I think a larger pad would do it. On Oct 19, 2017 12:35 AM, "Brian White" <bw.al...@gmail.com> wrote:
> That's exactly why I want to come up with a little saner way to pull up > PORT_EN. It's way too easy to just touch the wrong side of that resistor, > or something else in the area. It's begging to happen some percentage of > the time even if you know what the problem is and are careful. > > On Wed, Oct 18, 2017 at 8:05 PM, Brian Brindle <bbrin...@gmail.com> wrote: > >> Josh, >> >> I looked at one of the REX boards I had that didn't work. The regulator >> was getting hot on it and I had the same low resistance measurements on the >> VCC and ground. I know on this particular one I killed the CPLD by shorting >> the FTDI VCC and ground when jumping VCC to R3. >> >> Brian >> >> On Oct 18, 2017 7:22 PM, "Brian White" <bw.al...@gmail.com> wrote: >> >>> I guess if you're going to build over 60 of them it starts to matter. I >>> just figured if I'm going to go to this much effort it took just to build >>> one at all, that $1 wasn't even visible, but a built and in-use rex that >>> fails some day when it might have lived, is visible. So I went for the >>> better-ish versions of all parts. The factors for this are not the same as >>> for mass producing a clock that will sell in dollar stores. >>> >>> On Wed, Oct 18, 2017 at 6:39 PM, Stephen Adolph <twospru...@gmail.com> >>> wrote: >>> >>>> Commercial is fine.... >>>> >>>> >>>> On Wednesday, October 18, 2017, Josh Malone <josh.mal...@gmail.com> >>>> wrote: >>>> >>>>> Also, meant to ask: >>>>> >>>>> Brian's BOM includes the Industrial variant of the CPLD. The >>>>> commercial variant is almost $1 cheaper and seems well within >>>>> tolerance >>>>> >>>>> (voltage min is 3 instead of 2.7, temp is 0 - 70 C instead of 40 - 85 >>>>> °C) >>>>> >>>>> >>>>> Any reason not to sub this part in? >>>>> >>>>> -Josh >>>>> >>>>> On Wed, Oct 18, 2017 at 4:56 PM, Josh Malone <josh.mal...@gmail.com> >>>>> wrote: >>>>> > Thanks. I'm going to just order new parts and try again. >>>>> > >>>>> > On Wed, Oct 18, 2017 at 4:49 PM, Brian Brindle <bbrin...@gmail.com> >>>>> wrote: >>>>> >> 11.7k on 2 of mine. >>>>> >> >>>>> >> >>>>> >> On Oct 18, 2017 4:25 PM, "Stephen Adolph" <twospru...@gmail.com> >>>>> wrote: >>>>> >>> >>>>> >>> I can try to measure it later today for you. >>>>> >>> >>>>> >>> On Wed, Oct 18, 2017 at 4:24 PM, Stephen Adolph < >>>>> twospru...@gmail.com> >>>>> >>> wrote: >>>>> >>>> >>>>> >>>> either the chip is a dud, or you have soldered it down in the >>>>> wrong >>>>> >>>> orientation (which is kinda easy to do)... Do you have more >>>>> CPLDs? >>>>> >>>> >>>>> >>>> On Wed, Oct 18, 2017 at 4:22 PM, Josh Malone < >>>>> josh.mal...@gmail.com> >>>>> >>>> wrote: >>>>> >>>>> >>>>> >>>>> Thanks for the leads. >>>>> >>>>> >>>>> >>>>> I removed the CPLD and the resistance from 3v3 to gnd went to >>>>> open; >>>>> >>>>> repopulated it and it went to 3-ohms. Dunno what to try next. >>>>> Maybe >>>>> >>>>> put the same CPLD back on an original REX board >>>>> (non-castellated) and >>>>> >>>>> see what happens. But, I'd *really* love for someone to measure >>>>> the >>>>> >>>>> resistance on a known-good REX board and let me know what it >>>>> should >>>>> >>>>> be. Assuming the CPLD draws <= 1ma (datasheet says 17uA >>>>> standby), R >>>>> >>>>> should be over ~3k. >>>>> >>>>> >>>>> >>>>> -Josh >>>>> >>>> >>>>> >>>> >>>>> >>> >>>>> >> >>>>> >>>> >>> >
