A3283LLTTR-T Allegro Microsystems Inc, A3283LLTTR-T Datasheet - Page 9

• Manufacturer Part Number: A3283LLTTR-T
• Description: IC SWITCH HALL EFFECT SOT-89
• Manufacturer: Allegro Microsystems Inc
• Type: Bipolar Latchr

Specifications of A3283LLTTR-T

• Sensing Range: 180G Trip, -180G Release
• Voltage - Supply: 4.2 V ~ 24 V
• Current - Supply: 8mA
• Current - Output (max): 25mA
• Output Type: Digital, Open Collector
• Features: Regulated Voltage
• Operating Temperature: -40°C ~ 150°C
• Package / Case: SOT-89-3
• Magnetic Type: Latch
• Operating Supply Voltage (min): 4.2V
• Operating Supply Voltage (typ): 5/9/12/15/18V
• Operating Supply Voltage (max): 24V
• Output Current: 25mA
• Mag Sensor Operate Point (g): 180Gs
• Mag Sensor Release Point (g): -180Gs
• Mag Sensor Hysteresis(g): 300Gs
• Package Type: SOT-89
• Pin Count: 3 +Tab
• Mounting: Surface Mount
• Operating Temp Range: -40C to 150C
• Operating Temperature Classification: Automotive
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

A3280, A3281
and
Chopper-Stabilized Technique. The Hall element can be
considered as a resistor array similar to a Wheatstone bridge. A
large portion of the offset is a result of the mismatching of these
resistors. These devices use a proprietary dynamic offset cancel-
lation technique, with an internal high-frequency clock to reduce
the residual offset voltage of the Hall element that is normally
caused by device overmolding, temperature de pen den cies, and
thermal stress. The chopper-stabilizing technique cancels the
mismatching of the resistor circuit by changing the direction of
the current fl owing through the Hall plate using CMOS switches
and Hall voltage measurement taps, while maintaing the Hall-
voltage signal that is induced by the external magnetic fl ux. The
signal is then captured by a sample-and-hold circuit and further
processed using low-offset bipolar circuitry. This technique
produces devices that have an extremely stable quiescent Hall
output voltage, are immune to thermal stress, and have precise
recoverability after temperature cycling. This technique will
also slightly degrade the device output repeatability. A relatively
high sampling frequency is used in order that faster signals can
be processed.
found in: Technical Paper STP 97-10, Monolithic Magnetic Hall
Sensing Using Dynamic Quadrature Offset Cancellation and
Technical Paper STP 99-1, Chopper-Stabilized Amplifi ers With A
Track-and-Hold Signal Demodulator.
Operation. The output of these devices switch es low (turns
on) when a magnetic fi eld perpendicular to the Hall element
exceeds the operate point threshold (B
output is capable of sinking 25 mA and the output voltage is
V
suffi cient strength towards the branded surface of the device
will turn the device on; removal of the south pole will leave the
device on. When the magnetic fi eld is reduced below the release
point (B
ence in the magnetic operate and release points is the hysteresis
(B
ing of the output even in the presence of external mechanical
vibration and electrical noise.
B
state. The correct state is warranted after the fi rst excursion
beyond B
OUT(SAT)
OP
hys
More detailed descriptions of the circuit operation can be
Powering up in the absence of a magnetic fi eld (less than
and higher than B
It is strongly recommended that an external bypass ca pac i tor
) of the device. This built-in hysteresis allows clean switch-
A3283
RP
. Note that the de vice latch es; that is, a south pole of
OP
), the device output goes high (turns off). The dif fer-
or B
RP
.
RP
) will allow an indeterminate output
OP
). After turn-on, the
FUNCTIONAL DESCRIPTION
Chopper-Stabilized, Precision
Hall-Effect Latches
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
8