Does crossover frequency correspond to CCM calculation?
Posted by: treez
on
Hello,
I have just done a Topswitch Flyback design in PI Expert for
Vout = 25v
Iout = 1.3A
Fsw= 66khz
Adapter
TL431 feedback
The PI Expert made it a mostly DCM design, but it does go into CCM at the minimum Vdc input.
The PI Expert gives a value of phase margin = 50 degrees
Also PI Expert gave the crossover frequency as 1218 hertz
Which value of Vin do these feedback loop calculations correspond?
Do they correspond to the Minimum Vdc input voltage of 86.3Vdc?
Do the given values of phase margin and crossover frequency come from a CCM calculation, or a DCM calculation.? (note that the PI Expert design would be in CCM at the minimum stated DC input voltage of 86.3Vdc.)
Which value of Vin do these feedback loop calculations correspond? Minimum DC voltage (VMIN)
Do they correspond to the Minimum Vdc input voltage of 86.3Vdc? Yes
Do the given values of phase margin and crossover frequency come from a CCM calculation, or a DCM calculation.? (note that the PI Expert design would be in CCM at the minimum stated DC input voltage of 86.3Vdc.) The mode of operation depends on KP. For a KP<1, the design is CCM and DCM otherwise. The frequency response plot changes its shape based on KP.