venn_ng
Member level 5
Ring oscillator Q factor
Let's take an N stage ring oscillator.
If the Q factor is defined as,
Q=2pi * maximum energy stored/ energy dissipated per cycle
since the max energy stored in the cap is CV2/2 and energy lost in the resistors as heat every cycle is CV2, I get Q < pi ~ 3.14. But I read that ring oscillators have Q ~ pi/2 as N-> ∞.
What's wrong here? (is it something to do with the harmonics?) Does it depend on number of stages in the ring, as I don't see an obvious dependence on 'N' since for each cycle, all inverters store and dissipate the amount described before.
Let's take an N stage ring oscillator.
If the Q factor is defined as,
Q=2pi * maximum energy stored/ energy dissipated per cycle
since the max energy stored in the cap is CV2/2 and energy lost in the resistors as heat every cycle is CV2, I get Q < pi ~ 3.14. But I read that ring oscillators have Q ~ pi/2 as N-> ∞.
What's wrong here? (is it something to do with the harmonics?) Does it depend on number of stages in the ring, as I don't see an obvious dependence on 'N' since for each cycle, all inverters store and dissipate the amount described before.