Design of Σ-Δ Modulator Using Switched-Capacitor Technique

2011; Elsevier BV; Linguagem: Inglês

ISSN

1879-2391

Autores

Weidong Wang,

Tópico(s)

Analytical Chemistry and Sensors

Resumo

A single-loop 3rd-order switched-capacitor Σ-Δ modulator was designed and implemented based on standard 0.18 μm CMOS technology.In this circuit,a chain of integrators with weighted feed-forward(CIFF) summation structure and optimized single-stage Class-A OTA with positive feed-back were proposed to minimize power consumption.And a current optimization technique was utilized to reduce power consumption of the OTA.The Σ-Δ modulator achieved an over-sampling ratio of 128,a clock frequency of 6.144 MHz,a bandwidth of 24 kHz,a peak SNR of 100 dB,and a dynamic range of 103 dB.The whole circuit consumed 2.87 mW of power from a single 1.8 V supply voltage.

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