Would you please tell me where should I soldering the external 3.3 V DC power supply to my AD5933 Evaluation Board? Please take a look at the attached picture, am I doing the right way? Thanks a lot.
The AD5933 is powered directly bu the USB.
If you want to power the board externally, use the J2 connector (placed on the corner of the board) and change LK6 connector to position B.
In the AD5933 evaluation board, I have a question related to RFB( feedback resistor). Do we have to place an external resistor (say RFB = 200 kΩ)on the board separately or it is a programable resistor from software? Please reply.
No it is not a programmable resistor, you need to place a physical resistor on the board between the two female sockets where it is marked "RFB."