• 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.

Boundary conduction mdoe LED drivers

Status
Not open for further replies.

Flyback

Well-Known Member
Hi,
Why do virtually all offline LED driver IC’s involve the Boundary Conduction Mode (BCM) principle? (AKA critical conduction mode) It certainly has advantages, but the one huge disadvantage is that you can’t dim them down to low light levels without the switching frequency getting ridiculously high. It’s possible to avoid this by making them with a minimum off time, but virtually none of these BCM led dirver chips have this facility.

So why is this?

LED driver datasheet (NCL30002)
https://www.onsemi.com/pub/Collateral/NCL30002-D.PDF
 

tomizett

Active Member
Off the top of my head, possibly because the average current is always proportional to the peak current, so you can just program the peak (trip) current and there is no need for an average-current feedback loop? Other then that, no idea!
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top