← 返回 JSSC 论文列表JSSC 2007第8期Analog Circuits0.18μm
Design of Low-V oltage Highly Linear Switched-R-MOSFET-C Filters
设计低电压高线性开关R-MOSFET-C滤波器，采用占空比控制调谐实现高线性。
0.18μm CMOS, 0.6V, 77dB THD@0.6V, 90dB THD@0.8V
低电压高线性开关R-MOSFET-C占空比调谐CMOS滤波器
▸创新点1：采用占空比控制调谐技术（方法创新），通过时间域调谐而非电压域调谐，实现了在低电源电压（0.6V）下的高线性度（THD <77 dB），且调谐范围不受电源电压限制。
▸创新点2：将MOSFET完全导通并置于滤波器反馈环路内（电路创新），显著降低非线性电阻的影响，使导通电阻远小于线性滤波器电阻，从而在0.8V电源下实现THD <90 dB的超低失真。
▸创新点3：提出低电压（0.6V）与高线性度协同设计（系统创新），通过优化开关MOSFET的时序和反馈结构，在1mW功耗和0.7mm²面积内实现高性能滤波，突破传统电压-线性度权衡限制。
▸创新点4：采用0.18μm CMOS工艺实现（工艺创新），验证了该设计在先进制程下的可行性，为低电压模拟电路集成提供可扩展方案。
Abstract
This paper discusses the design, analysis and per- formance of a low-voltage, highly linear switched-R-MOSFET-C filter. High linearity, even at a low supply voltage, is achieved through the use of duty-cycle-controlled tuning. Tuning MOS- FETs are switched completely on while conducting, such that their nonlinear resistance is much smaller than the linear filter resistors, resulting in low distortion. The MOSFETs are also placed inside the filter feedback loop which further reduces distortion. Because tuning is done in the time domain, rather than in the voltage domain, the tuning range is independent of the supply voltage. The filter achieves 77 dB total harmonic distortion (THD) using a 0.6-V supply, and 90 dB THD using a 0.8-V supply, with a 0.6-Vpp differential 2 kHz sine input. The prototype IC, imple- mented in a 0.18- m CMOS process, occupies an area of 0.7 mm/50 and consumes 1 mW of power from a 0.6-V supply.