| ??? 11/11/07 18:27 Modified: 11/11/07 18:30 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#146869 - Four decoupling caps are needed! Responding to: ???'s previous message |
Reza said:
My question is if a signal dose not return via ground then how should I route it to minimize current loop and reduce EMI. For example consider a very fast Opamp that is connected to another fast inverting Opamp. Then current from output of second OpAmp U2 will not return from ground it will return from either VCC or VEE to supply I usually use two decouple 100nF cap from VCC of U1 to VEE of U2 and from VEE of U1 to VCC of U2(not shown) but how should I route to minimize current loop. You must use four decoupling caps: From Vcc (U1) to GND, from Vee (U1) to GND, from Vcc(U2) to Gnd and from Vee(U2) to GND! All your signal currents are then flowing through these decoupling caps and via the ground plane. Kai |
| Topic | Author | Date |
| Signal return path via supply line, how to route? | 01/01/70 00:00 | |
| Four decoupling caps are needed! | 01/01/70 00:00 | |
Thank you very much indeed! | 01/01/70 00:00 |