Tiny 20mm BLDC Driver

Meet TINY, my latest design.

Max 24v / 10A (theoretically 60A however I very strongly doubt you can pull more than 10A before you melt the solder)

And Tiny+ which is 25x30mm with discrete MOSFETs, drivers and complete current sense!

I will be testing this week, let you know if they explode or actually work…

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Are you using KNG3703A ?

Yes, I paired it with DGD05473FN and INA199 bi-opamp.

If the experiment is successful I’ll post the schematics public.

Update: both PCBs appear short-circuited when SMD-ed. I reviewed them under high magnification and the footprints are poorly soldered and one of the MOSFETs sides were even ground by the PCB router (the CNC cutter that cuts out the PCB boards after soldering). My guess is that JLC’s capabilities were really pushed at that high integration and small footprints. I will go back to the design and try to rearrange them, however, I have the suspicion that JLC cannot SMD properly these types of MOSFETs. Not giving up yet. It is also possible that may may be if I run a higher batch number of PCBs at least one will come out well soldered. This is a proof-of-concept anyway. When I review the bare PCB it’s perfect, so the PCB itself has no issues. It’s the SMD process. The obvious option is to go for larger MOSFEts with coarser footprints.

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I would buy if it was on sale…

I’d buy one, too, if it were available to begin with. I’m doing this not for the love of burning my fingers soldering. I’m sure, once the design is finalized, and a large batch is ordered, the cost could be brought down to about $10/board. I’m not in the business of selling those, however, I’ll post the design and if people are interested, they could pool together and order a larger batch. The small one (2x2cm) in small batch of 10 would cost about $5/board out of the factory, however, it will probably cost double with testing, taxes and shipment, and eventual replacement of faulty ones. so I’m thinking $10/retail with $0 profit, for the sport. If you add current sense and some basic protection, may be double that? If you add an MCU for a soup-to-nuts board, you are probably looking at $30/board.

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@Valentine

Nice relatively tiny footprint for 10A.

Hopefully it becomes standard midium power SimpleFOC board.

Thanks for sharing.

Well, I just re-ordered the 2x2cm with a little bit larger spaces. May be this time the SMD will succeed. Call me either stupid or stubborn. Not giving up. Next I’ll review the small current sense one. In fact, JLC called me and told me the fist design was having manufacturing problems, I guess I never checked my messages, so apparently they were aware that it’s borderline impossible. We’ll see.

Valentine, im very interested your design. Now i need compact driver for my robot. Now im using drv8302 big (100*70) pcb. But my current max 10A and i no need all power of my current board. Please notice if you board will working good. Thank you

I’ll let you know. Are you using a particular MCU or you will use an MCU outside of the driver board?
Do you have the exact size/space limitations, as well as voltage and current? Motor specifications?

Also, there are small commercial drivers with an MCU, discussed here on the board, such as the STMs ESC board.

I’ve seen other efforts too, such as this one

So. My current setup is this board and outside mcu.
Im using this for balancing robot. It works well but i want to make it more compact.
Im using drones motor 14-24v with 180-330kv. 5010 size
Important condition is outside encoders in view of the design

https://aliexpress.ru/item/4000126430773.html?algo_expid=a8c78ba9-db8f-4369-8d14-de5d906bd553-0&algo_pvid=a8c78ba9-db8f-4369-8d14-de5d906bd553&sku_id=10000000365339084&spm=a2g0o.search.0.0.467f3298l6R27p)

That’s a 20 to 30A motor. I doubt the tiny driver can support this current due to the PCB board.

Problem is the SMD MOSFETs need to drain and source from the bottom which for small 3x3mm footprint requires vias and the JLC vias are un-plugged, they don’t support plugged vias so max current per via is 2A, at most 4 vias, you could probably pull 10A and then the solder will melt. At 30A you will literally smoke the board. The mosfets probably be OK if you heat-sink them but you cannot drain this current from the copper. JLC doesn’t support 2oz copper SMD, it’s either/or — either 2oz bare board or 1oz SMD board. Stupid. PCBWay does support but it makes your board insanely expensive.The way I’m designing it, I put the vias inder the solder mask so I’m cheating a little, because the machine will squeeze some solder inside the vias to partially plug it. JLC really doesn’t like that, but so far they haven’t really rejected any of my designs :wink:

I could make the small driver 4-layer with partially plugged vias, that may work better but you’ll need a heatsink, absolutely.

I have a similar motor and when I get the new board I’ll try to pull high current. Problem is, you MUST use a heatsink which will increase your size.

Now i think to buy SimplefocPowerShield from Ali and test it. May be it will suitable for me

Oh man, I’m so sorry to hear that!!! They look so cool!

I know you like JLCPCB, and for good reason, but for this specific case I can say that both PCBWay and Eurocircuits can both make these boards with tented vias and no routing errors. PCBWay has made boards as small as 14x8mm for me, no problems…

It’s part of the game. I was not really expecting to work from the first time. These designs go through at least five to six revisions before a viable solution is found. I had a chat recently with someone who did the original iPhone design, their PCB went through 10000 revisions before they called it good for production. Some of the features were not even possible at the time, so they ended up designing an entirely new production process and tools. I ain’t no Apple so a few revisions for me should be an acceptable failure rate :wink:.

Very, very expensive. And their sourcing process is really heavy, and hard to communicate. I can turn around three JLC revisions by the time I get even one from PCBWay. I look at them only if I need to produce something which is a complete, final design for production. The one you show me above, no way JLC can make that.

I’m quite confident that a small solution is possible, just have to get enough critical mass.

Got the second variation.

Update. It worked this time! My test motor turns.

This time I made 5 pieces, and picked the cleanest. It kind of works, but one of the mosfets phases gives a weird output, I need to check all 5 PCBs to see if this is an issue with the way I designed the PCB or just that one mosfet was unlucky. Not clear if this is an SMD process error, mosfet, or PCB design at that time. However, in my books, this is a great advancement. So far that PCB is the tiniest BLDC controller I’ve seen. I’ll continue testing, may be post some videos.

The good news is, that MOSFET driver doesn’t suffer from the high frequency inefficiency we had with some other integrated single phase drivers. I ran it on stock Arduino Nano at 12V, 32kHz, no issues at all.

Merry Christmas to all.

Cheers,
Valentine

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Valentine nice progect
Can u share plz schematics?
I want use design for reference in my progect.
Tiny driver is actual beacause TI out of stock 8316 driver version :confused:
Sry for english i try to improve it XD

@Andrey_Sabadash

I will post the driver, however, three things.

  1. The MOSFET is discontinued. This is an experimental product by this company and is not for new designs. This means, it will not be produced anymore.

  2. The MOSFETs cross-talk. In a 3-phase configuration, somehow the mosfets cross-conduct. I suspect the diodes have a problem.

  3. JLC could not properly SMD the mosfets, may be that’s one of the reasons they cross-conduct.

The conlulsion is, this was too good to be true. I’ll post the design as an educational aid how to build a driver like that, but you will need other mosfets.

Cheers,
Valentine

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This is the project. You will need to fabricate yourself, and have some basic knowledge of replacing components if the ones I used are out of stock. As I said, it’s not really a good idea but since you asked.

https://oshwlab.com/cost.co/17112021_up9636pqmy_dev

Good luck.

Cheers,
Valentine

PS I also cut a corner, there are no output capacitor filters since its experimental.

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Hello Valentine, Is the TINY+ working well

Havent had chance to test yet.