How do you design these days?
in [Design]
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From: Falk Willberg on 31 Dec 2009 17:25 Joerg schrieb: > RogerN wrote: .... >> Is circuit design software and simulation good enough to go straight >> to a PC board? Or do you use surface mount to breadboard adapters? >> Do you still use a soldering Iron to solder or paste solder and an oven? >> > In the professional world (product design) we go straight from > simulation to schematic -> layout -> board fab -> assembly. No breadboards. How do you deal with "Locate capacitor as *close* *as* *possible* to the regulator output and ground pins"? (I know, you try to avoid using LDOs) How do you deal with incorrect/optimistic data sheets? I had more than one sensor (mostyl accelerometer/magnetometer), that behaved different from what the manufacturer hoped it would. Another problem is, that errata are written *after* the error was found. I prefer to have seen a design working as expected. But I am only a software guy, who knows where the soldering iron's hot end is, anyway ;-) >> I'm wanting to tinker with some circuits but some chips I'm interested >> in only comes in MSOP or other packages that look intimidating to >> attempt to solder. > Well, for hobbyists or one-off designs there is help but not very cheap: > > http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG That *is* cheap. > This is the variety they have but I don't know this shop, just meant as > an example: > > http://www.proto-advantage.com/store/index.php?cPath=2200 http://www.seeedstudio.com/depot/prototyping-with-smd-chips-stamp-bundle-pad2pad-p-137.html?cPath=64_33 But I prefer etching my PCBs to using breakout boards. Can save time. Guten Rutsch ins neue Jahr, Falk -- http://consult42.com/ http://falk-willberg.de/loetkunst.html
From: Jan Panteltje on 31 Dec 2009 17:30 On a sunny day (31 Dec 2009 14:12:03 -0500) it happened DJ Delorie <dj(a)delorie.com> wrote in <xnws039cvw.fsf(a)delorie.com>: > >My way is to use a solderless breadboard, but build up sub-circuits on >home-brew PCBs. So I've got a USB adapter, MCU adapter, ethernet >socket with discretes adapter, power supply boards, etc. Homebrew can >whip up a whole panel of breadboard adapters for SOT TSSOP CSP etc in >little time and at little cost. The breadboard is for interconnecting >the modules, adding pullup/pulldowns, etc. Once the circuits are >explored this way, it goes to a PCB fab as a single final board (no >production runs for me, just a hobby) and if it doesn't work I hack it >until it does. > >Here's an example of that process (scroll down to the breadboard >pics): http://www.delorie.com/electronics/alarmclock/ >http://www.delorie.com/electronics/alarmclock/20070723-proto.jpg One >project, nine adapter boards (ten when you include theftp://panteltje.com/pub/z80/graphics_card_top.jpg second OLED >connector), one breadboard. Real man use no PeeSeeBee: ftp://panteltje.com/pub/z80/graphics_card_top.jpg ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg :-)
From: Jan Panteltje on 31 Dec 2009 17:37 On a sunny day (Thu, 31 Dec 2009 12:18:44 -0800 (PST)) it happened "nuny(a)bid.nes" <alien8752(a)gmail.com> wrote in <06c2a0da-7756-4040-a798-7f917a50854c(a)a6g2000yqm.googlegroups.com>: > In the world of production though, that's the exception rather than >the rule IME. Even if the circuit does exactly what you first >daydreamed it could do without a single glitch, even if whoever etches >the board doesn't wire a pot backwards (I've had that happen), at some >point in the product development cycle somebody will alter a spec just >enough so that just enough redesign is required that your baby needs >Frankensteining. It might be you didn't include enough LEDs for the >required "ooh, shiney" level, the case design asshat^H^Hartists >decided the air vents are in the wrong places, it has to go "boop" >instead of "beep" when junior feeds it a PB&J, or whatever. > > SOMEBODY will find a reason it needs "fixing". > > > Mark L. Fergerson Yes I had that happen, where the specs changed after each council meeting.. Something to do with fire rules. But I did not have the board made until they stopped changing.
