Programmable Linear Hall Effect Sensor ICs with Analog Output

Available in a Miniature Thin Profile Surface Mount Package

A1381, A1382,

A1383, and A1384

8

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Quiescent Voltage Output Drift Through Temperature Range

Due to internal component tolerances and thermal considerations,

of specification, the Quiescent Voltage Output Drift Through

∆V

OUT(Q)

V

=

.

(3)

Sensitivity

The presence of a south polarity magnetic field, per-

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:

V

BPOS – BNEG

Sens =

,

(4)

where BPOS and BNEG are two magnetic fields with opposite

polarities.

Guaranteed Sensitivity Range

The magnetic sensitivity, Sens,

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

Refer to the Average Quiescent

Voltage Output Step Size section for a conceptual explanation.

Sensitivity Programming Resolution

Refer to the Quiescent

Voltage Output Programming Resolution section for a conceptual

explanation.

Sensitivity Temperature Coefficient

Device sensitivity changes

as temperature changes, with respect to its programmed sensitiv-

150°C, and calculated relative to the nominal sensitivity program

Sens

Sens

T1

T2–T1

1

TC

,

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

(5)

where T1 is the nominal Sens programming temperature of 25°C,

ideal value of Sens over the full ambient temperature range,

Sens

Sens

(6)

Guaranteed Sensitivity Temperature Coefficient Range

The

magnetic sensitivity temperature coefficient can be programmed

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

Refer

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

Second order

sensitivity temperature coefficient effects cause the magnetic

sensitivity, Sens, to drift from its ideal value over the operating

as:

Sens

Sens

IDEAL(TA)

∆Sens

(7)

Sensitivity Drift Due to Package Hysteresis

Package stress and

during and after temperature cycling.