Continuous-Time Ratiometric

Linear Hall Effect Sensor ICs

A1302

4

Allegro MicroSystems, LLC

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

CHARACTERISTIC DEFINITIONS

Quiescent Output Voltage

In the quiescent state (no significant magnetic field: B = 0),

mal considerations, there is a tolerance on the quiescent output

purposes of specification, the quiescent output voltage as a func-

where Sens is in mV/G, and the result is the device equivalent

accuracy, in gauss (G), applicable over the entire operating tem-

perature range.

Sensitivity

The presence of a south-polarity (+B) magnetic field, perpen-

dicular to the branded face of the device package, increases the

of a north polarity (–B) magnetic field, in the same orientation,

proportionally decreases the output voltage from its quiescent

value. This proportionality is specified as the magnetic sensitiv-

ity of the device and is defined as:

The stability of the device magnetic sensitivity as a function of

Ratiometric

The A1301 and A1302 feature a ratiometric output. This means

The ratiometric change (%) in the quiescent voltage output is

defined as:

and the ratiometric change (%) in sensitivity is defined as:

Linearity and Symmetry

The on-chip output stage is designed to provide linear output at

a supply voltage of 5 V. Although the application of very high

magnetic fields does not damage these devices, it does force

their output into a nonlinear region. Linearity in percent is mea-

sured and defined as:

and output symmetry as:

∆

–

=

(1)

2

B

Sens

–

=

∆

–

=

× 100%

(2)

(3)

∆

× 100%

(4)

=

× 100%

∆

(5)

=

× 100%

Lin+

2 (

–

(6)

=

× 100%

Lin–

2(

–

(7)

–

=

× 100%

Sym

(8)