| ??? 07/04/05 13:20 Read: times |
#96508 - Then use internal shielding Responding to: ???'s previous message |
Kuldeep said:
one more thing my pcb is not masked it is bare copper will it add to coupling. Capacitive coupling (also called stray coupling) is something that takes place between two or more conductors via intrinsic stray capacitance. If you have a solder mask on your PCB, does it relevantly influence this stray capacitance? No, because the dielectric material which you put in between is very thin. The only way to prevent stray coupling is, to put a metallic shield between the conductors, which you connect to a suited potential, mostly signal ground. Then, electrical field lines no longer go from one conductor to an other, but end on the grounded shield. This gives a hint how to fix your problem, even if you do not want to replace your plastic enclosure: Surround critical parts of your circuit with a metallic shield, inside the plastic enclosure and connect it to signal ground. Especially in high gain applications, this is a good remedy against instability, where a global enclosure (everything sitting inside) wouldn't help much. Kai |
| Topic | Author | Date |
| is it ground bounce | 01/01/70 00:00 | |
| No, hum or high frequency instability | 01/01/70 00:00 | |
| high frequency | 01/01/70 00:00 | |
| plastic enclosure | 01/01/70 00:00 | |
| Spray nickel | 01/01/70 00:00 | |
| nice idea | 01/01/70 00:00 | |
| cost vs working | 01/01/70 00:00 | |
| Then use internal shielding | 01/01/70 00:00 | |
| internal shielding | 01/01/70 00:00 | |
| Schematic, plan of whole setup? | 01/01/70 00:00 | |
| hi kai | 01/01/70 00:00 | |
| So where is the problem? | 01/01/70 00:00 | |
Then, good luck... | 01/01/70 00:00 | |
| Nickel paint | 01/01/70 00:00 | |
| Ground bounce | 01/01/70 00:00 | |
| and next week | 01/01/70 00:00 |