AR# 1297: 5.x Xchecker - How can I use it on low-power "L" 3.3V parts?
5.x Xchecker - How can I use it on low-power "L" 3.3V parts?
Several Xilinx families now have members that are low-power 3.3V parts, such as the 3000L and the 4000L. The Xchecker cable itself is designed for use with 5V parts, but there is a special adapter that will allow operation with 3.3V parts.
As detailed in the "HardWare & Peripherals User Guide", pg.3-3, an optional 3.3V adapter to the Xchecker accepts Vcc supplies from 2.9V to 5.25V. This adapter contains a voltage step-up circuit that generates the 5V needed by Xchecker.
Since it can accept voltages up to 5.25V, there is no need to remove the adapter when using 5V parts.