A3241 and A3242
Chopper-Stabilized
Unipolar Hall-Effect Switches
Package LH, 3-pin Surface Mount
GND
3
The A3241 and A3242 integrated circuits are unipolar Hall-effect switches with
digital outputs. These sensors are suited for operation over extended temperature
ranges, up to +150°C. Superior high-temperature performance is made pos-
sible through an Allegro
®
patented 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
fi
eld only, turning off in
the absence of such a south polarity
fi
eld.
The A3241 and A3242 are rated for operation between the ambient temperatures
–40°C and 85°C for the E temperature range, and –40°C to 150°C for the L tem-
perature range. The small geometries of the BiCMOS process allow these devices
to be provided in ultrasmall packages. The package styles available provide mag-
netically optimized solutions for most applications. Package LH is an SOT23W,
a miniature low-profile surface-mount package, while package UA is a three-lead
ultramini SIP for through-hole mounting. Each package is available in a lead (Pb)
free version, with 100% matte tin plated leadframes.
1
2
1
2
3
Package UA, 3-pin SIP
1
2
VOUT
GND
VCC
VOUT
3
VCC
1 2
3
Features and Benefits
Chopper stabilization
Output short circuit protection
Solid state reliability
Small size
Robust EMC capability
High ESD ratings (HBM)
Superior temperature stability
Extremely low switchpoint drift
Insensitive to physical stress
Reverse battery protection
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
..........................................
28 V
Reverse-Supply Voltage, V
RCC
........................
–18 V
Reverse-Supply Current, I
RCC
........................–2
mA
Output Off Voltage, V
OUT
..................................
28 V
Output Current, I
OUTSINK
...........
Internally Limited
Magnetic Flux Density, B .........................Unlimited
Operating Temperature
Ambient, T
A
, Range E..................
–40ºC to 85ºC
Ambient, T
A
, Range L................
–40ºC to 150ºC
Maximum Junction, T
J(MAX)
......................165ºC
Storage Temperature, T
S
..................
–65ºC to 170ºC
A3241-DS, Rev. 2
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
