DCDCv9-3r1
This release fixes small clearance issues:
- Increased the spacing below the gate driver from 0.3 mm to 0.6 mm, as the IPC 2221 does not provide for spacing between the inner and outer layers.
- The same applies to the trace below the resonant capacitors (also moved capacitors to the left).
- R54 Pad 1 footprint distance has been increased from 0.2 mm to 1.2 mm. Simulations have shown that this pad can reach up to 400 V to GND, so that at least 0.8 mm is required. However, it was increased to 1.2 mm to be safe in the event of a voltage surge.
Q&A
Q: I've already ordered PCBs for the DCDCv9-3r, should I order new ones?
A: The fixed issues 1. and 2. are afaik best practices, but there might be little to no change in likelihood of a failure in this area. For issue 3. the resistor R54 does limit the current to such a small value, that even in an event of a breakdown just 36 mW will dissapear, which would be no issue for the resistor. However, the additional current sensing might not work anymore and lead to overload of the SR-MOSFETs when large uncharged capacitors are connected. The overcurrent protection would then rely soley on F1 - which is permittable. In doubt, remove Pad 1 of R54 on the PCB and connect R54 to C39 directly.
I would give those fixes a re-order rating of 3 out of 5. If you are willing to make the R54 fix I would rate it just 1.5 out of 5.