High Speed Continuous-Time Bandpass Σ ADC for Mixed Signal VLSI Chips

With the unremitting progress in VLSI technology, there is a commensurate increase in performance demand on analog to digital converter and are now being applied to wideband communication systems. sigma Delta (Σ ) converter is a popular technique for obtaining high resolution with relatively small bandwidth. Σ ADCs which trade sampling speed for resolution can benefit from the speed advantages of nm-CMOS technologies. This paper compares various Band pass sigma Delta ADC architectures, both continuous-time and discrete-time, in respect of power consumption and SNDR. Design of 2nd order multibit continuous time band pass Σ modulator is discussed with the methods to resolve DAC non-idealities.