A3290 and A3291
Chopper-Stabilized, Precision Hall-Effect Latches for
Consumer and Industrial Applications
FEATURES AND BENEFITS
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DESCRIPTION
Symmetrical switchpoints
Resistant to physical stress
Superior temperature stability
Output short-circuit protection
Operation from unregulated supply
Reverse battery protection
Solid-state reliability
Small package size
The A3290 and A3291 Hall-effect latches are extremely
temperature-stable and stress-resistant sensor ICs, especially
suited for operation over extended temperature ranges (up
to 125°C). Superior high-temperature performance is made
possible through dynamic offset cancellation, which reduces
the residual offset voltage normally caused by device package
overmolding, temperature dependencies, and thermal stress. The
two devices are identical except for their magnetic switchpoints.
They are not intended for automotive applications.
Both devices include, on a single silicon chip, a voltage regulator,
a Hall voltage generator, a small-signal amplifier, chopper
stabilization, a Schmitt trigger, and a short-circuit protected
open-drain output to sink up to 25 mA. A south polarity magnetic
field of sufficient strength is required to turn the output on. A
north polarity field of sufficient strength is necessary to turn
the output off. An onboard regulator permits operation with
supply voltages in the range of 3 to 24 V.
Packages:
3-Pin SOT23W
(suffix LH)
3-Pin SIP (suffix UA)
Two package styles provide a magnetically optimized package
for most applications: type LH is a miniature SOT23W lowprofile surface-mount package, and type UA is a three-pin
ultramini SIP for through-hole mounting. Both packages are
lead (Pb) free with 100% matte-tin leadframe plating.
Not to scale
(A3290)
(A3291)
VCC
Amp
Sample and Hold
Dynamic Offset
Cancellation
Regulator
OUT
Low-Pass
Filter
Control
Current Limit
1Ω
GND
Functional Block Diagram
A3290-DS, Rev. 15
