We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 8654

Virtex/-E/-II - Are input and output I/Os 5V tolerant?


Keywords: 1.8V, bi-directional, tolerance, compatible

Are Virtex/-E I/Os 5V-tolerant? If I use a 100-ohm resistor, can a bidirectional bus interface to 5V?


When you place a 100-ohm resistor in a series with a Virtex-E pin, only the "input configured only" pin is 5V tolerant. You cannot configure the pin as an INOUT or as an OUTPUT with 5V driving that trace line. The resistor in series drops the Voh output voltage. As a result, it might not meet the input specifications of the interfacing device.

1. For PCI 5.0V systems, use Virtex devices or reference (Xilinx Answer 11904).
2. Never directly apply 5V to a Virtex-E pin.
AR# 8654
Date Created 08/21/2007
Last Updated 04/07/2009
Status Active
Type General Article