Installation Guide

C5621 and C33 User Guide
1/1553-KRD 131 24 Uen Rev D 2011-11-22

Ericsson AB 2011
14 (37)
Ericsson Confidential
4.2.1 Clock Routing
 Must be routed with a controlled impedance (50-60 Ohm)
 Should not be routed over a discontinuous GND plane
 Keep clock traces as short as possible
 Place serial termination close to transmitter output
 Crosstalk:
o Crosstalk falls off with the square of the distance, therefore
adequate spacing is a good method in reducing crosstalk
o As a rule of thumb, 3xH can be used for all clock signals:
Figure 3, Spacing rule
 Involved signals:
o SYSCLK
o RTC_CLK
o UIM_CLK
4.2.2 USB Routing
 Traces should be routed as a differential pair, matched in length.
 Differential Impedance between the traces shall be 90 Ohm
 Involved signals:
o USB_DP
o USB_DM
H
3xH
Reference plane
Aggressor Victim