I want to design differential ring oscillator. I want to know how to determine the aspect ratio of all nmos and pmos transistor of the delay cell (the design procedure ) .
Thanks in advance
It depends on the mobility of the transistors you are using. Ideally, you want equal rise/falling time of the output signal, so you'll be adjusting the size accordingly
i think i had found the solution but i didn't try it on a simulator . first step is to determine the gain of the delay cell , the gain depend on the number of stages of the oscillator to ensure barkhausen criteria . by knowing the gain and specified power consumption we can determine the aspect ratio of each transistor .
it is very important to know the mobility and thickness of sio2 Tox of the technology during the desgin procedure to get accurate results .
Well done Mr. Ahmed. When setting the pole to -1, you will use a formula with gm inside to determine the size of your first transistor.
The delay cell transistor sizes have to be fine tuned as it will effect the beauty of the output oscillating signal. I just use a 1x, 2x, 4x size to start with and fine tune slowly from there.
What technology are you using sir?
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