Discontinuous Conduction Mode (Buck-Converter)

[Nissen, Søren Rune]

Why does DCM work the way it does?

Because it makes no sense (To me, obviously).

Not how it works. Why it works. The intuitive form, to me, would be that a lighter load would mean more time before the loop discharges, (due to tau = L/R) but apparently it's the other way around in a buck converter.

 

[berkeman]

Why does DCM work the way it does?

Because it makes no sense (To me, obviously).

Not how it works. Why it works. The intuitive form, to me, would be that a lighter load would mean more time before the loop discharges, (due to tau = L/R) but apparently it's the other way around in a buck converter.

DCM happens because the average output current is below half of the delta-I through the inductor. This TI application note describes it pretty well:

http://focus.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=SLVA057

.

 

[Nissen, Søren Rune]

Thank you, I'll see if I can make sense of this.