boost converter in crm mode

[ljy4468]

Hi all

I have some doubt about boost converter mode.

In PFC, it is common to use CRM (critical conduction mode) Boost converter with ZCD pin.
But in normal DC-DC boost switching regulator,there is no CRM mode converter in ADI, TI, MAXIM......
All converter is using internal oscillator to turn on MOSFET. (which means it can be used as DCM or CCM)

Why is that?
Is there some reason that switching regulator cannot use CRM mode????

 

[kalaianand]

Acheiving exact Critical conduction mode is not possible, provided your input voltage is not flutuating.
Yes we use boost converter for the power factor correction, it can be either CCM(continious conduction mode or CRM. Its not always to be in the CRM.