PCK2023 datasheet(21/30 Pages) PHILIPS

21 / 30 page

Philips Semiconductors

Product data

PCK2023

CK408 (66/100/133/200 MHz) spread

spectrum differential system clock generator

2001 Sep 07

APPLICATION NOTES

Optimum performance of the PCK2023 can only be achieved

through correct implementation in the system board. This application

note addresses many of the issues associated with integrating the

PCK2023 on a system board. Descriptions for circuit board layout

and decoupling are provided in this application note.

Circuit board layout

It is possible to generate a circuit board with the proper

characteristics using four-layer configuration. Figure 11 shows the

layer stack-up. It is critical to keep the clock signals on a plane next

to a ground plane to ensure they are ground referenced otherwise

the clock signals may experience significant distortion and added

jitter. Static signals (such as SPREAD, PWRDWN, etc.) can be

placed on a layer next to the power plane.

The components associated with the clocks should be placed on the

same layer as the PCK2023 IC. This will allow the layout to avoid

the use of vias for interconnect, thereby reducing node capacitance

and trace inductance. All components should be placed as close to

the IC as possible.

CLOCK SIGNALS

GROUND

POWER

STATIC SIGNALS

SW00857

Figure 11. Optimum board layout

PCK2023 데이터시트(PDF) 21 Page - NXP Semiconductors