A3245_06 Datasheet, PDF (1/12 Pages) Allegro MicroSystems – Chopper-Stabilized Omnipolar Hall-Effect Switches

A3245
Chopper-Stabilized Omnipolar Hall-Effect Switches
Features and Benefits
▪ Omnipolar operation
▪ 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)
Packages: 3 pin SOT23W (suffix LH), and
3 pin SIP (suffix UA)
Description
The A3245 integrated circuit is an omnipolar, ultrasensitive
Hall-effect switch with a digital output. This sensor has an
integrated regulator permitting operation to 24 V, making it
the first omnipolar switch available for operation to 24 V.
This device is especially 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.
TheA3245 Hall-effect switch includes 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 omnipolar operation of the A3245 allows activation with
either a north or a south polarity field of sufficient strength. In
the absence of a magnetic field, the output is off. This patented
Not to scale
VCC
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Functional Block Diagram
Amp
Amp
Regulator
To All Subcircuits
Control
Current Limit
VOUT
<1Ω
GND
A3245-DS, Rev. 2