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Solution for nonflat frequency response of an DAC output in AD9959

Question asked by hoainampt2000 on Jul 6, 2015
Latest reply on Jul 7, 2015 by KennyG

Hi All,

I try generate frequency sweep signal using DDS (AD9959).

As i know, The Amplitude of the output signal spectrum multiplies by the sinc envelope.

But AD9959 haven't inverse sinc. Have you got as solution to flatten amplitude of output signal?

Below is the picture of Frequency Sweep at DAC Output.

My configure is:  system clock : 500 Mhz,

Figure 1: Frequency Sweep with frequency:  0 - 200 Mhz

Figure 2: Pulse of Frequency Sweep  with  frequency from 127.5 -  172.5 Mhz

Figure 3: Spectrum of signal on Figure 2.