Other Parts Discussed in Thread: AM67A
Tool/software:
Hi,
Customer will try to use external reference clock source ("SERDESx_REFCLKx_P/N" pin of AM67A) for PCIe.
They are going to refer EVM schematic to understand recommended circuit. You do not implement external clock (LMK3H102) on lastest EVM(PROC170E3B), but we know you have implemented this clock device on previous EVM (now we refer "PROC170E1".)
When I checked this previous EVM schematic, you have implemented 33 ohm series resistor(R40, R39) on clock line.
They will plan to use same device(LMK3H102) as EVM to their custom board.
(Output setting of clock soruce will be "LP-HCSL". Maybe same as EVM.)
Then I have following question.
* Should we need to implement "33ohm" series resistor on reference clock line ?
(I think these resistors are for damping resistor, but, if possible, please tell what purpose these are implmented and how you decide value.)
Best Regards,