Diodes AH1894 - Manual

AH1894
Document number: DS35741 Rev. 1 - 2
1 of 13
www.diodes.com
July 2013
© Diodes Incorporated
NEW PROD
UC
T
AH1894
PROGRAMMABLE HIGH SENSITIVITY
MICROPOWER OMNIPOLAR HALL-EFFECT SWITCH
Description
The AH1894 is a high sensitivity micropower magnetic range
selectable Omnipolar Hall effect switch IC with internal pull up and
pull down capability. Designed for portable and battery powered
equipment such as cellular phones and portable PCs to home
appliances and industrial applications, the average power
consumption is only 8uW at 1.85V. To support portable equipment the
AH1894 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 AH1894 is available in small low profile
X1-DFN1216-4 and SOT553 packages.
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) 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
 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
 High ESD capability of 8kV (Human Body Model) on V
DD
, GND
and OUTPUT Pins

Small Low Profile X1-DFN1216-4 and SOT553 Packages
 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)

Halogen and Antimony Free. “Green” Device (Note 3)
Pin Assignments
(Top View)
X1-DFN1216-4
(Top View)
SOT553
Applications

Open and Close Detect for Cellular Phones

Holster or cover detect for cellular phones and Tablet PCs
 Cover or Display Switches in Portable PCs
 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
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.
Typical Applications Circuit
Note: 4. C
IN
is for power stabilization and to strengthen the noise immunity, the recommended capacitance is 100nF typical.