A1381 ALLEGRO [Allegro MicroSystems], A1381 Datasheet - Page 8

• Manufacturer Part Number: A1381
• Description: Programmable Linear Hall Effect Sensors with Analog Output Available in a Miniature Thin Profile Surface Mount Package
• Manufacturer: ALLEGRO [Allegro MicroSystems]

A1381, A1382,
A1383, and A1384
Quiescent Voltage Output Drift Through Temperature Range
Due to internal component tolerances and thermal considerations,
the quiescent voltage output, V
value over the operating ambient temperature, T
of specification, the Quiescent Voltage Output Drift Through
Temperature Range, ∆V
Sensitivity
pendicular to the branded surface of the package face, increases
the output voltage from its quiescent value toward the supply
voltage rail (assuming that the polarity bit, POL, is in its initial
state of logic 0). The amount of the output voltage increase is
proportional to the magnitude of the magnetic field applied.
Conversely, the application of a north polarity field decreases the
output voltage from its quiescent value. This proportionality is
specified as the magnetic sensitivity, Sens (mV/G), of the device,
and it is defined as:
where BPOS and BNEG are two magnetic fields with opposite
polarities.
Guaranteed Sensitivity Range
can be programmed around its nominal value, 2.5 to 7.5 mV/G
depending on device type, within the sensitivity range limits:
Sens(min) and Sens(max). Refer to the Guaranteed Quiescent
Voltage Output Range section for a conceptual explanation of
how value distributions and ranges are related.
Average Sensitivity Step Size
Voltage Output Step Size section for a conceptual explanation.
Sensitivity Programming Resolution
Voltage Output Programming Resolution section for a conceptual
explanation.
Sensitivity Temperature Coefficient
as temperature changes, with respect to its programmed sensitiv-
ity temperature coefficient, TC
150°C, and calculated relative to the nominal sensitivity program
∆V
The presence of a south polarity magnetic field, per-
OUT(Q)
Sens =
=
V
OUT(Q)
OUT(Q)(TA)
V
OUT(BPOS)
BPOS – BNEG
OUT(Q)
SENS
(mV), is defined as:
Refer to the Average Quiescent
The magnetic sensitivity, Sens,
–V
. TC
– V
, may drift from its nominal
OUT(Q)(25°C)
Device sensitivity changes
Refer to the Quiescent
OUT(BNEG)
SENS
Programmable Linear Hall Effect Sensors with Analog Output
Available in a Miniature Thin Profile Surface Mount Package
is programmed at
A
. For purposes
.
,
(3)
(4)
ming temperature of 25°C. TC
where T1 is the nominal Sens programming temperature of 25°C,
and T2 is the TCSENS programming temperature of 150°C.
The ideal value of Sens over the full ambient temperature range,
SensIDEAL(TA), is defined as:
Guaranteed Sensitivity Temperature Coefficient Range
magnetic sensitivity temperature coefficient can be programmed
within its limits: TC
Guaranteed Quiescent Voltage Output Range section for a con-
ceptual explanation of how value distributions and ranges are
related.
Average Sensitivity Temperature Coefficient Step Size
to the Average Quiescent Voltage Output Step Size section for a
conceptual explanation.
Sensitivity Temperature Coefficient Programming Resolution
Refer to the Quiescent Voltage Output Programming Resolution
section for a conceptual explanation.
Sensitivity Drift Through Temperature Range
sensitivity temperature coefficient effects cause the magnetic
sensitivity, Sens, to drift from its ideal value over the operating
ambient temperature range, T
sensitivity drift through temperature range, ∆Sens
as:
Sensitivity Drift Due to Package Hysteresis
relaxation can cause the device sensitivity at T
during and after temperature cycling.
TC
Sens
∆Sens
Sens
IDEAL(TA)
TC
=
⎛
⎜ ⎜
⎝
=
Sens
Sens
Sens
Sens
T2
=
Sens
(max) and TC
TA
Sens
– Sens
– Sens
T1
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
IDEAL(TA)
A
T1
SENS
. For purposes of specification, the
T1
[100% + TC
IDEAL(TA)
×
(%/°C) is defined as:
100%
Sens
(min). Refer to the
⎞
⎟ ⎟
⎠
×
⎛
⎜ ⎜
⎝
T2–T1
100%
SENS
1
A
Package stress and
= 25°C to change
Second order
⎞
⎟ ⎟
⎠
TC
(T
A
.
,
, is defined
–T1)]
Refer
The
(6)
(7)
(5)
8