MOS Varactors | Oscillators 15 | MMIC 27

Here I describe the MOS varactor, focusing on intuition behind the different operating regions. I also describe how Inversion mode and Accumulation mode MOSCAPs function. Then I talk about accumulation mode MOSCAPs and how using a custom layout can make them a great varactor for RFIC. Lastly I present some Cadence simulations of the C-V curves. Useful references: Baker, R. Jacob. CMOS: circuit design, layout, and simulation. John Wiley & Sons, 2019. P. Andreani and S. Mattisson, "On the use of MOS varactors in RF VCOs," in IEEE Journal of Solid-State Circuits, vol. 35, no. 6, pp. 905-910, June 2000, doi: 10.1109/4.845194. RFIC Tape-out Playlist:    • Tape-out (RFIC/MMIC)