AD670 status is not recommended for new design. Are there any recommendation products for replacement of AD670?
It depends on how you are using the ADC. The AD670 has a differential, Instrumentation Amp like input stage. I don't know of any other 8 bit parallel output single supply ADCs with that kind of input. If you just need an 8 bit parallel output ADC use the ADC product selection guide to view the various ADI catalog part options available. If you are using the In-Amp functionality of the AD670 front end you will need to add a stand alone In-Amp ahead of the ADC.
Doug (the AD670 designer and yes I'm still here)
If we are still talking about the AD670, then yes as it states in the datasheet there are on-chip 10:1 resistor voltage dividers. The internal full scale range of the ADC is 0-250mV or +/-128 mV ( or 1mV/LSB ) and this range will be increased by 10X when the dividers are used (10mV/LSB). figures 2 and 3. The output data format, either unipolar or bipolar is set by the pinstrap pins 11 and 12.