TLE4998C8(D)

General

Data Sheet

7

Revision 1.1, 2017-01

2.3

Principle of Operation

•

A magnetic flux is measured by a Hall-effect cell

•

The output signal from the Hall-effect cell is converted from analog to digital signals

•

The chopped Hall-effect cell and continuous-time A/D conversion ensure a very low and stable magnetic offset

•

A programmable low-pass filter to reduce noise

•

The temperature is measured and A/D converted

•

Temperature compensation is done digitally using a second-order function

•

Digital processing of the output value is based on zero field and sensitivity value

•

The output value range can be clamped by digital limiters

•

The final output value is represented by the data nibbles of the SPC protocol

2.4

Transfer Functions

The examples in Figure 2-2 show how different magnetic field ranges can be mapped to the desired output value

ranges.

•

Polarity Mode:

– Bipolar: Magnetic fields can be measured in both orientations. The limit points do not necessarily have to

be symmetrical around the zero field point

– Unipolar: Only north- or south-oriented magnetic fields are measured

•

Inversion: Both gain can be set to positive values, negative values or positive/negative values.

Figure 2-2

Examples of Operation

0

4095 /

65535

50

-50

100

-100

200

-200

0

0

B (mT)

B (mT)

B (mT)

0

0

0

4095 /

65535

4095 /

65535

Example 1:

-Bipolar

Example 2:

-Unipolar

-Big offset

Example 3:

- Bipolar

- Inverted (neg. gain)