How to define or calculate the DAC output noise floor?

[karote]

How to define or calculate the DAC output noise floor? The intention is to produce 100 MHz real IF out of the DAC. I would need to konw the noise floor, since it affects the noise level at antenna.

Is there a specific parameters in the DAC datasheet from whic I could calculate the noise floor?

 

[flatulent]

Re: DAC noise floor

The total noise will be about 6N dB below full scale where N is the number of bits. It will be spread out from DC to half the update frequency.

 

[brmadhukar]

Re: DAC noise floor

Its is just one of the things that affects your noise floor. Nrmally you far out phase noise of the PLL will be more dominant ... taht's what I have usually seen.

6N gives the SNR for Nyquist ampling, normall DACs are over sampled, then you need to add the contribution due to oversampling.

BRM

 

[karote]

Re: DAC noise floor

Any source/reference how to calculate the affect of over sampling to the noise floor?


Thanks.

 

[FvM]

Re: DAC noise floor

I don't see that oversampling is implied with usual RF or video DAC.

To my opinion, spurious-free dynamic range (SFDR) would be a common measure to describe the noise floor. Apart from quantization noise that defines the theoretical noise minimum for an ideal DAC , nonlinearity is the major contribution.