The VADJ power rail requires special attention. It is an adjustable rail that powers the FMC mezzanine connector, user push-buttons, switches, XADC Pmod connector and the FPGA banks connected to these peripherals (banks 15, 16, 17). The feedback pin of the VADJ regulator is connected to a resistor network modifiable by jumper JP6. Changing its position changes the resistor divider in the feedback loop, thereby changing the voltage on the regulator’s output. The possible voltages are listed in Figure 2. If JP6 is not set, the VADJ voltage defaults to 1.2 V. This feature enables setting the VADJ voltage to suit a certain FMC mezzanine card or application.
