CDBCapture+

8

DS327F1

For high resolution converters, as shown in

Figure 7, the DNL graph is very compressed, since

65534 codes are displayed over a length of several

inches. This makes it very difficult to get a com-

plete picture of the overall performance of the A/D

converter. The DNL histogram screen, shown in

Figure 8, can be used to get a better picture of the

parts DNL performance. The histogram displays

the same data that is in Figure 7, but breaks the

DNL error into groups, shown on the horizontal ax-

is, and shows the number of codes within each

group on the vertical axis. This view shows the rel-

ative number of codes that have large positive or

negative DNL values, as opposed to a perfect con-

verter where all the values would be under one ver-

tical bar, corresponding to zero DNL. Statistical

values for the entire distribution are displayed to

the left of the histogram.

Figure 8. Differential Nonlinearity Histogram