A multi-bit sigma-delta modulator for wideband applications

A multi-bit sigma-delta pipelined modulator is proposed. The new topology utilizes noise shaping in conjunction with pipelined concept. The converter consists of pipelined stages each stage consisting of a sigma-delta modulator with feedforward path. This ADC can achieve very good performance even when it is use with a low oversampling ratio, which reduces the demands on the circuit speed. Therefore, a multi-bit sigma-delta pipelined topology is suitable for wideband ADC implementation. The performances of this topology are analyzed and compared with other topologies. Simulation results are included to verify the theoretical considerations.