十四位元三億取樣頻率之電流汲取式數位類比轉換器

Abstract

近年來，由於積體電路的製程發展迅速，促使著行動通訊發展越發茁壯，在第四代行動通訊已經盛行的現在，促成行動通訊裝置已經成為生活必需品。毫微微蜂巢式基地台(femtocell)的出現，增加了通訊信號的覆蓋率以維持良好的傳輸品質。為了構築一台能夠準確傳遞封包的毫微微蜂巢式基地台，一個高解析且高頻寬的數位類比轉換器的設計是很重要的。

本篇論文使用電流汲取式數位類比轉換器來達成所需的十四位元解析度與三億赫茲取樣頻率，而此十四位元電流式數位類比轉換器採用分段式(Segmented)架構，此架構以兩塊六位元的溫度計碼(Thermometer-based)轉換器與二位元二進制碼(binary-weighted) 轉換器所組成。此電路採用台積電TSMC 0.18 μm 1P6M mixed-signal CMOS 製成完成，類比與數位的供應電源分別採用 1.8 V 與 1 V。電路量測結果，最大 SFDR 能夠達到 44.72 dB，而整體消耗功率為 23.52 mW。

In the recent years, because the technology of integrated circuits develop rapidly, it improves the technique of mobility communication. Nowadays, the fourth generation of mobile communication has become popular, and mobile communication devices have become a necessity. The emergence of femtocells has increased the coverage of communication signals to maintain good transmission quality. In order to construct a femtocell base station capable of accurately transmitting packets, the design of a high resolution and high sample frequency digital-to-analog converter is very important.

In this paper, a 14-bit 300MHz digital-to-analog converter is achieved by current-steering architecture, and this 14-bit circuit consists of three segments. Two of it is a 6-bit thermometer-based converter, and the other is a 2-bit binary-weighted converter. The supply voltage in analog and digital is applied in 1.8 V and 1 V, respectively. From the measurement results, a peak SFDR of 44.72 dB is achieved in TSMC 0.18μm 1P6M mixed-signal CMOS, and the power consumption is 23.52 mW.