dear
thank you very much for your help
at this point i learned that there was some missing key point to use this ic and those was
1) after power up of ads1256 sdatac command must be issued so it will accept any further command
2) every command should be issued by syncing drdy signal to get proper response from ads1256 ic
3) t6 and t11 must be added with respect to what type of command is issued
4) cs is not necessary but beneficial for some point of operation to terminate unfinished command
5) provide individual voltage regulator for ads1256 dvdd power supply because it did not start properly many times and it is confirmed on other posts also that it is little more sensitive to emi /esd noise so provide maximum isolation from any kind noise to its dvdd pin line and tvs diode is must on its dvdd pin
finely we had managed to run this ic with your informative help and we are very thank full for your guidance
well at this point i have analysed that this adc is good candidate for precision measurements but its state machine is real problem and on the other hand this ic is sensitive to esd/emi noise
and if we go for 2.5 hz update rate then we can get 20bit resolution which is noise free but above then only on 10hz sample rate its noise free bits reduced to 17-bits
any how this our economy class product but for really high precision we are still looking for better replacement part which works more robust in esd/emi noise and provides 20-bit accuracy for all 8 channels and at-least 5 samples/Sec per channel so plz suggest a suitable product or solution for this requirement where we want to use 20-bit dac for analog control signal i am going to mark this post answered as now this project is again going to hand over to our application engineer for further development where it will be finalized on minimum of four layer PCB to gain maximum performance
now dear i have another adc in list for another project and that's part no is ads1252 here we have some confusion relating to its operation plz guide us for its interfacing my question is what is the reset state of drdy/dout pin function
just like
if i pulled high serial clock line for five drdy cycles and released serial clock line to low then what should i consider to that what is the current drdy/dout function status and how to calculate adc clocks for one drdy cycle basically i want to use timer counter to determine dout status for data reading and once it is synced with timer so i can easily read the data from it while adc clock is being supplied from micro-controller so clock syncing procedure will work with out any problem and free up the processor for other tasks
regards
Shams Iqbal