Description
The A3240 Hall-effect switch is an extremely tempera-
ture-stable and stress-resistant sensor especially suited for
operation over extended tem per a ture ranges to +150°C.
Superior high-temperature per for mance is made possible
through dynamic offset cancellation, which reduces the
residual offset voltage normally caused by device overmolding,
tem per a ture de pen den cies, and thermal stress.
The device includes on a single silicon chip a voltage regulator,
Hall-voltage generator, small-signal amplifier, chopper
sta bi li za tion, Schmitt trigger, and a short-circuit protected
open-collector output to sink up to 25 mA. A south pole of
sufficient strength will turn the output on. An on-board regulator
permits operation with supply voltages of 4.2 to 24 volts.
Three package styles provide a magnetically op ti mized pack age
for most ap pli ca tions. Package type LH is a modified SOT23W
surface-mount package, LT is a miniature SOT89/TO-243AA
transistor package for surface-mount applications; while UA is
a three-lead ultra-mini-SIP for through-hole mounting. The LH
and UA packages are also available in a lead (Pb) free version
(suffix, –T) , with a 100% matte tin plated leadframe.
27621.20h
Features and Benefits
▪ Resistant to Physical Stress
▪ Superior Temperature Stability
▪ Output Short-Circuit Protection
▪ Operation From Unregulated Supply
▪ Reverse Battery Protection
▪ Sol id-State Reliability
▪ Small Size
Chopper-Stabilized, Precision
Hall-Effect Switch
Packages:
Functional Block Diagram
Not to scale
A3240
Dwg. FH-020-1
GROUND
OUTPUT
<17
X
DYNAMIC
OFFSET CANCELLATION
SUPPLY
CONTROL
CURRENT
LIMIT
REG.
SAMPLE
& HOLD
LOW-PASS
FILTER
TO ALL
SUBCIRCUITS
3-pin SOT89
(LT package)
3-pin SOT23W
(LH package)
3-pin SIP
(UA package)
