grizedale
Advanced Member level 3
why, in smps feedback loop, ....why does the overall closed loop gain have to be going down at -20dB per decade at the crossover frequency?
I would have thought -40dB would have been ok too?
Surely, as long as the closed loop gain is <1 for frequencies above the crossover frequency then its fine.........(as long as the phase is always >45 degrees above the crossover frequency too.)
so why does the slope of the closed loop have to be going down with a gradient of exactly -20dB per decade at the crossover frequency?
I would have thought -40dB would have been ok too?
Surely, as long as the closed loop gain is <1 for frequencies above the crossover frequency then its fine.........(as long as the phase is always >45 degrees above the crossover frequency too.)
so why does the slope of the closed loop have to be going down with a gradient of exactly -20dB per decade at the crossover frequency?