General Description

    Using low power CMOS process, the AS1821S is designed for low power, high performance unipolar detection dual output hall-effect application, such as cover switch, contactless switch, solid state switch and lid close sensor etc battery operation. The hall IC integrated an on-chip hall voltage generator for magnetic sensing, a comparator that amplifiers the hall voltage, a chopper amplifier, a Schmitt trigger to provide switching hysteresis for noise rejection, and two complementary output.
    The total power consumption of AS1821S is typically less than 3.0uA at 3.6V power supply. AS1821S is designed to respond to alternating North and South poles. White the magnetic flux density (B) is larger than operate point (BOP), the output will be turned on (low), the output is held until the magnetic flux density (B) is lower than release point (BRP), then turn off (high).
    The device is available in SOT23-5L package is rated over the -40°C to 125°C. The all packages are RoHS and Green compliant.

Features

●  Input Voltage Range : 2.2V to 5.5V

●  Micro-power consumption ideal for battery power applications

●  Uniplar Operation, dual output

●  Very high sensitivity hall sensor
●  Low Power CMOS process technology
●  Chopper stabilization amplifier stage

●  Magnetic Sensitivity (typical) BOPS=40Gauss, BRPS=20GaussBOPN= -40Gauss, BRPN= -20Gauss

●  Good RF noise immunity
●  No need pull-up resistor
●  Small Solution Size

●  RoHS & Green Compliant

●  SOT23-5L Packages

●  -40℃ to +125 ℃ Temperature Range

Applications

●  Cover switch in clam-shell cellular phones
●  Cover switch in Notebook, PC/PAD
●  Contact-less switch in consumer products
●  Solid State Switch
●  Handheld Wireless Handset Awake Switch
●  Lid close sensor for battery-powered devise
●  Magnet proximity sensor for reed switch replacement in low duty cycle applications
●  DV, DSC, and White Goods