I have some questions on how the schmitt trigger works. Assuming we start with low Vin hence Vout is high. It means that M1 is ON thus the source of M2 is conducting Vdd hence M2 is On as well. However, M1 and M2 are off thus Vout=Vdd.

Now consider that Vin is increasing and is larger that Vthreshold for NMOS. It means M5 is conducting (does M1 and M2 stop to conduct instantly?).

The I am not sure what is happening. Can someone explaine me please?

Thank you!

cmos schmitt triger

  • 1
    \$\begingroup\$ Detailed analysis are provided here web.mit.edu/Magic/Public/papers/00260219.pdf and here core.ac.uk/download/pdf/234642998.pdf. \$\endgroup\$
    – devnull
    Apr 15, 2022 at 12:58
  • \$\begingroup\$ Thank you, great resources! \$\endgroup\$
    – makala
    Apr 16, 2022 at 8:47
  • \$\begingroup\$ I was reading the 2nd paper and the only part that I didn't understand was how increasing Vin decreases the source voltage of N2. Can you explain me please with some equations \$\endgroup\$
    – makala
    Apr 16, 2022 at 9:23


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