I managed to make a 3D printed frame for the stencil. No where near mass production capable, I am just hoping to succeed with a few prototypes. Had some issues with my 3D printer, getting it to print straight. Now, all that really is left to do is just to do it. I must say I regret using those tiny Molex connectors. It always bites, when going with such small pitches.
Those nails line up the PCB and the stencil pretty good.
This is cool. I have not ordered stencils before but at work I have seen a handful. Usually they are a pretty large size, even if the board is small (this is with a domestic vendor in US). How did you get such a small stencil? Cut it yourself or does JLC provide a smaller stencil? Did you just make the case from your cad file of the board outline or did they provide some dimensions for the stencil that are different from your board?
You Can specify pretty much everything when ordering. I just asked for 2mm larger than PCB stencil. The stencil is not stretched out, so it is not ideal. It just lines up with corner holes and get pressed down / held in place by that two part frame.
The external LDO I just hot-air-reflowed is now working. But the strangest thing, I know the MCU has 5v on the REGIN pin, but 0.2V on the REG3V3 pin. Maybe it’s a fuse or register or something. The MCU is still virgin. Hmm
@runger did you try to burn/flash the STSpin32G4 already? How was the internal LDO behavior?
Edit: Maybe we have to provide 3.3v on REG3V3 while flashing first time, in order to set up the Internal LDO ?
Ahmmm, so I should have tied the external LDO EN pin (powering VDDA) to the MCU.
During power-up and power-down, the following power sequence is required:
• When VDD is below 1 V, then VDDA supply must remain below VDD + 300 mV
• When VDD is above 1 V, all power supplies became independent.
Lets say it can drive 48V led Strings w. 5 amp on each bridge. 5 amp x 48 = 240W x 4 = 960W LED GROWTH LIGHT ( 7 amp is 1.078mW on the shunt rated for 7W). If you take the three level stack into account, it essentially is a 12 layer PCB