AH1889 Unipolar Hall Effect Switch IC Diodes AH1889 is a high sensitivity dual output Unipolar Hall effect IC that can detect either a North or South pole independently and switch one of its two outputs with internal pull-up and pull-down capability. The AH1889 is mainly designed for low voltage applications that require a quick response time and can operate over the supply voltage of 1.65V to 3.6V. To minimize PCB space AH1889 outputs have internal pull up and pull down capability and is packaged in a small low profile SOT553 package. A South pole of sufficient strength will turn OUTPUT1 on and a North pole of sufficient strength with turn on OUTPUT2. While the magnetic flux density (B) perpendicular to the package is larger than operate point Bops or Bopn, the appropriate output will be turned on (pulled low), the output is held until B is lower than the release point Brps or Brps, then turned off (high). The outputs will be turned off and will remain off when there is no magnetic field.