适用于中频采样的CMOS自举采样开关  

CMOS Bootstrapped Circuit Suitable for IF Sampling

作　　者：钱宏文[1] 朱燕君[1] 季惠才[1] 陈珍海[1] 

机构地区：[1]中国电子科技集团公司第58研究所,江苏无锡214035

出　　处：《中国电子科学研究院学报》2013年第2期209-212,共4页Journal of China Academy of Electronics and Information Technology

摘　　要：分析了影响CMOS采样开关性能的非理想因素,针对中频采样A/D转换器对采样开关特性的要求,改进得到了一种新型的CMOS自举采样开关。较之传统栅压自举开关,此新型MOS采样开关能够消除由于阈值电压随输入信号变化所产生的非线性。基于0.18μm标准CMOS数模混合工艺对电路进行了模拟,模拟结果显示,在输入信号为2.39 MHz正弦波,峰峰值为2 V,采样时钟频率为100 MHz时,开关的无杂散动态范围达到116.7 dB,较之传统自举采样开关提高了15dB左右。试验结果表明该栅增压电路非常适用于高速中频采样。The major factors that affect the performance of a CMOS analog sampling switch is discussed. A new bootstrapped circuit to decrease the on-resistance independent of input signal dependence and bulk effect is proposed. This switch not only eliminates the nonlinearity introduced by gate-source voltage variation, but also reduces the nonlinearity resulting from threshold voltage variation. The entire circuit is simulated in 0.18 um standard CMOS AMS process. The proposed sampling switch achieves a spurious free dynamic range of 116.7 dB for a 2.39 MHz ,2 V Vp-p input signal, sampled at a rate of 100 MS/s. This method is especially useful for high speed high resolution IF sampling ADCs.

关 键 词：模数转换器 中频采样 栅压自举开关 MOS开关 

分 类 号：TN792[电子电信—电路与系统]