22©2018 Integrated Device Technology, Inc. March 15, 2018
5P49V6965 Datasheet
Output – Single-ended or Differential Clock Terminations
LVDS Termination
For a general LVDS interface, the recommended value for the termination impedance (ZT) is between 90Ω and 132Ω. The actual value
should be selected to match the differential impedance (Zo) of your transmission line. A typical point-to-point LVDS design uses a 100Ω
parallel resistor at the receiver and a 100Ω. differential transmission-line environment. In order to avoid any transmission-line reflection
issues, the components should be surface mounted and must be placed as close to the receiver as possible. The standard termination
schematic as shown in figure Standard Termination or the termination of figure Optional Termination can be used, which uses a center tap
capacitance to help filter common mode noise. The capacitor value should be approximately 50pF. In addition, since these outputs are
LVDS compatible, the input receiver's amplitude and common-mode input range should be verified for compatibility with the IDT LVDS
output. If using a non-standard termination, it is recommended to contact IDT and confirm that the termination will function as intended.
For example, the LVDS outputs cannot be AC coupled by placing capacitors between the LVDS outputs and the 100Ω shunt load. If AC
coupling is required, the coupling caps must be placed between the 100Ω shunt termination and the receiver. In this manner the
termination of the LVDS output remains DC coupled.
Figure 14. Standard and Optional Terminations
LVDS
Driver
LVDS
Driver
LVDS
Receiver
LVDS
Receiver
Z
T
C
Z
O
Z
T
Z
O
Z
T
Z
T
2
Z
T
2
Standard Termination
Optional Termination
