| ??? 07/16/09 07:34 Read: times |
#167393 - so... Responding to: ???'s previous message |
Kai Klaas said:
Yes, you can connect the GND islands on top and bottom layers to the common ground plane via vias. One more qustion - I saw a pcb layout where a lot of small ground vias were close to edge of the board, not in parallel. It looked like a riveting. Is there any special meaning of this? Kai Klaas said:
Unfortunately I have no schematic of your circuit, so I can only guess what's the circuit is doing. I guess that GND of switcher is to be connected to the common ground? Then, do it directly, without a ferrite bead, and do it best at the ground pin of output cap. Make a connection of your local (the switcher's!) ground plane to the common ground plane only near the ground pin of output cap of switcher. Yes, the switcher's gnd is connected to the common gnd. It is realized by the FB in my case. I am going to remove it and connect switcher's gnd directly as you suggest. And what about Vcc behind the output cap? There is also FB in my schematic. Should I remove it too or not? Kai Klaas said:
Connect the input of switcher to the rest of circuit by a ferrite bead, so that in combination with input cap an input low pass filter is formed. But keep the input cap on the switcher's ground plane. My device could be powered from 9 - 15 V AC. So there is a rectifier. Should I place the FB(s) between the rectifier and the input cap to keep the input cap on the switcher's ground plane? Should I place it(them) at both of the poles of the rectifier or only at +? Thank you very much... |
| Topic | Author | Date |
| PCB design - ground plate... | 01/01/70 00:00 | |
| excuse... | 01/01/70 00:00 | |
| You can use a local ground plane, but... | 01/01/70 00:00 | |
| So, if I understand it well... | 01/01/70 00:00 | |
| Yes, of course, but... | 01/01/70 00:00 | |
| Yes, but... | 01/01/70 00:00 | |
| No overlap | 01/01/70 00:00 | |
| Version B, but without FB... | 01/01/70 00:00 | |
| so... | 01/01/70 00:00 | |
| PCB layout... | 01/01/70 00:00 | |
| Answers... | 01/01/70 00:00 | |
| EMC | 01/01/70 00:00 | |
| Hhm, I wouldn't do that... | 01/01/70 00:00 | |
| AC power supply | 01/01/70 00:00 | |
| ground vias | 01/01/70 00:00 | |
| Locating of vias... | 01/01/70 00:00 | |
| Thank you very much... | 01/01/70 00:00 | |
| Sideplating? Thermal vias? | 01/01/70 00:00 | |
| Stackup | 01/01/70 00:00 | |
| Not such a good idea | 01/01/70 00:00 | |
| interrupted/split planes | 01/01/70 00:00 | |
| Elaboration | 01/01/70 00:00 | |
| Thank you... | 01/01/70 00:00 | |
| Nice link, Rob! | 01/01/70 00:00 | |
| Elaboration | 01/01/70 00:00 | |
| Explanation | 01/01/70 00:00 | |
| Elaboration | 01/01/70 00:00 | |
| What you propose isn't well suited for 4 layer boards | 01/01/70 00:00 | |
Hi Kai | 01/01/70 00:00 |