FEDEVEL
Platform forum

V3rn3r , 01-07-2019, 10:24 AM

Hi Folks!!!

I've encountered with one interesting thing that I couldn't even imagine).
I want to make a sort of router based on MT7621A IC. But it ain't easy as it might sound. I barely find out a datasheet and I didn't find an official reference design and any kind of layout documentation is top secret information as I understood. I've written 5 or 6 letters on official Mediatek email but was unlucky so I got no replies. So I tried to use their forum but the communication of support team is very slow.

Luckily I found some opensource project named WiTi and now I'm using schematics from them as a reference, but this documentation doesn't drop much light on issues I have.

So, I wanted to ask experienced designers about such problems with documentation, chips support, and all documentation search.
BTW. I didn't found MT7621 nor on mouser nor on digikey, only local China market suppliers have this ICs in stock.

mairomaster , 01-08-2019, 01:56 AM

It's actually a fairly common problem with niche/specialized chips. Normally in such case if you don't work with the manufacturer to get a support, you just don't have sufficient documentation.

robertferanec , 01-08-2019, 02:41 AM

It's very common. I actually try to avoid using chip support - in 95% they quote a text from datasheet which I have already read a week ago. You need to be very important to the company to be able to get a good support. PS: I have a rule - if it is not possible to buy a chip from Digikey / Mouser / Farnell, do not use it in design.

V3rn3r , 01-08-2019, 11:55 PM

Many thanks for your replies.
It took me some time to understand the way of thought of this way vendors.
So here is my opinion:
I think that poor documentation and poor distribution of some chip manufacturers are mostly related to the aim of manufacturers to make "end products" their own, and distribution needed just for maintenance and so on.

One more question for that topic:
Had anyone experience in communicating with Chinese PCBs forums like http://bbs.ntpcb.com or something like this? I found they put for discussion and education a lot of schematics and all other related documentation.

robertferanec , 01-09-2019, 02:45 AM

- in general, I do not use chips from small manufacturers. But even big manufacturers very often cut of chips from production or have 4 months of delivery time. Documentation quality depends on standards of the company - usually they have all documentation really good or they have really poor documentation. Usually, companies from china or smaller manufacturers do not have as good documentation as big companies, but even big companies may have sometimes confusing documentation (a lot of documents spread around). Best documentation I have seen is from companies like Intel, AMD, etc.

I have not used Chinese forums, can't comment on this.

V3rn3r , 01-13-2019, 06:34 AM

Many thanks! For your replies.
Now I got my opinion on the project I'm going to make.
Moving from Mediatek to NXP. Found out the processor that might be used in my tasks