So make your own then

Project closed.

More info please.
It’s boost driver for 1 cell and 6V led I guess?
Is it programmable with blf firmware?

Awesome……I guess?

We shall see.;))

If it’s as fun as the other drivers I got from you then count me in!

Quadrupel your pleasure

Quadrupel your fun

It's the right one

The Quadrupelmint gum

Is that a synchronous boost converter controlled by just an attiny? Pretty slick if you can pull it off. That gives me hope for a high power buck boost driver.

What kind of switching frequency do you expect?

Thanks for the schematic. I was wondering what F2 was being used for but still don’t see the need for it.

I believe the original driver switched at 300khz, it would be nice if that could be increased. Maybe replacing F1 with a Schottky diode might be easier than trying to figure out the band gap between F1 and the pfet. The band gap may need to change with load and temperature, and there could be some shoot through if the attiny gets too busy.

The attiny 1626 and 1627 are almost available. 20mhz clock speed and 12 bit adc would be nice for this application.

I was looking at a micro-driven switching controller a couple weeks ago but, with the chips I have available, couldn’t get a sufficiently high switching speed and decent resolution at the same time due to hardware PWM limitations. 6.8uH inductance probably helps with that; I wanted to stay under about 2uH to get high saturation and low DCR in a compact package for a 17mm driver. Slick use of the analog switch as a gate driver too.

So, ordered PCB and components. Coils same size 7x6.5mm, 3 values: 5.6, 6.8, 8.2uF and caps 22, 47 and 100uF for experimenting and tuning. :smiley:

How are they better than 1616?

The 1616 has a 10 bit adc but it may not matter if you are using an op amp. The little bit I have read about the two series claims very fast adc conversions and a more powerful cpu. Either one would be an improvement on the old 85.

My biggest concern is the attiny could be spending too much time on other tasks and not spending enough time on the boost converter. If this thing works and the switching speeds can be increased it opens the door to higher power versions and maybe buck boost as well.

Just took a closer look…I really like it. :slight_smile:
I wonder what kind of power can it deliver and at what efficiency.

It would be better in 20mm size and 2.5A @12V

I guess efficiency should be about 80-85% and power… maybe 20W?. Ordered few 20mm too.

To be honest I find the efficiency underwhelming…what makes it so much less efficient than say GXB172?

50mOhm series resistor and the rectifier drop, to start. Without a synchronous rectifier, conduction losses really pile up.

Hahahaha, what was that all about :smiley:

Yes, yes the best is synchronous rectification , but Ill be very happy with “only” 85% eficiency :smiley:

It's a (modified) commercial jingle for Wrigley's Doublemint gum.