply and output pins. To
minimize PCB space the AH1898 is packaged in the small
CSP package (0.81mm x 0.81mm typical).
The output is activated with either a north or south pole of sufficient
magnetic field strength. The user can select one of two magnetic
sensitivity bands via the BSEL pin without the addition of any external
components allowing a flexible but small solution. The band select
can be hardwired or be changed on the fly via a logic source such as
a micro-controller. 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). The output will remain off when there is no magnetic field.
Features
 Omnipolar Operation (North or South pole)
 Programmable Operate and Release Points
 Supply Voltage of 1.6V to 3.6V
 Micropower Operation
 Chopper Stabilized Design Provides

Superior Temperature Stability
 Minimal Switch Point Drift
 Enhanced Immunity to Physical Stress
 No External Pull-up Resistors Required
 Good RF Noise Immunity
 -40°C to +85°C Operating Temperature
 8kV Human Body Model ESD Capability
 Miniature U-WLB0808-4 (CSP 0.81mm x 0.81mm typical)
 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
 Halogen and Antimony Free. “Green” Device (Note 3)
Pin Assignments
(Top View) (Bottom View)
U-WLB0808-4
Applications
 Open and Close Detect for Cellular Phones
 Holster or Cover Detect for Cellular Phones and Tablet PCs
 Cover or Display Switch in Portable PCs
 Digital Still, Video Cameras and Handheld Gaming Consoles
 Proximity and Position Switches
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 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.