Output amplitute from an NCO

[Altera_Forum]

Am i right in thinking that the output amplitutde from the NCO is not constant over different frequencies?

[Altera_Forum]

I am going to correct my final data on my pc as a lot easier then trying to correct for it on the FPGA. 

 Thanks alot for your help in this.

[Altera_Forum]

I think that outputs of DAC have amplitude diffirent with frequences diffirent. Because ouput of DAC forma sin(x)/x.

[Altera_Forum]

Hi,  

I have the same problem with stratix2 dsp evaluation board. I built a simple fsk modulator on NCO. The output is 10 kHz for '0' and 15khz for '1'. I use all 14 bits of DAC. The amplitudes differs about 50-100 mVolts. In the simulations everything looks ok. I also try to understand what the problem is.

[Altera_Forum]

In this case you can easily overcome the difference by prescaling both to become equal after DAC(simplest case of equaliser)

[Altera_Forum]

--- Quote Start ---  Hi,  I have the same problem with stratix2 dsp evaluation board. I built a simple fsk modulator on NCO. The output is 10 kHz for '0' and 15khz for '1'. I use all 14 bits of DAC. The amplitudes differs about 50-100 mVolts. In the simulations everything looks ok. I also try to understand what the problem is.  --- Quote End ---    Do You Have the project to share?