Diodes, Inc. Distributor

AH1898 Programmable, Omnipolar Switch


Diodes programmable micropower omnipolar hall-effect switch


Diodes' AH1898 Programmable, Omnipolar SwitchDiodes Incorporated introduces a programmable omnipolar hall-effect switch, enabling designers to use the same contactless detection circuit in multiple applications or with different field strengths. The miniature and micropower AH1898 is suitable for numerous portable consumer applications including cell phones, tablets and cameras as well as a variety of domestic, office and industrial equipment. Able to detect both north and south magnetic fields, the AH1898 features a band-select pin, which allows device sensitivity to be changed to one of two predefined magnetic sensitivity ranges. In addition, it can also be used to change the band on the fly, using an external logic source or microcontroller. The high sensitivity of the hall sensor also means that it can support weaker, lower cost magnets and can be used at a greater distance from the magnet.

The AH1898 Hall switch has been optimized for use over a 1.6 V to 3.6 V low-voltage supply range and employs a hibernating clocking system to minimize power consumption. With an average supply current of just 4.3 μA (typical) at 1.8 V, this micropower device helps to extend portable battery cell lifetime. To ensure high reliability in a broad range of applications, the AH1898 has been designed with an 8 kV ESD rating on supply and output pins. Circuit robustness is further raised by the AH1898’s chopper stabilized design, delivering superior temperature stability over the operating range from -40ºC to +85ºC, absolute minimum switch point drift, and enhanced immunity to RF noise and physical stress.

The AH1898 is available in the miniature 0.8 mm x 0.8 mm CSP package, making it 12 times smaller than common TSOT-packaged alternatives. At the same time, its simple 4-pin footprint and integration of pull-up resistors result in reduced external component counts and a simplification of PCB layouts.

Features
  • Omnipolar operation (north or south pole)
  • Supply voltage of 1.6 V to 3.6 V
  • Micropower operation
  • Chopper stabilized design provides
    • Superior temperature stability
    • Minimal switch point drift
    • Enhanced immunity to physical stress
  • Programmable operate and release points
  • No external pull-up resistors required
  • Good RF noise immunity
  • -40°C to +85°C operating temperature
  • 8 kV human body model ESD capability
  • Miniature U-WLB0808-4 (CSP 0.81 mm x 0.81 mm typical)

Applications
  • Open and close detect for cellular phones
  • Cover or display switch in portable PCs
  • Holster or cover detect for cellular phones and tablet PCs
  • Proximity and position switches
  • Digital still video cameras and handheld gaming consoles

Digi-Key P/N Manufacturer P/N Description
AH1898-CA4-7DICT-ND AH1898-CA4-7 IC HALL SENSR OMNI SW UWLB0808-4 Datasheet
Available in Tape & Reel (TR-ND), Cut Tape (CT-ND), and custom Digi-Reel® (DKR-ND)