应用于高速高精度流水线ADC中的差分参考源  

A differential reference voltage source used in high-speed high-precision pipelined ADC

作　　者：尹勇生[1] 杨鑫波[1] 邓红辉[1] 

机构地区：[1]合肥工业大学微电子设计研究所,合肥230009

出　　处：《电子测量与仪器学报》2012年第12期1043-1049,共7页Journal of Electronic Measurement and Instrumentation

基　　金：国家自然科学基金(61076026)资助项目

摘　　要：在流水线ADC中,参考电压源的波动将会影响其转换精度,针对流水线ADC中MDAC(multiplying D/A converter)和subADC对参考源精度的不同要求,设计了一种改进的差分参考源产生及其缓冲电路,分别给MDAC和subADC提供参考源并分别设计输出缓冲器,减小MDAC和subADC参考源间的相互影响。设计可编程偏置电路,可根据实际工作时钟频率灵活控制电流大小,并设计电荷泵升压模块和无源滤波器模块,保证低压下电路能顺利获得高精度的接近电源电压的参考源电平。Spectre后仿真结果表明,参考源最小功耗15 mW,此时建立时间5.842 ns;最大功耗58 mW,此时建立时间1.036 ns,可以满足14位最高时钟频率分别为80MSPS和450MSPS流水线ADC的要求。An analysis of performance degradation due to the fluctuation of reference voltage for pipelined ADC is presented in this paper. For the MDAC （multiplying D/A converter） and subADC in pipelined ADC have very different requirements for the precision of reference voltage, an improved differential reference voltage source and its buffer circuit is proposed. The reference voltage for MDAC and subADC are provided and designed the output buffer separately, so that to reduce the interaction between MDAC and subADC. With the help of programmable bias circuit, the bias current can be flexible controlled. Also, the modules of charge pump and passive filter are designed to help to get the high-precision reference voltage which is close to the supply vokage. Spectre post-layout simulation results show that the reference source has the minimum power of 15 mW, and the entire set-up time is 5.842 ns; has the maximum power of 58 mW, and the entire set-up time is 1.036 ns. The reference source can meet the requirement of 14-bit 80MSPS to 450MSPS pipelined ADC.

关 键 词：流水线ADC 参考源 建立时间 

分 类 号：TN402[电子电信—微电子学与固体电子学] TN431.1