The Histogram Analysis tool can be used to estimate the effective resolution of the ADC resulting from performance degradation caused by noise. Effective resolution is an indicator of the number of bits of ADC measurement resolution resulting from performance losses caused by noise generated by the various sources connected to the ADC when measuring a DC signal. The cumulative effect of noise coupling to the ADC output (from sources such as the input drive circuits, the reference drive circuit, the ADC power supply, and the ADC) is reflected in the standard deviation of the ADC output code histogram obtained by performing multiple conversions of a DC input applied to a given channel.

The histogram corresponding to a DC input is displayed by clicking the Capture button. The example capture shown in Figure 6-6 is captured with the EVM configured by remove jumpers from pin 1 and 2 of jumper JP5 and JP6, shorting pin [1-2] of JP1, JP2, JP3, and JP4 using 100-mil jumpers.

Figure 6-6 Histogram Analysis Tool