These are really tiny. That's an 0603 resistor on the right
This is the smallest of the EPC parts. Most are for power switchers, but this one has low enough capacitances that it might be useful in signal apps. 7 pF Cin is OK, but the 0.02 pF Cdg is something that no mosfet can touch.
Has anyone used these? I might try a PCB prototype, but it looks tricky.
I wish they would offer these parts in a real package.
Den onsdag den 10. januar 2018 kl. 23.57.26 UTC+1 skrev John Larkin:
it is only four pins, scratch an X (or T two pads a source) on some FR4 and use a bit of paste and hot air
If it's any comfort I have to design three boards right now and on one of them a 0402 resistors is actually like a big component.
Or do a quick layout of "surf board" batches, have them produced at one of the quick turn places and have them scored or milled so they can be cracked off when needed. Then plop that on copperclad as a "now larger FET".
I'm faced with all the Avago phemts going EOL, so I plan to lay out a
4-layer PCB with maybe 10 different test circuits, and this little GaN thing will be on several. I think this is out of dremel territory. I don't want to solder it by hand.EPC has eval boards, but not for this one. The data sheet is pretty good, so I'll skip fiddling and just go to some actual circuits.
Of course, this is sole-sourced too. It's under 50 cents, so we could at least make a giant lifetime buy.
This might be the time to splurge and invest into laser structuring.
As a side effect then you can also engrave trophies, fancy placards, name tags, jewelry and so on. Just make sure the fumes get vented properly.
you can get a crap load of proper pcbs made for the price of the laser gadget
Yes. However, then the PCBs won't be ready and on your desk in two minutes. Also, that laser would the one of the ultimate man cave toys. If I had the space ...
My other dream would be a computer-controlled mini-mill but same problem, not enough space. We just sold our Hammond organ so I could use that space in the living room entry but afraid my wife would object.
Just saw this:
it is far to flimsy, you will be sorely disappointed
something like this is bit better,
I build my own from, bit and pieces on ebay etc.
space can't be a problem, it takes less space than one of your boat anchors ;)
We had one of those PCB milling rigs and got rid of it.
I can lay out a test board and get a half dozen nice 4-layer boards, with planes and plated vias and solder masks and silkscreen, in a week or less. I can find something else to amuse me while I wait for the boards.
I do this now and then. I walk around engineering and see if anybody else wants an experiment or an adapter or something, and throw that on.
These Z-series proto boards are archived and test results are documented for posterity.
I don't think one of those LPKF things will make a board in two minutes!
Laser?
We can mill little single-sided boards on our Tormach, but seldom do.
Make another pcb with various parts and connectors and such. for ~$100* a pcb is ~1 hour of my time, (well I only get a fraction of that dollar, but that's what I figure my cost.)
George H.
*3@$33 ea, plus S/H...
I know nothing of pcb milling. The machinist's (at university) would not let us get fiberglass and other gritty stuff anywhere near their mill beds.
George H.
What ship time? (Is that the ExpressPCB or Advanced proto pricing? I forget.)
The mid-cheap Chinese fabs do 2 week turn, qty 10, some inches square, under $50. Smaller boards as cheap as $10.
All depends on how long you can wait, of course.
Making PCBs for one-offs is usually a false economy as it's easy to forget how much time it takes (heck, you might even /enjoy/ it :^) ) to create the layout (and, for milled boards, the time to convert gerber to g-code, and set up and run it). You spend as much time scratching up some copper clad, albeit at qty 1, but that's all you need to check an idea.
(Kind of like the open source fallacy: the people who support it the strongest, rationalize their time spent as a fun hobby (or proselytizing for that matter). It feels good, but then they wonder why these things aren't more popular. Well..)
Tim
True. I found this STP4LN80K5, which is only a "little" bigger TO220. it has input capacitance 122pF when GaN has 700pF and SiC 260pF.
Advanced circuits. (4pcb.com) 2-layer. It's $150 if you want to panelize the pcb. (There's some bare bones version w/o the solder mask or silk screen but I've never tried that. And sure there's your time to layout the pcb.
Delivery is about 1-week from the order, (maybe a bit more) that's UPS ground.
Right, If I really want to try something right away, I'll air wire over copper clad.
George H.
That is the best option but I usually do not have that extra week. Which is also why I rarely use eval boards.
Ok, maybe three minutes :-)
I didn't mean a board the size of a dinner plate, more a small experiment board of a few square inches with a dozen cuts of so. But if you have a Tormach you'd be all set anyhow,
Yes, you'd pretty much have to dedicate this machine to that job because it'll get dusted up. Best not to use an expensive rig for that.
Being too fussy about machines may be ok in an academic setting but in regular business that can cost. Once when we made a MEMS sensor a provider said "No, we won't allow this chemical in our process" and "No, that one neither". So we walked. They lost out on a fat five-digit chunk of revenue.
Sure I just wonder how long till the milling machine gets cruddy and has to have maintenance or replacement. I think KRW (Keith) said they had one at his work place, or previous, maybe he can comment on durability.
George H.
Those odd flip-chip EPC FETs have astonishingly low inductance. I've seen them switch 30A in under a nanosecond from a 40V rail.
Cheers
Phil Hobbs
I got a bunch of EPCs to evaluate. They are tiny but my people say they can assemble them. The bummer, relative to phemts, is that they need a few volts of gate drive. The e-phemts could be driven with 800 mV, straight from ECL.
Likely it was GaN that killed the phemts.
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