The time-domain display tool allows visualization of the ADC response to a given input signal. This tool is useful for studying the behavior of and debugging any gross problems with the ADC or drive circuits. Trigger a data capture of the selected number of samples from the ADS125P08 EVM by using the Capture button in Figure 4-8. The time-domain plot has Time on the x-axis and by default shows the corresponding Voltage on the y-axis relative to the specified reference voltage.

The Measurements control on the bottom of Figure 4-8 calculates the code range, the mean code, and the code standard deviation. Switching pages to any of the Analysis tools described in the subsequent sections causes calculations to be performed on the same set of data.

Finally, Figure 4-8 specifically shows a time-domain capture where the ADC sequencer is disabled and the ADC is capturing 1024 samples of data.

Figure 4-9 shows a time-domain capture where the ADC sequencer is enabled and NUM_CONV = 1 in each enabled step such that the GUI can capture more than one sequence. In this example, the GUI captures 1024 sequences where each sequence is comprised of three measurements: the AVDD supply voltage in blue, the IOVDD supply voltage in orange, and an internal short in pink. Additionally, the GUI displays the first conversion latency of each measurement and the corresponding effective data rate. The first conversion latency is comprised of the complete digital filter settling resulting from the FLTR_OSR and Step Filter Mode fields, as well as any additional delay entered in the Delay in Tmods field, if applicable. The first conversion latency can therefore be different for different steps.

Figure 4-10 shows a time-domain capture where the ADC sequencer is enabled and at least one step has NUM_CONV > 1. The GUI cannot capture more than one sequence under these conditions. In this example, the ADC uses the same settings used in Figure 4-10 except that NUM_CONV = 64 on the internal short step. Therefore, the GUI captures a single conversion on the first enabled step in blue, a single conversion on the second enabled step in orange, and 64 consecutive conversions on the third enabled step in pink. Importantly, the noise values in the Measurements control can show NaN or 0 because noise cannot be calculated on a single value.