AH1898

NEW PRODUCT AH1898 PROGRAMMABLE MICROPOWER OMNIPOLAR HALL-EFFECT SWITCH Description The AH1898 is a micropower magnetic range selectable (Bop/Brp) Omnipolar Hall effect switch IC with internal pull up and pull down capability, designed for portable and battery powered consumer equipment such as cellular phones and portable PCs. To support battery powered equipment and low voltage microcontrollers, the AH1898 can operate over the supply range of 1.6V to 3.6V and uses a hibernating clocking system to minimize the power consumption. The average supply current is only 4.3µA typical at 1.80V. The AH1898 has an 8kV ESD rating on the supply and output pins. To minimize PCB space, the AH1898 is packaged in the small CSP package (0.81mm x 0.81mm typical). Pin Assignments (Top View) BSEL A1 GND A2 (Bottom View) GND BSEL A2 A1 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 pin can be hardwired or be changed on the fly via a logic source such as a micro-controller. 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). The output will remain off when there is no magnetic field. B2 B1 B1 B2 VDD OUTPUT OUTPUT VDD U...