新型基于源极跟随器的零极点型滤波器  

Novel Zero-Pole Type of Filters of Source-Follower-Based Bi-Quad Cell

作　　者：陈勇[1] 周玉梅[1] 

机构地区：[1]中国科学院微电子研究所,北京100029

出　　处：《半导体技术》2010年第3期295-298,共4页Semiconductor Technology

摘　　要：提出一种新型基于源极跟随器的零极点型滤波器。提出的单支路全差分的双二阶单元采用两个前馈电容综合复数零点,用于实现连续时间零极点型滤波器。源极跟随器在电压域直接处理信号使得该双二阶单元以低功耗实现高线性度。利用CMOS0.18μm工艺级联实现了一个4阶切比雪夫Ⅱ型全差分低通滤波器。测试结果表明,滤波器带宽为2.75MHz,实现了带外下陷特性。在2V电源电压下,消耗电流为1.5mA,测得带内IIP3为5dBm。在三次谐波失真(HD3)为-46.3dB条件下滤波器的动态范围为65dB。Novel source-follower-based bi-quad cell was presented. By using two forward capacitors, the proposed cell synthesizes complex zeros with a single branch fully differential structure, and it is used in continuous time zero-pole type filter. The proposed cell exhibits high linearity with low power consumption because the source follower processes the signal directly in the voltage domain. A 4th-order Chebychev II fully differential low-pass filter was fabricated in CMOS 0.18μm technology. The test results demonstrate that the bandwidth is 2.75 MHz, and implement out-of-band notch characteristic. It provides 5 dBm in-band ⅡP3, while draining an average 1.5 mA from 2 V. The dynamic range of the filter is 65 dB with - 46.3 dB HD3.

关 键 词：基于源极跟随器型双二阶单元 切比雪夫Ⅱ型滤波器 互补型金属氧化物晶体管 

分 类 号：TN402[电子电信—微电子学与固体电子学]