Why Ring Oscillator Based PLL?

[@abhiruplahiri1]

Great video CC. Another advantage of RO PLL could be to generate multiple clock phases--could be used for oversampling CDRs, perhaps in older standards.

[@circuitimage]

Hi Abhirup, than you so much for the extra comment, that's correct. Even though peopele often applied QVCO + PI to get the multiphase; the RO PLL is much easier. I'll mentioned that in another videio.

[@padapada503]

Hi, thank you for making such a informational video. One question. By QVCO, do you mean cross-coupled oscillator?@@circuitimage

[@circuitimage]

@@padapada503 Hi Pada, nice to meet you. Yes, but the cross-coupled oscillator could be just one of the QVCO. :)

[@srinivaskalwad]

Awesome 👍

[@circuitimage]

Thanks 🤗 Merry Christmas 🎄 to you and your family. 😊

[@JJ-lf9yp]

may I ask the difference for the ICO(current-controlled oscillator) and VCO, what are the disadvantage and advantage? Since I found referred information hardly, thanks.

[@JJ-lf9yp]

I guess the ICO structure for the back-to-back inverter has worse phase noise, but I don't know how to choose ICO or VCO, maybe you can give me some reference about these, thank you.

[@circuitimage]

@@JJ-lf9yp Hi JJ, nice to meet you and thank you so much for the excellent question, which I did not think through it carefully before. I don't know if I have the references since like you said that no one cared this or paid attention to this before. I'll make the next video to discuss about the difference and my circuit images. Thanks, CC.

[@JJ-lf9yp]

@@circuitimage very thank to you apply my question, the reference I study are the two following paper from ieee. ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1205683 class.ece.iastate.edu/djchen/ee507/Maneatis1.pdf my conclusion is: symmetric load VCO apply for low noise application, and CCO(ICO) apply for low power application.