Other Parts Discussed in Thread: DP83825I
I am working on a PCB that will be using the DP83825I, connected to the MAC on a 6748 DSP, and connected to an Ethernet jack which has internal magnetics. Regarding the EVM board, it is very hard to follow signals on the schematic, and the PCB is missing many reference designators, making it very challenging to use as a reference. These are the documents I am looking at (please confirm they are correct):
I have a number of questions I'm hoping can be answered:
- Can you provide a MFG P/N or details on type / case size / etc. for the 4700pF cap (C28) and 1M resistor (R37) that go from earth ground to system ground? Where are they located on the board?
- Why are the series resistors going to J9 "DNP"? Don't they need to be populated for the RMII interface to work?
- Is C23 there for switch debounce, or would it be needed in a design where the RESET line is being controlled?
- Why are there 33 ohm resistors (R9, 10, 17) placed between various RMII signals?
- In my design, are series termination resistors needed on the RMII lines?
- Is an external pulldown resistor needed on CRS_DV?
Thanks in advance for you help with this.