A 8-bit SAR ADC using current mode approach for bio-medical applications

This paper deals with the design of a SAR-ADC with 8-bit resolution suited for bio-medical application. The design of the key components of the SAR ADC namely, DAC, Comparator and Sample and Hold circuit (S/H) has been carried out using current mode approach with the DAC operating at sub-threshold regime. The input current range is 10nA to 2.57μA with 10nA as the LSB. The circuit has been designed in UMC 180nm technology Twin-Well Process.