What is the proper termination scheme for Virtex-II and Virtex-II Pro LVPECL drivers?
The termination scheme for either Virtex-II or Virtex-II Pro LVPECL should consist of a 100 / 187 / 100 ohm resistor network at the driver, and a 100 ohm differential termination resistor at the receiver. This scheme is outlined in both the Virtex-II and Virtex-II Pro User Guides:
Supported LVPECL standards are as follows:
- Only LVPECL_33 is available and supported in Virtex-II devices.
- Only LVPECL_25 is available and supported in Virtex-II Pro devices.