Hi,
We need a clarification about the SERDES_CLKx AC Coupling Capacitors.
As per the AM389x datasheet SERDES_CLKN/P capacitors are 270pF (the typical value).
But the evm816x_Schematics(below) uses 0.1uF. Could you please let us know which
value should be used?
Actually the datasheet also mentions that,
The value of this capacitor depends on several factors including differential input clock swing.
For a 100-MHz differential clock with an approximate 1-V voltage swing, the recommended typical value
for the SERDES clock AC coupling capacitors is 270 pF. Deviating from this recommendation can result in
the reduction of clock signal amplitude or lowering the noise rejection characteristics.
So we believe the datasheet value is correct.
The second question is about the SERDES_CLKN and SERDES_CLKP pair differential impedance,
the datasheet "Table 8-10." mentions differential impedance as 100-ohms.
Is it true that External 100-ohm termination is not required and it is handled internally?
Best Regards.
Kummi
