Ring oscillator circuit with RC-network

VDD = 2V and Vin can be either be 0 V (logic 0) or VDD (logic 1). Switching time of a transistor in the circuit is about 1 us. The transistor threshold voltage is 1 V (nmos) and -1 V (pmos).

Assume that R = 10k and C = 1 nF in the circuit. Plot a graph of v (t) as a function of t in an interval of about 20 us. Describe why v (t) behaves the way it does. The graph should show an approximate behavior and need not be exact. What happens if you decrease or increase the value of R?

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