Double-sampling analog-look-ahead second order ΣΔ modulator with reduced dynamics

A double sampled second order ΣΔ modulator with an analog look ahead (ALA) approach is presented. The proposed architecture provides an extra clock period to be used for the quantization. The feedforward path in both integrators allows the further reduction of the output voltage swing, relaxing also the slew-rate requirements of the op-amps. Moreover, the modulator enables the reduction of the number of quantization levels in the quantizer, thus the overall power consumption of the modulator would be significantly reduced. The proposed solution has been simulated at behavioral level by considering an improved model which takes into account the slew-rate and bandwidth limits.