互補式金氧半導體影像感測器技術(II)-一個10位元連續逼近類比數位轉換器及系統偏壓電路

Abstract

近來，互補式金氧半導體影像感測器已經受到廣泛的注意，顧客對於微型化、低功率、低成本的需求成為其受到持續關注的主要原因。互補式金氧半導體影像感測器提供了整合超大型積體電路中各個系統在同一個晶片上的機會，並且減少了電路版上離散的電路元件數量，降低包裝成本。一個包含時序控制器，感測器陣列，訊號處理器，類比到數位轉換器，數位介面的單晶片照相機是可預期的。類比到數位轉換器的解析度及轉換速率對圖像品質有很大的影響，尤其是在錄影的應用。感測器的類比部份需要和PVT效應無關的偏壓電路以獲得穩定性及雜訊的壓抑。 本論文中報告10位元連續逼近類比數位轉換器及系統偏壓電路。所設計的電路以SPICE及台積電1P/5M 0.25微米 3.3V 的spice 模型模擬。

Recently, there has been a growing interest in CMOS image sensors. The major reason for this interest is the customer demand for miniaturized, low-power, and low-coast digital cameras. CMOS image sensors offer a great potential to integrate a significant amount of VLSI electronics on a single chip and reduce discrete components and packaging costs. It is now straightforward to envision a single-chip camera that has integrated timing and control electronics, sensor array, signal processing electronics, analog-to-digital converter (ADC) and full digital interface. The resolution and conversion rate of the ADC has much influence on the image quality especially for video application. The analog portions in the sensors require a system biasing circuit that frees from PVT effect to obtain stability and noise suppression. A 10-bit successive approximation ADC and the system biasing circuit are presented in this thesis. The designed circuits are simulated in SPICE and TSMC 1P/5M 0.25um 3.3V spice model.