A double-sampling SC-resonator for low voltage bandpass ΔΣ-modulators

In this paper, a novel double-sampling switched-capacitor (SC)-resonator with high performance is proposed. The quality factors of the resonators, high notch Q-value and the accurate notch frequency, are analyzed at the transfer function level. Furthermore, their effect on the quantization noise shaping in the implementation of the BP ΔΣ-modulator is explained. Discrete-time resonator topologies are discussed and the double delay resonator structure is shown to have potential to implement high performance resonators. A double-sampling switched-capacitor resonator is presented with comparisons to reported structures. The nonidealities are analyzed in the light of the preceding theoretical scrutiny. The structure is found to be very insensitive to imperfections of the analog circuits and it has a low capacitive load leading to a low power consumption. Finally, a BP ΔΣ-modulator using the proposed resonator is presented along with behavioral level simulation results.