Hello WE Team,
In Application note ANP085, For 10BASE-T1 transformer design, you have mentioned a minimum value of 100 nF capacitor is required to meet the limits of IEEE802.3cg (Capacitor C3 in figure 16).
What is the maximum capacitor value limit for the same design (with the same transformer)?
Regards
Suresh
Hi suresh11
Here we have run the simulations for the return loss for different caps:
You can see differences up to 470 nF. The 100 nF are also not bad for the RL, but then have problems with the voltage drop (droop).
With values above 400 nF, the difference is hardly noticeable, so it makes no sense to use even larger values.
The droop results in the following:
And as a comparison chart droop and capacity:
So from 300nF or 400 nF, you hardly gain anything by increasing the capacitance.
But since there are differences between the simulation and the real components due to manufacturing tolerances, we got the best values with the 470 nF capacitor.
I hope this helps you.
