Oh I’m so sorry, I forgot to to write it down and tell you! You have to solder bridge the middle pad to one of the outer ones. It must not be left open. Do NOT short out all 3 pads. There’s a small “E” of enable, and a “D” for disable power save mode. You can look at the datasheet to learn a bit more about the two modes.
It’s there for better efficiency at low currents. Since your running it at 1.4A, short the middle one with the “D” next to it (I think it could have a bit higher efficiency). You can enable it if you want, but I would only activate it if I’m under 150mA.
Edit: The 6mA is mostly because of the OpAmp quiescent current. It’s about 4.6mA typically.
I can troubleshoot them if you want, here are some pictures of the board and the schematic. Could you check all the traces? The pictures help you which pads are connected, check them for continuity. Could you make some photos of your boards as well? Link: https://imgur.com/a/315u7
If someone finds a mistake, please tell me.
Note: the one airwaire (coloured yellow) is there because Eagle won’t let me create polygons without something in it with the same signal. I placed a pad there on the bottom layer, so this one airwire can be ignored.
In the schematic, the pad on the input is called Bat-, it should be Bat+.
Was about to comment, R1 looks like sense resistor so I think 20m was 20 milliohm, 206 is 20 megaohm, so would make sense if no light with 20 meg in series with the emitter.
I currently don’t have, but I can order some, wanted to make a mouser order this weekend for the new MP3431 board anyway. If you want I can buy some 20mOhm resistors and send them to you.
Do you have higher resistor values in the milli ohm region, just to check if the board works?
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