17mm/22mm MTN-MAXlp - Low-Profile 1A-4A Programmable Buck Driver + 22mm MTN-MAX

Yeah osh can’t do it… But thermally, yeah can see your point it’s not for everyone… There’s a lot to the thermal side of things. Your dealing with this kind of heat I don’t think any amount of copper on the board can do the trick. You have to be able to conduct it to the pill. Look to your parts, they have to be capable also. Like the tiny has 125C rated chips and check the rest. The max is fine- I mean pushing 11 amps through the fet here. The trick to thermals is getting key parts to the ring and dumping it all into the pill… Guess doping would work too but I found it’s not needed.

The diode on mine at least is a size thing. I have to mill out some of the pill currently. The pfet is supposed to be more efficient too. I just don’t like the pfet is twice the resistance of the n. I might fit two in and see how that goes first. I’m a ways out myself.

I'll get the 22mm posted up and shared tomorrow. I've had it running in a few lights for a while. Here's one at ~6A, using an external inductor (deep pill) into an XM-L2 (the external inductor lowers overall resistance and definitely heat in the driver). It can also use a Coilcraft SMD inductor. The 22mm is single-sided, which makes building the driver a little less time consuming.

A 6 amp buck driver! I NEED one of those! Or maybe a few! :bigsmile:

Cool! What lights did you have it running in? Or what lights will it fit?

That one is in an X6 clone flashlight, but I've also put it in the Supfire L3. FYI, you can't run the newer XM-L2s at 6A. 5A or so is about it for most of them.

What is a X6 clone? I never heard of that before & with a 22mm driver, where are they available?

I bought them on closeout a while ago from a company here in the US, so I don't know where you can get them now. They are unmarked and have a pretty decent build quality.

5A is fine for my use - planning on driving a de-domed XP-G2 - on single cells, just can't get any amps out of them - Vf is way too high. So the 2 cell buck might be ideal.

Ok, and because you use your buck driver in it, i assume they are a X6 clone but with a 2 battery body. So are you going sell some of those in your shop soon?
They sound like an interesting candidate for a XHP build for example :wink:

No, I am not going to sell them. I can't get these anymore because they were a closeout item. I bought them to use as some test lights. I would use an L3 before these because it takes 26650s.

Yeah I know. I poofed a few on the Super Driver remember? But I have some oldy but goody xml2’ U2’s that work. What about the XPL’s, they should do fine?

Added the 22mm boards to the OP.

Ordered the 22's - now I just got to figure out parts.

Just an update on the 4-layer 17mm board: Ran it in my UF-1405 for about an hour straight on high at 5.5A with no step down and it didn't die, so it is probably about ready to be released. I'll probably clean up a few things on it then release it. Measuring the MAX and FET with a thermocouple it is obvious that the 4-layer board conducts the heat away from the critical components better than the 2-layer board.

So is this a new board just for higher current or a replacement for the 4A one too?

Sweet. How much more $ does the 4-layer board run at Osh? Other than the board, is it the same components that you have listed on mtn?

The 4-layer board is twice the price of the 2-layer. The components are almost the same, but there are two diodes instead of one, and an extra capacitor (which could be left blank if you only run it at around 3A-4A anyways).

Please excuse my ignorance. Richard, you said the 17mm 4-layer board did much better thermally. Are you going to make a 4-layer board for the 22mm design, or is it good enough at 2 layers? Are you going to be selling them at your store, and a parts kit as well? I’ve never built a driver before, so I don’t have any components lying around. Of course, I’d love to be able to buy the driver built and flashed with guppydrv, actually. I don’t know anything about OSHPark either. I just now registered with them and took a look around because I really want this 22mm buck driver!

Since these use attiny13 as an MCU I’m assuming that means that modes are made from PWM. I don’t know if that line of reasoning is valid (probably not, haha). Now that you’re selling these I want to know.

Also, what is the lowest low that the prebuilt 17mm design could do? If it indeed uses PWM, some info on limitations (frequency, duty cycle, etc.) for those of us interested in have custom modes programmed would be great. Thanks in advance, I know you’re a wicked busy guy!

One last thing, I know the voltage range for the prebuilt ones you’re selling spans 5-15V. What happens at say, 4.9V, if you programmed no LV warning? I ask because possibility of CR123a use is appealing.

Yes, the modes are PWM based on the buck IC, which can be up to 20 KHz on the input (We are running ~19KHz).

The moonlight level can be very low (The MAX16820 has a great dimming ratio).

At around 4.5V the buck IC will simply shut off. CR123s would only be useful in lower output scenarios since they are pretty current limited.