Frequency domain DAC output

Hi Topspin ,

  is currently checking this query and will get back to you soon.

Br,

Den

hi dendalisay 

any news on this?

Hi dendalisay and  

Can you take a look at my post?

Hi Topspin 

I apologize for missing your question. The harmonics come from the inherent errors of the DAC. As mentioned in the guide they can be static or dynamic in nature. The first page of the document gives details on the static or DC errors such as INL, DNL and, offset and gain, while the dynamic components were shown in the time domain DAC Output plot. 

In terms of the effect of resolution, my opinion here is that these would contribute to the quantization error due to the finite steps that you can produce in real life. Feel free to reach out if you have more questions. I'll share this with the rest of the team and the experts might be able to shed more light on your question. 

Best regards,

Ian

The harmonics come from four different sources:

• Quantization noise: when the input signal is a sinewave, quantization noise is correlated to the signal. The distribution of this noise depends on the fs/ft ratio. Increasing fs or increasing the resolution reduces the amplitude of quantization noise, but there is still a noticeable variation with the mentioned ratio. This noise can be easily seen in numerical simulation.
• D/A glitch: if the D/A glitch occurs at periodic codes, it gets modulated by the input signal causing harmonics at multiples of the fundamental. To reduce the contribution of this effect, a DAC with a low D/A glitch is recommended, such as the AD3542R or AD3552R.
• INL: for low frequency sinusoids at full scale, INL is an important contributor to harmonic distortion. A DAC with a noise-like INL will produce less distortion than a DAC with an S-shapes or bow-shaped INL.
• Analog distortion in the amplifier. Usually the least important contribution, but some amplifiers can have a noticeable effect.