5 Summary

The analog input or output bandwidth of a data converter is an important requirement when evaluating one to integrate into the system design, especially as converters move into the GHz range and beyond. Using the fundamental frequency response measurement method is an effective way to properly measure and collect the bandwidth response of the data converter and the frontend network used to acquire all passband flatness metrics.

When capturing the bandwidth for either an ADC or a DAC, remember to back calculate out any additional connection losses in setup, position the NCO appropriately when using digital features such as a DDC and DUC, and adjust for any output modes or filters used within the output response of the DAC. Finally, add lossy pads on the equipment cable to minimize standing waves. Adhering to these recommendations helps produce the best bandwidth results and mitigate ripple in the next design.