A3241 and A3242
Chopper-Stabilized Unipolar Hall-Effect Switches
Features and Benefits
Description
▪ Chopper stabilization
▫ Superior temperature stability
▫ Extremely low switchpoint drift
▫ Insensitive to physical stress
▪ Reverse battery protection
▪ Output short circuit protection
▪ Solid state reliability
▪ Small size
▪ Robust EMC capability
▪ High ESD ratings (HBM)
The A3241 and A3242 integrated circuits are unipolar Halleffect switches with digital outputs. These sensors are suited
for operation over extended temperature ranges, up to +150°C.
Superior high-temperature performance is made possible
through an Allegro® patented dynamic offset cancellation,
which reduces the residual offset voltage normally caused
by device overmolding, temperature excursions, and thermal
stress.
Packages: 3 pin SOT23W (suffix LH), and
3 pin SIP (suffix UA)
The A3241 and A3242 Hall-effect switches include the
following on a single silicon chip: voltage regulator, Hallvoltage generator, small-signal amplifier, chopper stabilization,
Schmitt trigger, and a short circuit protected open-drain output.
Advanced BiCMOS wafer fabrication processing is used to
take advantage of low-voltage requirements, component
matching, very low input-offset errors, and small component
geometries.
The integrated voltage regulator permits operation from 3.6 to
24 V. The unipolar family members operate with a sufficient
south polarity field only, turning off in the absence of such a
south polarity field.
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Not to scale
Functional Block Diagram
VCC
Regulator
Amp
Low-Pass
Filter
Amp
Sample and Hold
Dynamic Offset
Cancellation
To All Subcircuits
VOUT
Control
Current Limit
<1Ω
GND
A3241-DS, Rev. 4
