CYUSB3065 REFCLK and CLKIN inputs

[abushuev_490810]

The datasheet for the CYUSB3065 IC has a note as follows:

Note: REFCLK and CLKIN must have either separate clock
inputs or if the same source is used, the clock must be passed
through a buffer with two outputs and then connected to the clock
pins.

Is there any way to decrease the cost and the footprint of the solution?

Is it acceptable to connect the REFCLK and CLKIN inputs via 33 Ohm resistors to one clock source?

Thank you in advance!

[JayakrishnaT_76 · Accepted solution]

Hello,

We recommend to follow the Note given in the CX3 datasheet. The same is mentioned in the thread below:

https://community.cypress.com/t5/USB-Superspeed-Peripherals/CYUSB306X-REFCLK-and-CLKIN-inputs/m-p/16...

However, we have also seen many customers driving CLKIN and REFCLK using the same clock source (without using a buffer) without facing any issues. When this approach is followed, the clock source should have sufficient strength for driving both CLKIN and REFCLK pins.