Output power recomended for LM5023 and LM5023

It is a very hard question to answer.
LM5023 operate at the boundary mode, it is more suitable for offline application. We would recommend less then 75W for application without PFC. Less than 150W for with the PFC circuit
LM5021 is for the fixed switching frequency Flyback. It goes similar power level as LM5023. However, for the low voltage such as 48V application, LM5021 is preferred.

Thank,

I have few question regarding ucc28630, it's same question, how is the max power(not peak power) recomend for this device.

My project 19V/6A without PFC universal input.

 

 

As Bing noted above, if the applications requires PFC when the input power goes above 75 W, then this will set the upper power limit capability of the Flyback power stage.

Some applications do not require PFC, even if the power is > 75 W. In these cases the Flyback can still be used, depending on system requirements.

 

For the UCC28630 specifically, it has a high current capability on the DRV pin, so it is suitable for driving pretty big MOSFETs with hgh gate charge. It has been used in applications with continuous power up to 125 W (peak power up to 250 W).

 

In reality, the upper power limit of the Flyback will be limited by other factors, like the size of the required bulk, the sixe of the transformer, the very high level of peak currents in transformer, diode rectifier, MOSFET, etc.

 

For your application, if the rated output is 19 V @ 6 A, is there any additional requirement for any peak or surge load above 6 A? The UCC28630 was designed for a tyoical applciation with 2:1 ratio of peak to average power, however other devices in the family (UCC28631/2/3) have different feature sets and can be used in applications with no peak power requirement, or a limited small peak requirement above nominal.

 

If you share more spec details, we can make more recommendations for your application.

 

Thanks,

Bernard