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Title: | 具數位補償之低溫度係數弛張振盪器 Low TC Relaxation Oscillators with Digital Compensation |
Authors: | Yi-An Chang 張亦安 |
Advisor: | 劉深淵(Shen-Iuan Liu) |
Keyword: | 數位補償,持張振盪器, Digital compensation,relaxation oscillator, |
Publication Year : | 2017 |
Degree: | 碩士 |
Abstract: | 這篇論文利用數位校正迴路改進兩個弛張式振盪器。第一個振盪器利用抗抖動技術達成較佳的相位雜訊。數位校正迴路用以校正NMOS閘極源極電壓的溫度變異。此外也實現晶載參考電壓以避免外給參考電壓。此振盪器在1.2V供應電壓下消耗157.8μW。量測的平均振盪頻率為13.4MHz。有無校正的振盪頻率溫度係數分別為193.15和1098.7ppm/○C,改善5.7倍。在100kHz偏移頻率下的相位雜訊優值為-154.4dB。
第二個振盪器利用兩個數位校正迴路調整振盪器的參考電壓,使振盪頻率與比較器延遲無關,避免其造成溫度變異。由於補償後的振盪頻率與電阻阻值相關,利用組合電阻降低此阻值的溫度係數。量測的平均振盪頻率為943.1kHz。此振盪器在0.9V供應電壓下消耗5.2μW。有無校正的振盪頻率溫度係數分別為93.88和618.17ppm/○C,改善6.6倍。在-10~100°C間的頻率變異小於±0.7%。振盪頻率隨供應電壓變化的敏感度為4.37%/V。 Two relaxation oscillators with digital compensation loops are presented in this thesis. The first design is a relaxation oscillator exploiting anti-jitter technique to achieve great phase noise performance. The digital compensation loop is introduced to compensate the temperature variation of the gate-source voltage of an NMOS transistor. On-chip voltage references are realized, avoiding any off-chip voltage reference. Consuming 157.8μW under a 1.2V supply, the oscillator has an average frequency of 13.4MHz. The measured TCs of the oscillation frequency with and without compensation are 193.15 and 1098.7ppm/○C, demonstrating a 5.7× improvement. The figure of merit with respect to phase noise is -154.4dB at 100kHz offset frequency. The second design utilizes two digital compensation loops (DCLs) to adjust the reference voltage of the oscillator in order to make the oscillation frequency independent of the comparator delay, which would cause temperature variations. Since the compensated oscillation frequency is dependent on a resistance, the parallel/series composite resistors are implemented to minimize the temperature coefficient of the resistance. The measured average oscillation frequency is 943.1kHz. The whole oscillator consumes 5.2μW under a 0.9V supply. The measured TCs of the oscillation frequency with and without compensation are 93.88 and 618.17 ppm/○C, respectively. It achieves a TC improvement of 6.6×. The measured frequency variation is within ±0.7% from -10○C to 100○C by using the DCLs. The measured line sensitivity is 4.37%/V. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/19974 |
DOI: | 10.6342/NTU201801737 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 電子工程學研究所 |
Files in This Item:
File | Size | Format | |
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ntu-106-1.pdf Restricted Access | 3.2 MB | Adobe PDF |
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