dc-dc converter switching frequency , bandwidth and crossover frequency

[areebaa]

hi,
in case of dc-dc converters what is the main difference between switching freq , bandwidth and cross over frequency.
is the cross over frequency is almost equal to bandwidth ?
thanks

 

[schmitt trigger]

the only requirement for the switching frequency, is to be higher than your crossover frequency.

Bandwidth and crossover frequency are interchangeable descriptions.

 

[areebaa]

so, if the switching freq is 1MHz and cross over freq is 50kHz , this means that the feedback will ignore the changes over 50kHz?

 

[mtwieg]

Crossover frequency is just the frequency at which the total loop gain is 0dB. I don't think "bandwidth" has a specific meaning with regards to smps. Could possibly refer to the -3dB point of the converter's transfer function, or the -3dB point of the closed loop transfer function.

 

[schmitt trigger]

so, if the switching freq is 1MHz and cross over freq is 50kHz , this means that the feedback will ignore the changes over 50kHz?

Ignore is not the proper word to describe it.
Rather the gain has fallen below 0 db.

No gain: no correction capabilities.