A1220, A1221, and A1222
Chopper Stabilized Precision Hall Effect Latches
Features and Benefits
Description
▪ Symmetrical latch switchpoints
▪ Resistant to physical stress
▪ Superior temperature stability
▪ Output short-circuit protection
▪ Operation from unregulated supply down to 3 V
▪ Reverse battery protection
The A1220, A1221, and A1222 Hall-effect sensor ICs are
extremely temperature-stable and stress-resistant devices
especiallysuitedforoperationoverextendedtemperatureranges
to 150°C. Superior high-temperature performance is made
possiblethroughdynamicoffsetcancellation,whichreducesthe
residualoffsetvoltagenormallycausedbydeviceovermolding,
temperature dependencies, and thermal stress. Each device
includesonasinglesiliconchipavoltageregulator,Hall-voltage
generator,small-signalamplifier,chopperstabilization,Schmitt
trigger, and a short-circuit protected open-collector output to
sink up to 25 mA. A south pole of sufficient strength turns the
output on. A north pole of sufficient strength is necessary to
turn the output off.
▪ Solid-state reliability
▪ Small package sizes
Packages:
An onboard regulator permits operation with supply voltages
of 3 to 24 V. The advantage of operating down to 3 V is that
the device can be used in 3-V applications or with additional
external resistance in series with the supply pin for greater
protection against high voltage transient events.
Two package styles provide magnetically optimized packages
for most applications. Package type LH is a modified 3-pin
SOT23WsurfacemountpackagewhileUAisathree-pinultra-
mini SIP for through hole mounting. Both packages are lead
(Pb) free, with 100% matte tin plated leadframes.
3-pin SOT23W (suffix LH)
3-pin SIP (suffix UA)
Not to scale
Functional Block Diagram
VCC
Regulator
To All Subcircuits
VOUT
Low-Pass
Filter
Amp
Control
Current Limit
GND
A1220-DS, Rev. 8