LED driver circuit efficiency

[HackedFridgeMagnet]

The inductor wire is quire interesting, it's flat copper as opposed to round.

Yes I was looking at that.

Awesome looking component.

[SeanB]

Looks like the biggest power loss will be across the input fuse. Everything else is designed for lowest voltage drop at DC, and lowest loss in switching.

[digsys]

The inductor wire is quire interesting, it's flat copper as opposed to round.

Yes I was looking at that.
Awesome looking component.

We wind a lot of those type Inductors, awesome for high power, high frequency S/Mode. Flat and
thin is for skin effect. Bastids to wind though.

Added: On a side note, MANY of the first (and possibly current) MPPT designs run at 24-26KHz !!
It's how they get the last 1-2% efficiency. A lot of loss is in the slope, less transitions less loss.

[Federal Farmer]

I like the Allegro A6210. Minimal external components with an efficient topology, up to 46v supply and an integrated 3A MOSFET switch for not much more than the cost of the MOSFET in the OP's circuit. Like a lot of good chips only available in QFN so you really need a PCB.

^ Nice...
I am an ME by profession but have recently taken a liking to the EE side of things.
Do they make any type of surface mount proto boards or possibly an adaptor board for the A6210 footprint?
Didn't find anything on a quick Digi-Key search:
http://www.digikey.com/product-search/en/prototyping-products/adapter-breakout-boards/2360393/page/2?k=SURFBOARD



A bit simpler than what I was recently looking at:
http://www.intersil.com/en/products/end-market-specific/automotive-ics/led-backlight-drivers/ISL78100.html

[Rufus]

Do they make any type of surface mount proto boards or possibly an adaptor board for the A6210 footprint?

I doubt there are any suitable adapters. The package needs heat sinking to the PCB through its thermal pad and layout is fussy. You have very fast large current and voltage transitions on chip which also needs to sense LED current where a few mV of noise can upset it.

Allegro do an evaluation board, don't know how available or expensive it is. I think I have seen some people using the part for high power LED torches, search maybe you will find something.


edit: maybe you can get away with an adapter -

[lowimpedance]

[/quote]
The inductor design is quite interesting, it's flat copper.
[/quote]

Seen similar inductors at www.coilcraft.com  , (and many other styles etc) for those interested in diy.

[nukie]

It's called Helical Power Inductor. Epcos and Coilws makes them, I prefer Epcos.

[sarfata]

Hi,

I have designed a high-power LED driver around Linear Technology's LT3518. I posted the design files (it's all opensource) a while ago:
https://www.eevblog.com/forum/projects-designs-and-technical-stuff/looking-for-feedback-on-my-design-of-a-high-power-led-driver-9612/

I just got the PCB two days ago and soldered it. It works but I have not done any serious efficiency measurement yet (if you have suggestions on how to do it, I am interested...).

thomas