DAC test input signal doubt

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cying

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In the datasheet of every dac there are SFDR value . For example for 1Meg input & 100Meg clk the SFDR is 75db.
As you know , the digital sin wave is the proper signal source for SFDR test.
My doubt is the 1Meg frequency is the digital frequency or the sin wave frequency.

If it is the digital frequency , then which is the sin wave frequency ?
And the digital frequency for 1Meg sin wave frequency?
 

there is no "digital" or "sine" frequency. There is signal frequency and data rate speed. For example You can supply DAC with 10 milion bytes per second and have signal frequency form DC to 5 MHz. 5Mhz is maximum because of the Nyquist rule. Look at th picture: Signal frequency is 7.81MHz and data rate is 25MSample per second. Signal frequency is encoded in sample's value.

To test your DAC you must supply to him 100 milion samples per second. Value of samples must aproximate sine signal with frequency 1MHz. If you keep this requirements, you will measure SFDR of 75dB as is stated in datasheet. You must consider that this value is the best wich can be obtained for that IC. All manifatcurers show their best, not typical, og worst case results ...
 

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