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 package is
rated over the -40°C to 125°C. The all packages are
RoHS and Green compliant.

Features

 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= -30Gauss
 Good RF noise immunity
 No need pull-up resistor
 Small Solution Size
 RoHS & Green Compliant
 DFN1014-4L 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