Jergosh
Newbie level 2
Ring oscillator
Hello,
I'm working on an assignment for my microelectronics course, which is to design ring oscillators with different number of inverters and compare their characteristics. Oscillators with 3 or more inverters work fine, but I can't seem to get a single inverter to oscillate of its own accord . Why is that? Is it just that the delay is too small for the inverter to 'notice'?
Also, I designed the inverter of which the oscillators are composed so that it has symmetric characteristics (i. e. equal low-high and high-low time delays as well as the output of 1/2 V_DD at input equal to 1/2 V_DD). However, when I measure the delays in oscillators they are different (e. g. 5 and 7 ps). I can't think of a reason for that either. Could someone please explain that as well?
I'm using Microwind 2 for the simulations.
TIA,
Greg
Hello,
I'm working on an assignment for my microelectronics course, which is to design ring oscillators with different number of inverters and compare their characteristics. Oscillators with 3 or more inverters work fine, but I can't seem to get a single inverter to oscillate of its own accord . Why is that? Is it just that the delay is too small for the inverter to 'notice'?
Also, I designed the inverter of which the oscillators are composed so that it has symmetric characteristics (i. e. equal low-high and high-low time delays as well as the output of 1/2 V_DD at input equal to 1/2 V_DD). However, when I measure the delays in oscillators they are different (e. g. 5 and 7 ps). I can't think of a reason for that either. Could someone please explain that as well?
I'm using Microwind 2 for the simulations.
TIA,
Greg