電流操縱數位類比轉換器設計於雙模陣列式感測器讀取電路

The Design of Current-Steering DAC for Dual Mode Array Sensor Readout Circuit

溫于德(Yu-De Wen)

指導教授 ： 孫台平

國立暨南國際大學/科技學院/電機工程學系/碩士(2014年)

摘要

本論文完成雙模切換式緩衝放大器注入型(Buffer direct injection, BDI)與直接注入型(direct injection, DI)並結合Current Steering DAC之讀取電路設計與實現，為了能更廣泛使用於多種類型感測器，結合DI 與BDI 各優點並於感測器種類上選擇不同對應電路架構，加入開關控制來進行讀出電路架構的切換動作，達到電路內可同時具有BDI & DI 兩種讀出電路模式。完成可切換模式陣列型讀出電路，利用兩種不同讀取電路相對應感測器達到最佳訊號擷取。並對於電路之功率、效率值、佈局面積、電路雜訊等方面做探討與分析。Current steering DAC可用來控制感測器偏壓，以及控制Gain stage偏移大小。
讀出電路主要設計考量於緩衝放大器的增益、頻寬與雜訊，電路模擬結果增益(gain)達到40dB。此電路採用TSMC 0.35um 2P4MCMOS 5V 製程技術，設計了10x8 陣列大小的讀出電路，設定電流輸入範圍為10p~10 nA，電路輸出擺幅為2 V，模擬訊號雜訊比為65dB，模擬電路功率消耗為9.705mW。Current Steering DAC結果為7bit，INL≦ ± 0.9 LSB、DNL≦ ±0.4LSB功率消耗0.299mW SNR為40dB。量測結果電流輸入範圍為10p~10 nA，積分時間可調，電路輸出擺幅為2V，訊號雜訊比為52dB，整體晶片電路功率消耗為10.31mW。

關鍵字

雙模切換式讀取電路 ； 生物感測器讀取電路 ； 電流操縱數位類比轉換器

並列摘要

This paper proposes dual-mode buffer direct injection (BDI) and direct injection (DI) with current steering DAC readout circuit design. Combining advantages of DI with BDI is used many types of sensors applications. According to the sensor types, added switch to control readout circuit structure become BDI & DI. It has completed dual switch mode which has detected different sensor at array integrated readout circuit. We debated from the power, efficiency, injection efficiency, layout area and circuit noise. Current steering DAC is used to control the biosensor bias voltage and control Gain stage offset voltage.
Gain, bandwidth and noise are the readout circuit design of chief considerations.
Simulation result of amplifier gain is 40dB. The Circuit is simulated by using TSMC 0.35um Mixed Signal 2P4M CMOS 5V process. The input current setting 1nA to 10nA, the simulation output voltage swing is 2V and the total power consumption is less than 9.76mW. The DAC has the following characteristics: 7bit, INL≦ ± 0.9 LSB,DNL≦ ±0.4LSB and cosumes power 0.299mW. The measurement current setting 10p to 10 nA. The integration time would adjust. The circuit output swing is 2V, signal to noise ratio is 52dB, and the full chip circuit power consumption is 10.31mW.

並列關鍵字

Dual switch mode readout circuit ； Biosensor ROIC ； Current steering DAC

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