DP83848C: The problem about clock signal

Kanichiro Nozaki

Part Number: DP83848C

Hi,

I am facing the following issue in using dp83865C.

In my design, 25MHz clock is provided from the oscillator to X1 pin 34.
However, the clock signal cannot be confirmed in any of CLK_OUT, RX_CLK, and TX_CLK after power up.
Therefore, I am currently facing the problem of not being able to communicate.
Is there any initial processing required?
as a side note, RESET_N and PWR_DOWN have been pulled up.

Thanks,
Kanichiro

over 4 years ago

0 Kallikuppa Sreenivasa over 4 years ago

TI__Guru**** 207800 points

reviewHello kanichiro Nozaki

Thank you for the query.

Can you please confirm the part number.

Also, please share the PDF schematics for a quick review.

Regards,

Sreenivasa

0 Kanichiro Nozaki over 4 years ago in reply to Kallikuppa Sreenivasa

Prodigy 10 points

Hi Sreenivasa ,

Thanks for the reply.

sorry. I made a typo. I am using dp83848C correctly.
I attached my schematic.
Please note that since it is used for work, there are some secret parts and only a part of the schematic can be attached.

8484.schematic.pdf

Kanichiro

0 Kallikuppa Sreenivasa over 4 years ago in reply to Kanichiro Nozaki

TI__Guru**** 207800 points

Hello kanichiro Nozaki

Thank you for the inputs and this is fine.

Oscillator : Please remove R411 and check the clock output. Also please check the clock output at X2- pin 33.

If this is fine, please provide an RC across the reset pin to hold the rest as shown in POWER-UP TIMING to ensue proper or reset the device externally after the supply is stabilized.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa over 4 years ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 207800 points

Hello kanichiro Nozaki

Did you hae a chance to do some tests and is the issue resolved?

Regards,

Sreenivasa

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DP83848C: The problem about clock signal