Design of an undersampled BP ΣΔ modulator using LC and time-interleaved resonators

In this paper, we present the architecture of a bandpass sigma-delta modulator combining LC and two-channel time-interleaved resonators. The impact of using a two-channel time-interleaved resonator is discussed first. Then, we propose a general method to design undersampled Sigma-Delta modulators using such an architecture with different feedback signals and loop delays. The architecture and the method are validated with the simulation of a sixth order bandpass Sigma-Delta modulator using two LC resonators and one time-interleaved resonator.