| ??? 04/09/08 13:52 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#153055 - Extend over a distance... Responding to: ???'s previous message |
Kai:
On the products I work on these days (high performance enterprise server systems) it is very common to have "long" I2C and SMBus traces. And the fact that the bus drivers are very often built in to silicon that has blazingly fast fall times causes problems of just the sort you describe. It is not uncommon to have series resistor terminations at the drivers to prevent these problems. Sometimes these need to be 50 ohms of even higher and create a definite trade off with the size of the pullup resistor elsewhere on the bus (the series matching resistor acts a voltage divider with the pullup when creating the Vol for devices receiving the signal from a driver behind the series resistor). Michael Karas |
| Topic | Author | Date |
| I2C pullup requirements | 01/01/70 00:00 | |
| Multi master | 01/01/70 00:00 | |
| Pull-up is needed | 01/01/70 00:00 | |
| Thanks | 01/01/70 00:00 | |
| Confirm pullup needed | 01/01/70 00:00 | |
| correct all | 01/01/70 00:00 | |
| It depends | 01/01/70 00:00 | |
| not just that | 01/01/70 00:00 | |
| I2C R pull ups Requements | 01/01/70 00:00 | |
| Or use a constant Current Source | 01/01/70 00:00 | |
| and a good one if it is .. | 01/01/70 00:00 | |
| Hhm... | 01/01/70 00:00 | |
| Extend over a distance... | 01/01/70 00:00 | |
Thanks for this informative reply! | 01/01/70 00:00 | |
| OK | 01/01/70 00:00 |