可調節工作週期輸出的溫度感測電路分析與實現

The Analysis and Realization of Temperature Sensor with Duty-Cycle-Modulated Output

張柏森(Bo-Sen Chang)

指導教授 ： 陳淳杰

中原大學/電機資訊學院/電子工程研究所/碩士(2021年)

https://doi.org/10.6840/cycu202100577

摘要

本論文結合電源管理晶片以及感測器系統的實作，透過不同的電路設計學習各種設計技巧以及量測方法，其中包括低於1伏特帶隙參考電壓電路、低壓差線性穩壓器、高增益放大器以及溫度感測電路，所有的實作設計皆是利用台灣半導體研究中心所提供的0.18um 1.8V 3.3V 1P6M CMOS 製程進行設計。
　　低於1伏特帶隙參考電壓電路的電源電壓為1Ｖ，利用雙載子電晶體(BJT)本身的溫度特性產生正負溫度係數，經過線性組合後互相抵銷溫度參數，產生與溫度無關的輸出電壓。攝氏溫度-40℃~125℃產生的輸出電壓為597~601mV，功耗為44.34uW。
　　低壓差線性穩壓器電源電壓即為輸入電壓，從1.2V~3.3V皆為可輸入範圍，由回授電阻取得回授電壓，經誤差放大器與參考電壓比較，並輸出訊號給傳輸電晶體調整工作狀態，達到輸出電壓穩定於1V，線性調節度為0.01%，負載調節度為0.62%，輕重載切換時無震盪發生，靜態電流為9.946uA
　　增益提升放大器利用放大器與曡接式放大器組合使輸出阻抗增加，進而提高增益，增益為112.8db，單位增益頻寬為171.0MHz，相位餘裕為87.52度。
　　溫度感測電路由放大器、BJT元件以及施密特觸發器所構成，透過與溫度相關的電流以及施密特觸發器產生能夠隨溫度變化而改變的工作週期方波，電源電壓為1.8V，工作溫度-40℃~120℃，電源敏感度1.478 ℃/V，最佳精準度為0.0432℃(-40℃~50℃)，功耗為101.1uW。

關鍵字

低於1伏特帶隙參考電壓電路 ； 低壓差線性穩壓器 ； 增益提升放大器 ； 溫度感測電路

並列摘要

This paper combines the design of power management chips and sensor systems, and learns various design skill and measurement methods through different circuit designs, including sub-1V bandgap reference voltage circuit, low-dropout linear regulator, gain boosted Amplifier and temperature sensing circuit. These circuits are all designed using the 0.18um 1.8V 3.3V 1P6M CMOS process provided by Taiwan Semiconductor Research Institute.

The power supply voltage of the sub-1V bandgap reference voltage circuit is 1V. The temperature characteristics of the BJT are used to generate positive and negative temperature coefficients. After linear combination, the temperature parameters are cancelled. Produces an output voltage independent of temperature. The output voltage generated at -40℃~125℃ is 597~601mV, and the power consumption is 44.34uW.

The power supply voltage of the low dropout linear regulator is the input voltage. The input range can be 1.2V to 3.3V. The feedback voltage comes from the feedback resistors. The feedback voltage is compared with the reference voltage by error amplifier. Then, it sent the signal to the pass transistor for stabilizing output voltage at 1V. The line regulation is 0.01%. The load regulation is 0.62%. There is no oscillation when switching between light and heavy loads. The quiescent current is 9.946uA

The gain boosted amplifier uses folded cascade amplifier to increase the output impedance and also increase gain. The gain is 112.8db, the unity gain bandwidth is 171.0MHz, and the phase margin is 87.52 degrees.

The temperature sensing circuit is composed of amplifiers, BJT elements and Schmitt trigger. Through temperature-related currents and Schmitt trigger, it generates a duty cycle square wave that can change with temperature. The power supply voltage is 1.8V. The sensing temperature is -40℃~120℃, the power sensitivity is 1.478 ℃/V, the best accuracy is 0.0432℃ (-40℃~50℃), and the power consumption is 101.1uW.

並列關鍵字

bandgap reference voltage circuit ； low dropout linear regulator ； gain boosted amplifier ； temperature sensing circuit

參考文獻

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