A new 60.2 dB 2nd order delta sigma modulator using open loop buffers based on current conveyors

This paper presents a new delta sigma modulator concept based on fully differential current conveyors (CCII). CCIIs with their inherent high speed and linearity are capable of replacing the opamps function in many of the analog circuits. The proposed modulator in this paper utilizes three CCIIs to implement a 2^nd order delta sigma ADC. Simulation results show that the modulator has 60.2 dB of noise rejection capability for an input of -6dBFS / 62.5kHz and dynamic range of more than 60dB. The total power consumption is found to be 0.61mW for a sampling frequency of 10MHz in a 1V/90nm TSMC process.