DP83848K: DP83848K Clock synchronous change from SPXO to Crystal

user5158211

Part Number: DP83848K
Other Parts Discussed in Thread: DP83822I

Hello ,The DP83848K can clock synchronous when used SPXO, In order to cost down , Plan to use Crystal replace the SPXO ,such as the SMSC LAN8720A application , Please help offer solution for DP83848K , Thank you!

over 7 years ago

0 Ross Pimentel over 7 years ago

TI__Mastermind 23675 points

You can use any crystal with the DP83848K that meets its crystal specification (found on page #66 in the datasheet).
The LAN8720A is an RMII PHY, which the DP83848K supports as well.
When operating the DP83848K in RMII operation, it must be supplied a 50MHz clock to XI pin and there is no support for crystal.
If you want a solution for RMII with a 25MHz crystal, you can use the DP83822I.

0 user5158211 over 7 years ago in reply to Ross Pimentel

Prodigy 130 points

Hello, The RMII function is difference, LM8702A support the Crystal in REF_CLK Out Mode page 34, But DP83848K only support oscillator in Page33. Any solution as the only a crystal used to meet costdown?

0 Ross Pimentel over 7 years ago in reply to user5158211

TI__Mastermind 23675 points

Only the DP83822I supports RMII with external crystal and not oscillator.
The DP83848K does not support the operation you are looking for.

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DP83848K: DP83848K Clock synchronous change from SPXO to Crystal