TPS548A20: Auto-Skip vs FCCM

Jaime C

Part Number: TPS548A20

Hi,

I am currently testing the capabilities of TPS548A20. I would like to further understand the differences between Auto-skip mode and FCCM mode and why Auto-skip is more efficient during light loads.

Thanks,

Jaime

over 8 years ago

0 JohnTucker over 8 years ago

TI__Guru**** 191445 points

In light load conditions the converter losses are dominated by switching losses. In FCCM mode, the converter continues to switch at the normal operating frequency so switching losses are not reduced. For Auto skipping mode, the effective switching frequency is reduced as the load is decreased, with a corresponding reduction in switching losses. That is the primary difference. There may be other considerations as well. I'll comment further later.

0 Jaime C over 8 years ago in reply to JohnTucker

TI__Intellectual 990 points

Thanks John!

0 Tony Wang over 8 years ago in reply to JohnTucker

Intellectual 310 points

Hi Jaime,
I have another question for you.
Could you please explain what are the means of "PGOOD in" and "PGOOD out" on page 6 of data sheet?

Thanks,

0 Tony Wang over 8 years ago in reply to Tony Wang

Intellectual 310 points

Hi John,
I have another question for you.
Could you please explain what are the means of "PGOOD in" and "PGOOD out" on page 6 of data sheet?

Thanks,

0 JohnTucker over 8 years ago in reply to Tony Wang

TI__Guru**** 191445 points

Obviously written by an ESL person. PGOOD in means PGOOD transitioning from "power not good" to "power is good". PGOOD out is transitioning from "power is good" to "power not good".

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TPS548A20: Auto-Skip vs FCCM