Other Parts Discussed in Thread: REF6050, REF6030,
Thanks for your response. Found that the analog input pin was not properly connected to the source and therefore SPI communication was improper
Now I want to finalise the circuit
1) First when I had recieved the board ADS8860EVM I connected the board using PHY to my PC
and via software of TI found that there was a fluctuation of 150 counts which was reduced to 20 counts
after I changed the input capacitor C1 to 0.1UF
2) I wanted to then connect the board to my MCU board containing msp430
Therefore I have connected the SPI lines on the ADS8860EVM to my microcontroller msp430 and disconnected PHY.
Also bypassed REF6050 and gave 3.3V reference to the ADC.
Also the same 3.3V was also suppiled to AVDD and DVDD.
Now I have got ADC count with a fluctuation of upto 60 counts.
3) Now I believe that the fluctuation would reduce if I replace REF6050 with REF6030 instead of bypassing the reference.
I would like to know what more need to be done to improve the stability of the ADC output.
I have attached the schematic of ADS8860 where I have mentioned the changes in the schematic done on ADS8860EVM schematic
Please suggest whether the changes are sufficient to improve stability and get reduced fluctuations upto 20 counts
or whether any further changes are required. I am asking before hand so that I can incorporate any other changes
before I could finalise the circuit