Hi,

We are currently using DAC in Normal Mode (Input BW = 50MHz and Sampling rate = 200MSPS). However we prefer not to have any attenuation over this band. However in the Transfer function figure shown in the datasheet, it seems the sinc roll-off will affect our signal. We would like to Pre-Equalise this Roll-off. Can you share us the sinc response of the DAC in tabular form so that it will be easier for us to implement pre-emphasis.

We are also interested in Return to Zero mode. It looks that in this mode, the roll-off will be minimum. Can you explain this mode? Will there be any effect on the DAC output while choosing this mode apart from output power reduction? Will there be any SNR degradation or any other issues to be considered in this mode?

We are currently using DAC in Normal Mode (Input BW = 50MHz and Sampling rate = 200MSPS). However we prefer not to have any attenuation over this band. However in the Transfer function figure shown in the datasheet, it seems the sinc roll-off will affect our signal. We would like to Pre-Equalise this Roll-off. Can you share us the sinc response of the DAC in tabular form so that it will be easier for us to implement pre-emphasis.

This is stardard for all DACs

Equation for SINC rolloff

H(f) = SINC(PI*f/fs) = SIN(PI*f/fs)/ (PI*f/fs)

are also interested in Return to Zero mode. It looks that in this mode, the roll-off will be minimum. Can you explain this mode? Will there be any effect on the DAC output while choosing this mode apart from output power reduction? Will there be any SNR degradation or any other issues to be considered in this mode?

IWe clock data in on rising and falling edges of DAC clock (CLKP/N) on this DAC. In normal mode the same sample is clocked in twice. In Return to zero, sample is clocked on rising edge of DAC clock and a Zero value is clocked in on falling edges and in mixed mode the smaple is clocked in on rising edge an invereted sample is clocked in on the falling edge.

the frequency response is shown below of all three modes is shown in Figure 65 of the data sheet.on page 29.