The 0.02mm² wire won’t work, 1.4A through that is a bit too much (50mA is the maximum current for that size). For now, maybe a 0.1Ohms 0805 resistor fits. Just to make sure it works (and it should put out around 300mA). I can order some resistors for you, no problem.
And with 20MOhm, you were driving an LED with around 1.5nA :laughing:
Was that a driver you powered on without shorting out two pads at first? Or have you tried the now working one without shorting the pads as well? Maybe the IC is toast because you tried it without shorting the pads at first.
I inspected it with magnification glass and it looked like the IC had no connection to the inductor on the side where it is hidden behind C1
I used very little paste on the outer pins of the IC to do no shorts there
OK reflowed it with a bit paste and now it works
this driver does spot on 1.41A, probably a lot variation on this 3 stacked sense resitors
Thank you for looking for an alternative, i’ll look into it. But for now, I managed to squeeze an ATTiny25v on there, so bistro-hd would be possible.
The springpad is now smaller, but it should work (6.4mm diameter or so). It was possible because the ATTiny has one side of pins without any connection, so I removed these solder connections. On the other side, I just left the gnd pin.
One problem with other MCUs is that you have to change a lot in the code to make it run, so I hope it works like it is now.
I hope the 25v in a qfn package is a rev E at mouser. This is required to be able to run bistro-hd.
But since it’s a driver where a lot of current could flow, I maybe won’t even solder a spring on there. A piece of brass/copper could also work, and needs no bypass.
Ok, I finally found my way to thread instead of just the backroom PM discussions (that there have been a bunch of). Subscribed.
FWIW I've worked up a "Fet only" (ie single channel) configuration of bistro-HD (will be in next release, soon). Been meaning to anyway (actually a few such configurations, switch, indicator, OTMS, etc). It took a little compromising to match ramps to TA modegroups, mostly because without a 7135 you can't go below 11mA (1/255 * 2.8A) so modes get cutoff, but I've been thinking of ways to get around it.
16bit PWM, if the converter can actually handle such output or true, 2nd channel, enable pin PWM reduction, but Schoki says it's hard to fit the trace. 11mA ain't too bad though. It's not really moon, but it's low.