輸出時脈週期的變化（稱為抖動）通常是鎖相迴路的重要指標。在本論文中，我們提出「抖動測量方法」和「嚴密的測試流程」來檢查鎖相迴路在各種情況下都有一定的可靠性。「抖動測量方法」主要的功能為 — 基於抖動的校準。使用極大極小時間數位轉換器 (min-MAX Time-to-Digital)，我們可以即時記錄最小周期代碼和最大周期代碼，最小周期代碼和最大周期代碼的差值表示峰對峰值抖動量代碼，通過提出的基於抖動的校準，我們可以進一步將平均峰對峰值抖動量代碼映射到其相應的絕對峰對峰值抖動量，單位為皮秒。
下一步是達成目標：識別在惡劣操作環境下可能發生故障的脆弱裝置。我們提出「嚴密的測試流程」可以測量在模擬惡劣操作環境下其鎖相迴路的性能。其獨特的功能 — 透過抖動測量方法進而得到溫度對應電壓之映射方法。在測試流程結束時，將峰對峰值抖動量作為「穩健性指標」來篩選是否為脆弱裝置。
我們在90nm CMOS製程上實施基於鎖相迴路提出的測試流程，「抖動測量方法」的後仿真模擬顯示：我們不僅可以檢測到傳統基於採樣的方法無法得到的短時瞬態誤差，而且還可以得到準確的絕對峰對峰值抖動量，以達成在線抖動驗證的目的；無法通過簡單的傳統測試來辨別脆弱裝置的疑慮可以透過我們提出「嚴密的測試流程」來解決。

Regarding a Phase-Locked Loop (PLL), the change of its output clock period known as jitter is often an important metric. In this thesis, we propose a “jitter measurement scheme” and “rigorous test flow” to check the robustness of a PLL. Our “jitter measurement scheme” has a unique feature – A Dithering-Based Calibration. With the min-MAX Time-to-Digital Converter (called min-MAX TDC), we be able to derive both the minimum period code and the maximum period code recorded in a monitoring session on the fly, and their difference denotes a Peak-to-Peak Jitter Amount (PPJA) code. With the proposed Dithering-Based Calibration, we can further map the average PPJA code (avg-p-code) into its corresponding absolute PPJA in picoseconds.
The further goal is to identify weak devices that could fail under hostile operating conditions. We devise a “rigorous test flow” to measure the performance of a PLL device with “mimicked” hostile operating conditions. Its unique feature – A temperature-to-VDD-mapping scheme based on our jitter measurement scheme. At the end of the test, the peak-to-peak jitter is used as a “robustness indicator” to guide the screening process of weak devices.
We have implemented the proposed method for an in-house cell-based PLL using a 90nm CMOS process. The post-layout simulation of “jitter measurement scheme” demonstrates that we can not only detect some short-time transient errors that could have escaped a traditional sampling-based method, but also report an accurate absolute peak-to-peak jitter amount to serve the purpose of online jitter validation. The results of “rigorous test flow” obscure symptoms that might have escaped a simple traditional test can now be revealed.

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