Compensation for a switching DC-DC converter

[jawlin2]

Hi all,

In most papers about switching DC-DC converters, the compensator is designed for CCM, and DCM is not taken into account. Could you explain it? Is it because the compensator for CCM can cover DCM? Thank you.

 

[edwintsu]

DCM is the same as CCM, except for the idle time.
It need no compensation at the idle time of DCM.

B/R
Edwin

 

[VVV]

DCM is in many cases just a consequence of light load operation. Under normal conditions, the P/S operates in CCM, so that is where you compensate it, although you need to verify stability at DCM.

For flybacks operating in CCM the loop will be much slower, to deal with the right-half-plane zero, so the slow loop will behave very well under DCM. In that sense you can say that the compensation will cover both CCM and DCM.