用於PRML讀取通道之七階低通濾波器

Abstract

本篇論文描述一個利用電流模式設計之低電壓低通濾波器。利用電流模式積分器組成一個Biquad電路，使截止頻率提升為680百萬赫茲，一般的Biquad電路主要由兩個區塊所組成，分別為lossy 及lossless差動積分器，可藉由改變偏壓電流來改變濾波器的截止頻率。此電路在2.5伏特的電源下工作，其消耗功率約為3.76毫瓦。使用0.25微米互補金氧半製成。

Low voltage CMOS low pass filter using current-mode techniques is presented. The 680NHz cutoff frequency is achieved by using current-mode integrator as a building block of the current-mode biquad. A universal biquad is constructed from two basic building blocks, lossless and lossy differential current-mode integrators. Tuning of the biquad is obtained by changing the bias currents. The power consumption is 3.76mW with 2.5V supply voltage. The chip is fabricated in 0.25μm CMOS process.