Forum Post: How to adjust the output voltage of TPS63700 by DAC?

Hi,

    I want to design a -2 —— -10V adjustable power supply. In my former design of positive output (buck), it is easy to adjust the output voltage. I use a DAC to sink and source current at FB pin which changes the output voltage. The DAC and the buck converter are both GND as reference. In DC-DC inverter, how to do with TPS63700? If I use the negative output rail as the reference GND of DAC, it is hard to power the DAC and the I2C communicaiton must be isolated. If I use the GND of TPS63700 as the reference of DAC, where can I sink and source current to adjust the output voltage? The FB pin or other nodes?

   Thanks.