Description
The A3241 and A3242 integrated circuits are unipolar Hall-
effect switches with digital outputs. These devices are suited
for operation over extended temperature ranges, up to +150°C.
Superior high-temperature performance is made possible
through an Allegro
®
dynamic offset cancellation, which
reduces the residual offset voltage normally caused by
device overmolding, temperature excursions, and thermal
stress.
The A3241 and A3242 Hall-effect switches include the
following on a single silicon chip: voltage regulator, Hall-
voltage 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.
A3241-DS, Rev. 16
Features and Benefits
▪ 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)
Chopper-Stabilized Unipolar Hall-Effect Switches
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Functional Block Diagram
Not to scale
Packages: 3 pin SOT23W (suffix LH), and
3 pin SIP (suffix UA)
A3241 and A3242
Regulator
GND
VCC
VOUT
Control
Current Limit
<1Ω
Dynamic Offset
Cancellation
Sample and Hold
To All Subcircuits
Amp
Low-Pass
Filter
Amp
