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 magnetic field direction with 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).
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
Features
• Unipolar or Omnipolar Operation
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
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 VDD, 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)
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. CIN 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.
AH1903
Document number: DS36568 Rev. 3 - 2
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www.diodes.com
June 2014
© Diodes Incorporated
