A1184_06 Datasheet, PDF (1/14 Pages) Allegro MicroSystems – Standard Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall-Effect Switches

A1184
Standard Two-Wire Field-Programmable Chopper-Stabilized
Unipolar Hall-Effect Switches
Features and Benefits
▪ Chopper stabilization
▫ Low switchpoint drift over operating
temperature range
▫ Low sensitivity to stress
▪ Field programmable for optimized switchpoints
▪ On-chip protection
▫ Supply transient protection
▫ Reverse-battery protection
▫ On-board voltage regulator
▫ 3.5 to 24 V operation
Packages: 3 pin SOT23W (suffix LH), and
3 pin SIP (suffix UA)
Description
The A1184 device is a standard, two-wire, unipolar, Hall effect
switches. The operate point, B_OP, can be field-programmed,
after final packaging of the sensor and placement into the
application. This advanced feature allows the optimization of
the sensor switching performance, by effectively accounting
for variations caused by mounting tolerances for the device
and the target magnet.
This family of devices are produced on the Allegro
MicroSystems advanced BiCMOS wafer fabrication process,
which implements a patented, high-frequency, chopper-
stabilization technique that achieves magnetic stability and
eliminates the offsets that are inherent in single-element devices
exposed to harsh application environments. Commonly found
in a number of automotive applications, the A1184 is utilized to
sense: seat track position, seat belt buckle presence, hood/trunk
latching, and shift selector position.
Two-wire unipolar switches are particularly advantageous
in price-sensitive applications, because they require one
less wire than the more traditional open-collector output
switches. Additionally, the system designer gains inherent
diagnostics because output current normally flows in either
Not to scale
V+
VCC
0.01 uF
Continued on the next page…
Functional Block Diagram
Program/Lock
Programming
Logic
Offset
Clock/Logic
Amp
Low-Pass
Filter
Regulator
GND
Package UA Only
GND
A1184-DS, Rev. 4