RATIOMETRIC,

LINEAR HALL-EFFECT SENSORS

FOR HIGH-TEMP. OPERATION

www.allegromicro.com

SENSOR LOCATION

APPLICATIONS INFORMATION

Calibrated linear Hall devices, which can be used to

determine the actual flux density presented to the sensor in a

particular application, are available.

For safe, reliable operation, the output should not be

pulled above the supply voltage or pulled below the device

ground.

For optimum performance, a 100 pF capacitor between

the output and ground should be added.

The nominal sensitivity is factory set to compensate for

the temperature coefficient of samarium-cobalt magnets

(-0.02%/

°C).

The ratiometric feature is especially valuable when these

devices are used with an analog-to-digital converter. A/D

converters typically derive their LSB step size by ratioing off a

reference voltage line. If the reference voltage varies, the LSB

will vary proportionally. This is a major error source in many

sensing systems. The A3507/08– can eliminate this source of

error by their ratiometric operation. Because their gain and

offsets are proportional to the supply voltage, if they are

powered from the A/D reference voltage, the sensor output

voltage will track changes in the LSB value.

Hall-effect applications information is available in the

application note “Linear Hall-Effect Sensors” (AN 27702),

which can be found in the latest issue of Allegro Electronic

Data Book, AMS-702, or at

www.allegromicro.com

1

3

2

Dwg. MH-011-6A

0.018"

0.46 mm

NOM

BRANDED

SURFACE

ACTIVE AREA DEPTH

0.082"

2.07 mm

0.055"

1.40 mm

A

B

≈ N x 6.9 G/A

Dwg. AH-005A

TYPICAL CURRENT-SENSING APPLICATION