Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Current ripple ratio and factor

Status
Not open for further replies.

Aether32

New Member
Can someone please explain the difference between Current Ripple Factor and Current Ripple Ratio?


Application Note AN4137, Design Guidelines for Off-line Flyback Converters Using Fairchild Power Switch (FPS).

Current Ripple Factor in this application note defines the Continious Current Mode like CRF=1
And Discontinous Current Mode are CRF<1

CRF=Current Ripple Factor= Krf


But the book Maniktala, Sanjaya (2006). Switching Power Supplies A to Z.

Defines a Current Ripple Ratio (prefix r) tells me that the Current Ripple Ratio below r=2 is a CCM and everything about r>2 is a DCM.

What is the difference between these two??
 
might just be how they define it.

there are actually 3 conduction modes possible: continuous, discontinuous, and critical. there is also inductor ripple vs capacitor ripple, both of which cause the component to heat up.

frankly some of that stuff annoys me since some like to do their own derivation using their own terminology and it takes almost as much derivation to get to the conclusion that it is or is not a variation of the same thing.

not having looked at the documents, it actually sounds like the ratio is peak-peak to average putting critical at 2, continuous below and discontinuous above. likewise CRF would then be peak to average.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top