| ??? 12/01/08 22:34 Modified: 12/01/08 22:41 Read: times Msg Score: +1 +1 Informative |
#160471 - Instable, very very probably! Responding to: ???'s previous message |
Composite amplifiers shouldn't be used, unless you know very very well what you do.
Unity gain composite amplifiers are not stable usually, because the phase lag in the feedback loop of two Opamps in series will exceed 180° at frequencies below unity gain bandwidth very very probably, even without any capacitive load, resulting in wild oscillations! That's why in the link from Michael the composite amplifiers are all set to provide some gain. Additonal capacitive loads at output of composite amplifiers should be avoided at all and kept at absolute minimum. Because of the mentioned risks, I never used any composite amplifier in my job so far. Kai |
| Topic | Author | Date |
| Composite OpAmp | 01/01/70 00:00 | |
| Possible | 01/01/70 00:00 | |
| Maybe Helpful Info | 01/01/70 00:00 | |
Instable, very very probably! | 01/01/70 00:00 |