應用於光接收機之低功耗接收信號強度指標及製程與溫度變異補償方法

Low Power CMOS RSSI for Optical Receiver and A Compensation Method for Process and Temperature Variations

施泓仰(Hung-Yang Shih)

指導教授 ： 曹恆偉

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.10894

摘要

時至今日，大量資料已透過乙太網路傳輸，然而在乙太網路規格中，對於備援與自癒機制的規範不多，所以在實體層須有信號監測功能。
接收信號強度指標為信號監測的方法之一，這篇論文探討並設計兩個版本的接收信號強度指標電路，兩者皆以0.18 um 1P6M CMOS製程製造。第一個版本的接收信號強度指標是一個低功耗對數放大器，基於傳統片段線性近似對數放大器的原理，設計了新穎的循環式對數放大器，並使用斬波電路消除直流徧移與閃爍雜訊，在30 dB的動態範圍下，線性誤差為 ±1.1 dB，消耗功率1.13 mW，且在 〖-20〗^o C 到 〖50〗^o C 的溫度範圍內有+4/-2 dB的偏差。
第二個版本的接收信號強度指標是一個80 dB具有製程與溫度補償的對數放大器。一個高線性度的限幅放大器被設計並使用在這個對數放大器中，以達到更大的動態範圍。為了在製程和溫度(-20^o C~〖70〗^o C)的變異下，得到一致的輸出結果，分別利用加法器與可變增益放大器來平移與旋轉對數放大器的特性曲線。模擬結果顯示線性誤差為 ±0.9 dB，製程和溫度變異造成的偏差為+1/-1.6 dB，而電路消耗了1.55 mW的功率。

關鍵字

接收信號強度指標 ； 光接收機 ； 光二極體 ； 對數放大器 ； 互補式金氧半場效電晶體 ； 低功耗 ； 製程與溫度補償

並列摘要

The Ethernet transmits a lot of data nowadays, but back-up or self-healing mechanism is not much specified in the Ethernet standard. Signal monitoring is necessary in the physical layer.
Received signal strength indication (RSSI) is one of the methods to monitor signal quality. Two versions of RSSI are investigated and designed in this thesis. Both are fabricated in 0.18 μm 1P6M CMOS process. The first version is a low power logarithmic amplifier. Based on the traditional piecewise linear logarithmic amplifier, we design a novel cyclic logarithmic amplifier, and reduce its DC offset and flicker noise by using a chopper. With 30 dB dynamic range and ±1.1 dB linearity error, it consumes 1.13 mW. Temperature ranging from 〖-20〗^o C to 〖50〗^o C induces +4/-2 dB variation.
The second version is a 80 dB logarithmic amplifier with process and temperature compensation. A high linearity limiting amplifier is designed for this logarithmic amplifier to achieve wide dynamic range. An adder and a variable gain amplifier separately shifts and rotates the characteristic curve of the logarithmic amplifier to get consistent output under process and temperature variation (-20^o C~〖70〗^o C). Post-layout simulation shows that the linearity error is ±0.9 dB with process and temperature variation induced error of +1/-1.6 dB. The power consumption is 1.55 mW.

並列關鍵字

RSSI ； optical receiver ； photo diode ； logarithmic amplifier ； CMOS ； low power ； temperature and process compensation

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