Ultrasensitive Two-Wire Chopper-Stabilized
Unipolar Hall Effect Switches
A1145 and
A1146
2
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
feature on-chip transient protection and a Zener clamp to protect
against overvoltage conditions on the supply line.
The output currents of the A1146 switches HIGH in the presence
of a south (+) polarity magnetic field of sufficient strength, and
switches LOW otherwise, as in the presence of a weak field or a
north (–) polarity field. The A1145 has an opposite output: the
currents switch LOW in the presence of a south-polarity magnetic
field of sufficient strength, and switch HIGH otherwise.
Both versions are offered in two package styles. The LH is a SOT-
23W, miniature low-profile package for surface-mount applications.
The UA is a three-lead ultramini SIP for through-hole mounting.
Each package is available in a lead (Pb) free version (suffix, –T)
with 100% matte tin plated leadframe. Field-programmable versions
also available: A1185 and A1186.
Absolute Maximum Ratings
Characteristic Symbol Notes Rating Units
Supply Voltage V
CC
28 V
Reverse Supply Voltage V
RCC
–18 V
Magnetic Flux Density B Unlimited G
Operating Ambient Temperature T
A
Range E –40 to 85 ºC
Range L –40 to 150 ºC
Maximum Junction Temperature T
J
(max) 165 ºC
Storage Temperature T
stg
–65 to 170 ºC
Description (continued)
Selection Guide
Part Number Packing
1
Package
Operating Ambient
Temperature, T
A
(°C)
Output Level in
South (+) Field
2
A1145ELHLT-T
3
Tape and Reel, 3000 pieces/reel Surface Mount
–40 to 85 Low
A1145EUA-T
4
Bulk Bag, 500 pieces/bag Through Hole
A1146ELHLT-T
3
Tape and Reel, 3000 pieces/reel Surface Mount
–40 to 85
High
A1146EUA-T
4
Bulk Bag, 500 pieces/bag Through Hole
A1146LLHLT-T
3
Tape and Reel, 3000 pieces/reel Surface Mount
–40 to 150
A1146LUA-T
4
Bulk Bag, 500 pieces/bag Through Hole
1
Contact Allegro for additional packing options.
2
South (+) magnetic fields must be of sufficient strength.
3
This variant is in production, however, it has been deemed Pre-End of Life. The product is approaching end of life. Within a minimum of
6 months, the device will enter its final, Last Time Buy, order phase. Status change: January 31, 2011. Suggested replacements: for the
A1145ELHLT-T use the A1155LLHLX-T, for the A1146ELHLT-T and the A1146LLHLT-T use the A1156LLHLX-T.
4
Variant is in production but has been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of the variant is
currently restricted to existing customer applications. The variant should not be purchased for new design applications because obsoles-
cence in the near future is probable. Samples are no longer available. Status change: January 31, 2011.
