Post History
are there more elements contributing to this effect that I have not placed in the circuit? Well, you have a simulator and it should be really easy to remove C_windings and observe if the ringi...
Answer
#2: Post edited
by
Andy aka
·
2024-05-08T08:52:32Z (7 months ago)
- > _are there more elements contributing to this effect that I have not placed in the circuit?_
- Well, you have a simulator and it should be really easy to remove C_windings and observe if the ringing frequency alters. If it does then there is another capacitor hidden away in your circuit (aka drain-source capacitance) that sets the new ringing frequency.
- > _Can ringing on digital signal lines also be represented in the same way, where L1 is the total inductance of the signal line and C_windings is the capacitance between the two ends of this signal line?_
- No, because usually on digital signal lines the problem is one of reflections rather than resonance. It may look like resonance but, it's something else tied up in transmission-line theory.
- > _Is adding a termination resistor on data lines essentially providing a path for the collapsing magnetic field of the line inductance that dampens the LC oscillation? (Path in red)_
No, the resistor is there to prevent reflections returning back down the line. It's a transmission-line effect that we are normally dealing with here on digital signal lines.
- > _are there more elements contributing to this effect that I have not placed in the circuit?_
- Well, you have a simulator and it should be really easy to remove C_windings and observe if the ringing frequency alters. If it does then there is another capacitor hidden away in your circuit (aka drain-source capacitance) that sets the new ringing frequency.
- > _Can ringing on digital signal lines also be represented in the same way, where L1 is the total inductance of the signal line and C_windings is the capacitance between the two ends of this signal line?_
- No, because usually on digital signal lines the problem is one of reflections rather than resonance. It may look like resonance but, it's something else tied up in transmission-line theory.
- > _Is adding a termination resistor on data lines essentially providing a path for the collapsing magnetic field of the line inductance that dampens the LC oscillation? (Path in red)_
- No, the resistor is there to prevent reflections returning back down the line. It's a transmission-line effect that we are normally dealing with here on digital signal lines.
- Unfortunately if you haven't studied transmission lines (a big and difficult subject) you can easily mistake t-line effects for LC oscillations.
#1: Initial revision
by
Andy aka
·
2024-05-08T08:49:27Z (7 months ago)
> _are there more elements contributing to this effect that I have not placed in the circuit?_ Well, you have a simulator and it should be really easy to remove C_windings and observe if the ringing frequency alters. If it does then there is another capacitor hidden away in your circuit (aka drain-source capacitance) that sets the new ringing frequency. > _Can ringing on digital signal lines also be represented in the same way, where L1 is the total inductance of the signal line and C_windings is the capacitance between the two ends of this signal line?_ No, because usually on digital signal lines the problem is one of reflections rather than resonance. It may look like resonance but, it's something else tied up in transmission-line theory. > _Is adding a termination resistor on data lines essentially providing a path for the collapsing magnetic field of the line inductance that dampens the LC oscillation? (Path in red)_ No, the resistor is there to prevent reflections returning back down the line. It's a transmission-line effect that we are normally dealing with here on digital signal lines.