CDCE62002: SERDES Jitter Clearner: How it works?

Hi Itoh,

The MUX for input selection is just a regular smart MUX that can automatically select inputs. The idea for "Serdes start-up and clock cleaner" is that both "REF_IN" pins and "AUX_IN" pin can be connected in the same time and input  source can be switched back and forth between the two using SPI. So when clocking is needed, switch to XTAL input; when jitter cleaning is needed, switch to REF_IN as the input source.

Although this device is not the best jitter cleaner that TI can offer, the PLL itself provides jitter cleaning to the recovered clock, as recovered clock is very noisy. By replacing the recovered clock phase noise profile with internal VCO phase noise with narrow loop bandwidth, jitter cleaning can be realized.

Regards,
Hao

Hi Hao-san,

Thank you for your reply. Do you mean the replacing recovered phase clock phase noise by VCO phase noise is sufficient for the most of applications? Otherwise, can you please suggest better jitter cleaner device TI can offer?

Regards,

Itoh

Hi Itoh-san,

It depends on customer's requirements for jitter performance. If better jitter cleaning is needed, please refer to TI jitter cleaner selection guide: http://www.ti.com/clock-and-timing/jitter-cleaners/products.html

Popular parts include LMK04828, LMK04832, LMK05318

Regards,
Hao

Hello Itoh-san,

You are correct, XTAL is not needed (optional) if CDCE62002 is only used for jitter cleaner.

Regards,