A Study To Realize A 1-v Operational Passive Σ-Δ Modulator By Using A 90 Nm Cmos Process

摘要

A 1-V operational sigma-delta modulator with a second-order passive switched capacitor filter is designed and fabricated by using a 90 nm CMOS process. No gate-voltage bootstrapped scheme is adopted to drive analog switches, and the voltage gain of a comparator is chosen to be 94 dB. The experimental results show that the peak SNR reached 68.9dB with a frequency bandwidth of 40 kHz when the clock was 40 MHz.