Hello, I am currently working with the FPGA Board ZYBO Z7020. Part of my current task is: Apply a voltage to the AD2, the FPGA contains some logic and has to output the same Voltage with a DA2. I configured a VHDL I2C Master for communication with the AD2. I also attached an image with how I added the pullup Resistor in the schematic. I am using the internal voltage reference, which equals VCC = 3,3V. I am also watching the SDA Line with an oscilloscope to have a look at the data the ADC sends to me. I can apply an input voltage (DC) to the AD2 with a Waveform Generator. The AD2 works in High Speed mode (1MHz Clock). The configuration I use is: "00010011". The big problem with the SDA Data from the AD2 is: It reaches its maximum at 1,65V Input Voltage, so at 1,65V input voltage, all bits of the 12 bit data are '1'. I just can't figure out, why that's the case. The jumper on the AD2 board is set to "REF", the configuration tells the AD to use this reference and not an external one and the VCC at the PMOD surely delivers 3,3V. Any idea about what I am doing wrong? EDIT: I am only using Channel 0 for conversion.