Continuous-Time Ratiometric

Linear Hall Effect Sensor ICs

A1302

5

Allegro MicroSystems, Inc.

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 sig-

component tolerances and thermal considerations, there is a

tion, the quiescent output voltage as a function of temperature,

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, perpendicular to the branded face of the device package,

application 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

sensitivity 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

and the magnetic sensitivity, Sens, are proportional to the supply

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 measured and defined as:

and output symmetry as:

–

=

(1)

2B

Sens

–

=

–

=

× 100%

(2)

(3)

5 V

× 100%

(4)

5 V

=

× 100%

CC

)

(5)

=

× 100%

Lin+

–

(6)

=

× 100%

Lin–

–

(7)

–

=

× 100%

Sym

(8)