Diodes AH1894 User Manual
New prod uc t ah1894, Description, Features

AH1894
Document number: DS35741 Rev. 1 - 2
1 of 13
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. S
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.