SBASB20 September 2024 DDS39RF10 , DDS39RFS10
PRODUCTION DATA
Non-return-to-zero (NRZ) mode is the standard zero-order hold mode. The timing diagram for NRZ mode is given in Figure 7-3. The sample is output from the DAC on the CLK rising edge and held until the rising edge. This output waveform can be thought of as a rectangular filter in time domain resulting in a sinc response in the frequency domain. The result is a frequency response that has significant power loss in the 2nd and 3rd Nyquist zones and a null at the sampling rate and is meant for 1st Nyquist zone operation only. A plot of the frequency response of NRZ mode is shown in Figure 7-4.