A noise-coupled time-interleaved delta-sigma modulator with shifted loop delays

Noise coupling and time interleaving are effective methods for expanding the bandwidth of the low-power wideband delta-sigma modulators. In this paper, a discrete-time ΔΣ modulator topology with these two technologies, combined with shifted loop delays, is proposed. Noise coupling and time interleaving between the two channels enhance the effective order of the noise shaping function. Shifting the loop delays relaxes the critical timing for the DEM. Also, the last integrator in the loop filter performs both integration and active summation. To verify the effectiveness of this topology, a third-order noise-coupled time-interleaved ΔΣ modulator with shifted loop delays is analyzed and simulated.