A3230
Chopper-Stabilized Hall-Effect Bipolar Switch
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)
Description
The A3230 Hall-effect sensor is a temperature stable, stress-
resistant bipolar switch. This sensor is the most sensitive
Hall-effect device in the Allegro
®
bipolar switch family and
is intended for ring-magnet sensing. Superior high-temperature
performance is made possible through an Allegro patented
dynamic offset cancellation that utilizes chopper-stabilization.
This method reduces the offset voltage normally caused by
device overmolding, temperature dependencies, and thermal
stress.
The A3230 includes the following on a single silicon chip:
a 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 takes advantage of low-voltage
requirements, component matching, very low input-offset
errors, and small component geometries.
The A3230 Hall-effect bipolar switch turns on in a south
polarity magnetic field of sufficient strength and switches
off in a north polarity magnetic field of sufficient strength.
Because the output state is not defined if the magnetic field is
Packages: 3 pin SOT23W (suffix LH), and
3 pin SIP (suffix UA)
Continued on the next page…
Not to scale
Functional Block Diagram
VCC
Regulator
To All Subcircuits
Sample and Hold
Dynamic Offset
Cancellation
Low-Pass
Filter
VOUT
Amp
Control
Current Limit
<1Ω
GND
3230-DS, Rev. 2
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
