← 返回 JSSC 论文列表JSSC 2012第11期Analog Circuits0.18μm
A 0.5-V R-MOSFET-C Filter Design Using Subthreshold R-MOSFET Resistors and OTAs With Cross-Forward Common-Mode
0.5V低功耗高线性度可调谐R-MOSFET-C滤波器设计
0.18μm CMOS, 0.5V, 91-268kHz可调, 61.0dB动态范围, 0.6mW
亚阈值R-MOSFET-C滤波器低电压线性电阻动态范围
▸创新点1：亚阈值R-MOSFET线性电阻技术，通过利用晶体管亚阈值工作区实现高线性电阻特性，解决了传统MOSFET电阻在低压（0.5V）下非线性严重的问题，其总谐波失真（THD）控制在1%以内。
▸创新点2：交叉前馈共模消除OTA设计，采用独特的共模信号抵消技术，显著提升了运算跨导放大器（OTA）的共模抑制比（CMRR），在0.5V超低电源电压下仍保持53.7dB的无杂散动态范围（SFDR）。
▸创新点3：片上PLL自动带宽调节系统，集成锁相环（PLL）实现滤波器带宽（91kHz-268kHz）的3:1动态调节，无需外部控制，功耗仅0.6mW，体现了系统级低功耗设计创新。
▸创新点4：全集成0.5V R-MOSFET-C滤波器架构，结合亚阈值电阻与改进OTA，在0.18μm CMOS工艺下实现61dB动态范围，突破了传统有源滤波器在超低压下的性能限制。
Abstract
A 0.5-V fully integrated R-MOSFET-C filter with low power, good linearity, and wide frequency tunability is demon- strated. It relies upon the operational transconductance ampli fier using the cross-forward common-mode cancellation and the linear sub-threshold R-MOSFET resistor—both employ subthreshold operation of the transistors. A fifth-order Chebys hev low-pass filter using regular transistors with a 0.5-V threshold voltage in a 0.18- m triple-well CMOS process is implemented for a 0.5-V supply. The filter’s bandwidth can be tuned from 91 to 268 kHz, which is almost a 3-to-1 tuning ratio. At a nominal bandwidth of 135 kHz automatically set by the on-chip PLL circuit, the dynamic range is at 61.0 dB for 1% total harmonic distortion, while the spurious-free dynamic range under two-tone signals is at 53.7 dB. The total current and power consumptions including bias circuits are 1.2 mA and 0.6 mW, respectively.