一种新型带宽自动校准有源低通滤波器  

A Novel Active Low-pass Filter with Automatic Calibration of Bandwidth

作　　者：李航标 LI Hangbiao(Southwest China Institute of Electronic Technology,Chengdu 610036,China)

机构地区：[1]中国西南电子技术研究所,成都610036

出　　处：《电讯技术》2021年第10期1308-1315,共8页Telecommunication Engineering

摘　　要：为了消除工艺、电压、温度(Process,Voltage,Temperature,PVT)波动及老化对片上集成有源滤波器带宽的影响,提出了一种新型带宽自动校准有源低通滤波器。通过时域采样有源低通滤波器对输入的响应,并与参考电压进行比较,算法电路根据比较结果调整滤波器电容大小,自动搜索到最佳的滤波器带宽。为了消除带宽校准过程中电路响应延迟对校准精度的影响,在时钟及其二分频信号控制下分别执行一次校准,然后通过倍乘和减法运算得到最终对PVT波动、老化及电路响应延迟均不敏感的精确的滤波器带宽。在65 nm互补金属氧化物半导体(Complementary Metal Oxide Semiconductor,CMOS)工艺下设计了一款带宽自动校准有源低通滤波器,仿真结果显示其低频增益为67 dB,在8~50 MHz带宽范围内带宽校准误差在0.7%以内。To eliminate the influence of process,voltage,temperature(PVT)fluctuations and aging on the bandwidth of the on-chip integrated active filter,a novel active low-pass filter(LPF)with automatic calibration of bandwidth is proposed.By sampling the response of the active LPF to the input in time domain and comparing it with the reference voltage,the algorithm circuit adjusts the size of the filter capacitor according to the comparison result,and automatically searches for the optimal filter bandwidth.To eliminate the influence of the circuit response delay on the calibration accuracy during the process of bandwidth calibration,the calibration is performed once under the control of the first clock and is performed twice under the control of the second clock whose frequency is half of the first clock respectively,and then the final accurate filter bandwidth that is insensitive to PVT fluctuations,aging and circuit response delay is obtained by multiplication and subtraction operations.A bandwidth auto-calibration active LPF is designed under 65 nm complementary metal oxide semiconductor(CMOS)process.The simulation shows that the low-frequency gain of the filter is 67 dB,and the calibration error is within 0.7%in the bandwidth range of 8~50 MHz.

关 键 词：有源滤波器 低通滤波器 带宽校准 互补金属氧化物半导体 PVT波动 

分 类 号：TN713[电子电信—电路与系统]