ADC input driver

What is the frequency range of interest?  Do you want to be AC or DC coupled?  Do you need gain?  50ohms?

Task is to measure a (appr. 30V) DC current, which is generated by a generator, as detailed as possible,  directly at the coils (only with a short-circuit load, to measure delivered maximum power), for a time interval of  approximately 1 seconds.

Why do you need such a high performance ADC to do a DC measurement?  It seems like you want a sigma delta or or SAR.  Why do you need such a high sample rate? 

I have to track accurate time signal changes. I need accurate detailed signal transformations within a appr. 20 millisecond time span

You need to take a sample every 20ms or you need as many samples as possible in 20ms?  20ms is 50Hz.  I still don't know why you need the LTC2123.

I need as many samples as possible in 20ms.

Ok, the LTC2123 also has a JESD204B interface, so you will need more complexity in the FPGA, is this something you can work with?

Ok, the LTC2123 also has a JESD204B interface, so you will need more complexity in the FPGA, is this something you can work with?

o yes, with a Xilinx KC705 work fine. I need only a frontend for a DC monitoring.

Ok, then you are going to need to attenuate the 30V rail into the 2Vpp input range, probably a resistor divider can do that.  Then you will need to use an amplifier like the LTC6409 to do the single ended to differential translation into the LTC2123.  This signal chain can be DC coupled and drive the ADC DC coupled. 

You are the best.

Thank you very much and wisch you all the best.

best regards

Tell that to my boss.  Let me know if you have any other questions. Good luck.