A1324LLHLT-T Datasheet, PDF (6/12 Pages) Allegro MicroSystems – Low Noise, Linear Hall Effect Sensor ICs with Analog Output

A1324, A1325,
and A1326
Linear Hall Effect Sensor ICs with Analog Output
T_A = 25°C, and Sens_(25°C)1 is the value of sensitivity at T_A = 25°C
after temperature cycling T_A up to 150°C, down to –40°C, and
back to up 25°C.
Linearity Sensitivity Error The 132x is designed to provide
linear output in response to a ramping applied magnetic field.
Consider two magnetic fields, B1 and B2. Ideally the sensitivity
of a device is the same for both fields for a given supply voltage
and temperature. Linearity sensitivity error is present when there
is a difference between the sensitivities measured at B1 and B2.
Linearity Sensitivity Error is calculated separately for the positive
(LIN_ERR+) and negative (LIN_ERR– ) applied magnetic fields. Lin-
earity Sensitivity Error (%) is measured and defined as:

Lin_ERR+ = _1–

Sens_B(++)
Sens_B(+)



×
100%

Lin_ERR– = _1–

Sens_{B(– –)}
Sens_B(–)



×
100%
(7)
and
Lin_ERR = max(| Lin_ERR+| , |Lin_ERR–| )
(8)
where:
Sens_Bx
=
^|VOUT(Bx)_B^–_X^VOUT(Q)|



(9)
and B(++), B(+), B(– –), and B(–) are positive and negative mag-
netic fields with respect to the quiescent voltage output such that
|B(++)| > |B(+)| and |B(– –)| > |B(– )| .
Symmetry Sensitivity Error The magnetic sensitivity of a
device is constant for any two applied magnetic fields of equal
magnitude and opposite polarities.
Symmetry Error (%), is measured and defined as:
Sym_ERR

= _1–

Sens_B(+)
Sens_B(–)

 ^×100%

(11)
where Sens_Bx is defined as in equation 9, and B(+), B(–) are posi-
tive and negative magnetic fields such that |B(+)| = |B(–)|.
Ratiometry Error The A132x features a ratiometric output.
This means that the quiescent voltage output, V_OUT(Q) , magnetic
sensitivity, Sens, and clamp voltages, V_CLPHIGH and V_CLPLOW ,
are proportional to the supply voltage, V_CC. In other words, when
the supply voltage increases or decreases by a certain percent-
age, each characteristic also increases or decreases by the same
percentage. Error is the difference between the measured change
in the supply voltage, relative to 5 V, and the measured change in
each characteristic.
The ratiometric error in quiescent voltage output, Rat_VOUT(Q)
(%), for a given supply voltage, V_CC, is defined as:
Rat_VOUT(Q)

= _1–

V_OUT(Q)VCC
V_CC
cV_OUT(Q)5V
c V



×
100%
(12)
The ratiometric error in magnetic sensitivity, Rat_SENS (%), for a
given supply voltage, V_CC, is defined as:

Rat_VOUT(Q) = _1–

Sens_VCC
V_CC
cSens_5V
cV



×
100%
(13)
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