Trigger crossbar board shipped before CNY fab shutdown! Hoping it gets out of China before all of the FedEx staff leave for vacation.

Stencil is already here, parts should be coming in the next day or two and should arrive before the PCB.

This will be a fun design to bring up.

Got the QA report. I love this shop, they do this as standard not an extra-cost option.

@azonenberg Oh, single ended and differential impedance calculations are cool!

@doragasu Those aren't calculations they're actual as-manufactured measurements.

@doragasu And the board shop sends you the TDR test strips along with your order (pics from different order but same fab) so you can double check their measurements if you don't trust them.

They send you the cross section too. I love this place.

@azonenberg which place is it?

@daoistmonk https://www.multech-pcb.com/

@azonenberg What are their prices like?

@rgilton This was for five boards 165x121 mm, 10 layers ENIG with impedance control on 4 layers and filled ViP (full depth vias only, no microvias or blind/buried).

Mixed Taiwan Union TU872SLK for signal layers and Shengyi S1000-2M between power planes and their respective grounds.

@rgilton (prices in USD)

@azonenberg @rgilton as a hobbyist, it's interesting to see concrete costs of professional level development. I just got 3 copies of a prototype board made by @oshpark for $8, including shipping.

@jmorris @oshpark @rgilton This is actually "cheap". I was quoted something like $6.9K for an American fab to make a very similar specced board (but I think that one was only 8 layers not 10).

But when you add in the additional $1K-ish of components I'm putting on the board, the custom rackmount chassis, another $1K or so of custom semi rigid cable from PCB to front panel, etc. this is going to end up being one of my most expensive projects to date.

@azonenberg @oshpark @rgilton and this is why specialized technology is expensive, which I think many people don't understand

@jmorris @oshpark @rgilton Yep.

I mean, this is the FPGA I'm putting on the board. $249 @ qty 1. https://www.digikey.com/en/products/detail/amd/XC7K70T-2FBG484C/3641737

It has 31 of these connectors https://www.digikey.com/en/products/detail/amphenol-rf/925-197J-51PT/10712133 on it. At the qty 25 price break that's another $175.

The power supply is five of these https://www.digikey.com/en/products/detail/murata-power-solutions-inc/MYMGK00504ERSR/9748947 ($6.42 each) plus one beefier one for a higher current rail.

I could go on and on, but it adds up.

@jmorris @oshpark @rgilton So we're at the point that I don't even blink at the cost of throwing a STM32L031 on there just to manage sequencing of the dozen-odd power rails and resets for everything.

And the STM32H735 running the management interface is barely visible in the overall BOM cost either.