PFC

yhhhy

PFC [Copy link]

Is the CRM model obsolete?

led2015

I don't know why, I can't open JPG

soso

led2015 posted on 2023-5-16 21:09 I don’t know why, I can’t open the JPG

Now look, can you open it?

不亦心

The CRM model is the king in small and medium power applications. Has it been eliminated by you?

yhhhy

Bu Yixin published on 2023-5-18 00:21 The CRM model is the king in small and medium-power applications. Have you eliminated it?

Boss, do you use DCM mode a lot?

qwqwqw2088

The critical CRM resonant frequency is not fixed either. You need to constantly adjust the output voltage.

DCM should be used mostly for small power, within 100W. In theory, a small transformer can be used to reduce the size of the power supply.

不亦心

yhhhy posted on 2023-5-18 08:50 Boss, is the DCM model used a lot?

There should not be many applications of pure DCM. In the past few years, BCM single-stage PFC was more common in LED power supplies, but it is not clear now.

Current PFC controllers are developing towards multi-mode, including DCM, CRM, and CCM.

There are many CRMs in small and medium power, and the distinction between CRM and DCM is not so clear. CRM is not locked at the first valley bottom, but can be locked at the Nth valley bottom according to the working conditions. This is DCM, but the traditional DCM does not lock the valley bottom, while CRM locks the valley bottom. When the frequency exceeds the controller range, the CRM mode will also switch to DCM and no longer lock the valley bottom.