General Description

    Using low power CMOS process, the AS1821B 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 AS1821B is typically less than 1.7uA at 1.8V power supply. AS1821B 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 DFN1014-4L and DFN1010-4L package is rated over the -40°C to 125°C. The all packages are RoHS and Green compliant.


●  Input Voltage Range : 1.65V to 5.0V
●  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=30Gauss BOPN= -40Gauss, BRPN= -20Gauss
●  Good RF noise immunity
●  No need pull-up resistor
●  Small Solution Size
●  RoHS & Green Compliant
●  DFN1014-4L and DFN1010-4L Packages
●  -40℃ to +125 ℃ Temperature Range


●  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









AS12XX是我司新发布的一款用于两线制(非 3 线制,只需使用 VDD 和 GND 引脚即可)垂直磁场的检测,是一款功能强大设计简易的高集成度芯片。