Predicted results versus measured results

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Predicted results versus measured results

With this information, we can now estimate the residual voltages remaining after the

protection device and compare these results with the results obtained during ESD surge

measurements. For this comparison the IEC61000-4-2 in contact mode has been selected.

In the standard, the current levels are specified versus the charging voltage (Figure 11).

Figure 11. Extract of IEC61000-4-2 standard [page 12], current levels versus charge

From this table we can calculate the minimum and maximum current values that can be

found in our circuit, based on the tolerances specified (

±15% or ±30% versus typical

values). The expected values are summarized in Table 1.

a.STMicroelectronics thanks the International Electrotechnical Commission (IEC) for

permission to reproduce Information from its International Standard IEC 61000-4-2 ed.2.0

(2008).

All such extracts are copyright of IEC, Geneva, Switzerland. All rights reserved. Further

information on the IEC is available from www.iec.ch. IEC has no responsibility for the

placement and context in which the extracts and contents are reproduced by

STMicroelectronics, nor is IEC in any way responsible for the other content or accuracy

therein.

Table 1. Minimum, typical and maximum current values versus charge voltage

Peak current (±15%)

1

2

6.37

7.5

8.62

2.8

4

5.2

1.4

2

2.6

2

4

12.75

15

17.25

5.6

8

10.4

2.8

4

5.2

3

6

19.12

22.5

25.87

8.4

12

15.6

4.2

6

7.8

4

8

25.5

30

34.5

11.2

16

20.8

5.6

8

10.4