From: Joerg on 31 Dec 2009 17:48 Falk Willberg wrote: > Joerg schrieb: >> RogerN wrote: > > ... > >>> Is circuit design software and simulation good enough to go straight >>> to a PC board? Or do you use surface mount to breadboard adapters? >>> Do you still use a soldering Iron to solder or paste solder and an oven? >>> >> In the professional world (product design) we go straight from >> simulation to schematic -> layout -> board fab -> assembly. No breadboards. > > How do you deal with "Locate capacitor as *close* *as* *possible* to the > regulator output and ground pins"? (I know, you try to avoid using LDOs) > I grew up with RF-style design and EMC jobs so that really isn't a problem for me. The layouter I often use is also a bit on the older side and very experienced so I rarely have to tell him what needs special attention. Plus we are politically on the same wavelength which helps :-)) In my module specs there is always a section called "Layout Guidance". That has all the caution notes in there. And no, I do not use LDOs. > How do you deal with incorrect/optimistic data sheets? > I had more than one sensor (mostyl accelerometer/magnetometer), that > behaved different from what the manufacturer hoped it would. > > Another problem is, that errata are written *after* the error was found. > With reputable manufacturers that is rare but I had one of those happen recently. LT6700 series comparators. Turns out there's a bug on those in that the reference shoots way up after applying power and then settles after 500usec. In a nutshell, those things just don't work right until 500usec after power-up. The simulator doesn't show this and I think I was the first customer to find out. By sheer luck I had my design done in a way that I could muffle this. But other than that LTC is a great company, with excellent engineering support. > I prefer to have seen a design working as expected. > But I am only a software guy, who knows where the soldering iron's hot > end is, anyway ;-) > I am a hardware guy who sometimes finds a workaround solution in software and then says "Oh, it was just software" :-) >>> I'm wanting to tinker with some circuits but some chips I'm interested >>> in only comes in MSOP or other packages that look intimidating to >>> attempt to solder. >> Well, for hobbyists or one-off designs there is help but not very cheap: >> >> http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG > > That *is* cheap. > Yeah, in Euros ... I often design with chips like the LM3478. When you add a $2.50 adapter to each $1 chip it kind of adds up. I can get two bottles of top notch Porter for that. >> This is the variety they have but I don't know this shop, just meant as >> an example: >> >> http://www.proto-advantage.com/store/index.php?cPath=2200 > > http://www.seeedstudio.com/depot/prototyping-with-smd-chips-stamp-bundle-pad2pad-p-137.html?cPath=64_33 > Nice. Very smart design with the sliding scale QFP pattern. But being an analog guy I usually need TSSOP and MSOP. > But I prefer etching my PCBs to using breakout boards. Can save time. > > Guten Rutsch ins neue Jahr, Same to you. And careful with your Enfield motorcycle on the ice and snow. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 31 Dec 2009 17:54
Jan Panteltje wrote: > On a sunny day (31 Dec 2009 14:12:03 -0500) it happened DJ Delorie > <dj(a)delorie.com> wrote in <xnws039cvw.fsf(a)delorie.com>: > >> My way is to use a solderless breadboard, but build up sub-circuits on >> home-brew PCBs. So I've got a USB adapter, MCU adapter, ethernet >> socket with discretes adapter, power supply boards, etc. Homebrew can >> whip up a whole panel of breadboard adapters for SOT TSSOP CSP etc in >> little time and at little cost. The breadboard is for interconnecting >> the modules, adding pullup/pulldowns, etc. Once the circuits are >> explored this way, it goes to a PCB fab as a single final board (no >> production runs for me, just a hobby) and if it doesn't work I hack it >> until it does. >> >> Here's an example of that process (scroll down to the breadboard >> pics): http://www.delorie.com/electronics/alarmclock/ >> http://www.delorie.com/electronics/alarmclock/20070723-proto.jpg One >> project, nine adapter boards (ten when you include theftp://panteltje.com/pub/z80/graphics_card_top.jpg second OLED >> connector), one breadboard. > > Real man use no PeeSeeBee: > ftp://panteltje.com/pub/z80/graphics_card_top.jpg > ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg > :-) > <GASP> I think I am going to get sick ... -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |