I have interface AD7986 with FPGA. With Internal reference and Turbo mode, I am reading data in CS MODE, 4-WIRE WITHOUT BUSY INDICATOR.
Clock – 25MHz
Conversion time used is 600ns
Data reading during acquisition.
Below are digital output code got for respective voltage
4 volt - 0x1F90E
3 volt - 0x178A9
2 volt - 0xE94A
1.5 volt - 0x7145
1 volt - 0x0148
0.5 volt - 0x3EF15
What may be the reason for this observed voltage drop.
Please find attached schematics.
Thanks and Regards,
Isn't clear in the schematic where the source or what's your common mode input voltage? Keep the common mode within specified in the datasheet.