06-04-2018 01:00 PM - edited 06-04-2018 01:06 PM
in the DDS .pdf, it mention the DDS can generate waveform up to its CLK So for 200mhz clk, 12bit, it can generate wave upto 200mhz, 76db But Nyquist indicate Fs/2, so how does DDS generate 200Mhz wave, when its clk/Fs is at 200Mhz? However, in Xilinx ip doc, it says it can generate from 0 to 200Mhz, even its clk is 200mhz, how is that possible.
ok I think the IP map 0.5fs to 1fs into -0.5fs to 0?
06-04-2018 01:25 PM
have a search of the forum
this has come up a few times,
DDS as you say can not generate above 1/2 the clock frequency, unless you use harmonics,
06-04-2018 01:25 PM
have a search of the forum
this has come up a few times,
DDS as you say can not generate above 1/2 the clock frequency, unless you use harmonics,
06-04-2018 01:29 PM
No, the DDS cannot violate Nyquist sampling. For a single sine output, a 100 MHz clock will allow generation of a sine wave up to 50 MHz.. For a sine/cosine output, the range then becomes -50 MHz to +50 MHz (complex data), which is technically a span of 100 MHz. But the peak frequency is still half the clock rate.