具雙量化法之多階多位元三角積分調變器設計與實作

Design and Implementation of High-Order Multi-Bit Delta-Sigma Modulator using Dual-Quantization Technique

呂建林(Chien-Lin Lu)

指導教授 ： 宋國明

國立臺北科技大學/電資學院/電機工程系所/碩士(2010年)

摘要

本論文主要探討有兩個部分，第一部分探討的內容包含切換電容式與切換電流式之非理想效應的成因與補償；兩種切換技術並在相同條件下，進行最大訊號雜訊與失真比、晶片面積等比較。至於實際的硬體電路，在切換電容式方面，利用不受寄生電容(parasitic-insensitive)影響之切換電容式積分器來改善寄生電容所產生的非線性問題；在切換電流式方面，提出一個利用回授電路降低輸入阻抗以及共模前饋電路改善輸出共模位準的電流取樣電路。第二部分係針對切換電容式三角積分調變器，做更深入的探討，並設計一個使用雙量化法之多階多位元切換電容式三角積分調變器，雙量化法旨在取得多位元的較小量化誤差與單一位元的絕對線性回授優點，其中次類比數位轉換器(sub-ADC)則以快閃式類比數位轉換器架構來實現多位元量化作用。
本論文共設計出三個系統電路，均採用TSMC 0.18μm 1P6M互補式金氧半導體製程完成，分別為二加一階一位元切換電容式與二加一階一位元切換電流式與二加二階三位元切換電容式三角積分調變器；模擬結果顯示，在取樣頻率為5.12 MHz、超取樣率為128與頻寬為20 kHz的條件下，三個電路可得到最大訊號雜訊與失真比分別為87.3 dB、84.8 dB與96.5 dB。

關鍵字

三角積分調變器 ； 切換電流式 ； 切換電容式 ； 雙量化法 ； 多位元量化器

並列摘要

This thesis focus on two topics, one is to study the cause of non-ideal effect and the compensations of switched-capacitor (SC) and switched-current (SI) technique.；In this topic, the comparison between the maximum SNDR and chip area is made under the same conditions. Moreover, a switched-capacitor parasitic-insensitive integrator is used to improve the non-idealitie which produced by parasitic capacitor in voltage mode. Conversely, we use sample-and-hold circuit which consists of both a feedback circuit is used to reduce the impedance at the input and a common-mode feedforward (CMFF) circuit to improve the common-mode offset at the output in the current mode. The other one is focused on the design of SC delta-sigma (Δ-Σ) modulator. That is, a high-order multi-bit delta-sigma modulator with dual-quantization technique is proposed in this topic. The dual-quantization technique is not only to reduce the quantization noise of multi-bit quantizer, but also to have intrinsically linear feedback of a single-bit DAC. Notify that the sub-ADC is made of a flash ADC.
In this thesis, three systems are proposed and fabricated with TSMC 0.18

並列關鍵字

delta-sigma modulator ； switched-current technique ； switched-capacitor technique ； dual-quantization technique ； multi-bit quantizer

參考文獻

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