General Description

Using low power CMOS process, the AS1821A 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 AS1821A is
typically less than 4.0uA at 1.8V power supply. AS1821A 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 Packages and is rated over the -40°C to
85°C. The all packages are RoHS and Green
compliant.

Features

 Input Voltage Range : 1.6V to 5.5V
 Micro-power consumption ideal for battery
power applications
 Unipolar Operation, dual output
 Very high sensitivity hall sensor
 Low Power CMOS process technology
 Chopper stabilization amplifier stage
 Magnetic Sensitivity (typical)
BOPS=28Gauss, BRPS=18Gauss
BOPN= -28Gauss, BRPN= -18Gauss
 Good RF noise immunity
 No need pull-up resistor
 Small Solution Size
 RoHS & Green Compliant
 DFN1014-4L and DFN1010-4L Packages
 -40℃ to +85 ℃ 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