光通訊類比前端積體電路設計

Abstract

本計畫將針對850nm 高速乙太網路光通訊系統應用，以標準CMOS 製程技術 開發其接收端與發射端最關鍵的類比前端積體電路，其接收端包含檢光二極體、轉 阻放大器、限幅放大器、以及可提供補償功能的等化器等，其發射端則主要為一雷 射驅動器，此類比前端積體電路之性能乃是整個光纖網路系統性能的重要瓶頸。在 各種放大器之設計上本計畫將運用負阻抗補償技術以求同時改善增益與頻寬兩者 之性能；此外，為補償CMOS 檢光二極體之非理想頻率響應特性，本計畫將結合適 應性等化器之設計架構，以實現自動最佳化補償之功能，並可藉此降低因製程、電 壓、或是溫度變化所造成之性能劣化。關於雷射驅動器部分，其主要研究工作則著 重於自動功率控制功能之數位化設計、以及適用於低電壓CMOS 製程之主動式阻抗 匹配技術之開發。本計畫之最終目的為開發出可適用於continuous-mode 與 burst-mode 系統之整合型光接收器與高整合度之雷射驅動器。

The goal of this project is to develop the analog front-end ICs for 850nm optical transceiver used in high-speed Ethernet optical networks by using CMOS technology. To build an ideal optical receiver, functional blocks such as the photodiode, the transimpedance amplifier, the limiting amplifier and the adaptive equalizer for compensation purpose, are integrated together. The laser driver is the core circuit for building an optical transmitter. In general, the overall system performance is dominated by these analog front-end ICs. For amplifiers design, the negative impedance compensation technique will be used to improve both the gain and the operating bandwidth simultaneously. To automatically compensate the high-frequency rolling off due to the nonidealities in the photodiode, an adaptive equalizer will be quite helpful. This design is also capable of reducing the performance degradation due to possible PVT variations. As for the laser driver, our major research efforts will be focused on the development of design schemes for both the digital automatic power control and the low-voltage active back-termination. The final target of this project is to deliver both a highly-integrated 850nm optical receiver and a highly-integrated laser driver for both continuous-mode and burst-mode applications.