Differential Ring Oscillator

/ edmundsj
If you want to see more of these videos, or would like to say thanks for this one, the best way you can do that is by becoming a patron - see the link above :). And a huge thank you to all my existing patrons - you make these videos possible.
Here I go over the differential ring oscillator, an extension of the ring oscillator that allows us to only use two stages instead of three.
Hope you found this video helpful, please post in the comments below anything I can do to improve future videos, or suggestions you have for future videos.

[@mohammadkhorshidian2119]

Two-stage differential ring oscillator cannot oscillate due to the limited number of poles. Unless you do some modification inside the delay cell by adding a negative resistance in the drain (e.g. cross-coupled gm). Then with careful design, you can have oscillation.

[@xla6479]

how can the two-stage differential ring oscillator oscillate by adding a negative resistance in the drain????

[@mohammadkhorshidian2119]

@@xla6479 Look for "Design of CMOS Phase-Locked Loops" by Behzad Razavi. He explains it there.

[@xla6479]

@@mohammadkhorshidian2119 okay...😭

[@ofek2852]

what is the chance you are talking about small signal analysis? in large signal analysis, I don't see any limitation

[@denebvegaaltair1146]

Thank you so much! That was so clear and intuitive

[@JordanEdmundsEECS]

Glad it was helpful! What made it clear to you?

[@denebvegaaltair1146]

The overall circuit connections, waveforms, coloured direction arrows, and transistor schematics were all super helpful