| ??? 12/08/05 15:36 Read: times |
#104890 - Murata better than others? No... Responding to: ???'s previous message |
Farshid said:
You are right,I rememeber that It has been told that if i could use those SMD Murata filters i could completely forget about the resistor. This isn't true! It depends on what series resistance the choke posseses. A 6-hole-choke consists of a simple piece of thick wire, which doesn't show any relevant series resistance. Combined with a capacitor not showing enough equivalent series resistance, this LC-filter will show hugh ringing, equally from which manufaturer the 6-hole-choke was made! So it highly depends on "built-in" series resistance of choke, whether an additional series resistance might be needed or not. For instance, there are standard ferrite beads and high current ferrite beads. The standard ones show series resistance of up to several Ohm. Such a choke would prevent ringing, but such a choke isn't suited to be used with higher currents! Only the high current ferrite beads do. But these show very low series resistance. This is a heat dissipation issue. And these can show hugh ringing again. Again this has nothing to do with manufacturer. It's a matter of construction. Kai |
| Topic | Author | Date |
| Vcc Line Filtering | 01/01/70 00:00 | |
| what are the resistors across the ferrit | 01/01/70 00:00 | |
| Some suggestions | 01/01/70 00:00 | |
| RE : Some suggestions | 01/01/70 00:00 | |
| I still would like to know | 01/01/70 00:00 | |
| LC-filter versus regulator | 01/01/70 00:00 | |
| Excellent | 01/01/70 00:00 | |
| That's really good, i was thinking that | 01/01/70 00:00 | |
| I have never used any such amd never had | 01/01/70 00:00 | |
| Filter position | 01/01/70 00:00 | |
| voltage drop for a ferrite at milliamps | 01/01/70 00:00 | |
| Line regulation | 01/01/70 00:00 | |
| sorry, that was tongue in cheek, of cour | 01/01/70 00:00 | |
| my bad | 01/01/70 00:00 | |
| if anyone should be sorry, that would be | 01/01/70 00:00 | |
| SMD,RC | 01/01/70 00:00 | |
| do you remember the math in a previous p | 01/01/70 00:00 | |
| Voltage Drop | 01/01/70 00:00 | |
| Murata better than others? No... | 01/01/70 00:00 | |
| Paralleling is only a theoretical remedy | 01/01/70 00:00 | |
| my mistakes... | 01/01/70 00:00 | |
| How many filters... | 01/01/70 00:00 | |
Tada! | 01/01/70 00:00 | |
| Exactly | 01/01/70 00:00 | |
| Thanks Kai | 01/01/70 00:00 |