Non-ideal effects of MOS capacitor in a switched capacitor waveform recorder ASIC
Non-ideal effects of MOS capacitor in a switched capacitor waveform recorder ASIC
复制标题
开关电容波形记录器 ASIC 中 MOS 电容的非理想效应
DOI：
10.1088/1674-1137/40/7/076102
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发表时间：
2016
影响因子：
3.6
通讯作者：
Yi
中科院分区：
文献类型：
--
作者：
H. Zhang 章;Z. Deng 邓;Yi
SCAs（开关电容器阵列）具有广泛的用途，特别是在高能物理、核科学和天体物理实验中。本文提出了一种利用MOS电容作为采样电容，在SCA设计中以小电容面积获得大电容的方法。研究了MOS电容器的非理想效应，并提出了减少这些不利影响的方法。设计了一个使用MOS电容存储样品的SCA ASIC原型，并进行了测试以验证该方法。SCA集成了32个通道，每个通道有64个单元和一个读出放大器。存储电压被转换成一对差分电流（±4 mA最大值）并复用到输出。所有功能都已经过验证。功耗小于2mw /ch。同一通道内所有细胞的INL均优于0.39%。经过测试，SCA的等效输入噪声为2.2 mV，输入为625 kHz全尺寸正弦波，采样频率为40 MSPS（每秒百万采样），读取频率为5 MHz。考虑1v动态范围，有效分辨率为8.8位。最大采样率高达50 MSPS，读出速率为15 MHz，噪声小于2.5 mV。测试结果验证了MOS电容的可行性。
SCAs (Switched Capacitor Arrays) have a wide range of uses, especially in high energy physics, nuclear science and astrophysics experiments. This paper presents a method of using a MOS capacitor as a sampling capacitor to gain larger capacitance with small capacitor area in SCA design. It studies the non-ideal effects of the MOS capacitor and comes up with ways to reduce these adverse effects. A prototype SCA ASIC which uses a MOS capacitor to store the samples has been designed and tested to verify this method. The SCA integrates 32 channels and each has 64 cells and a readout amplifier. The stored voltage is converted to a pair of differential currents (±4 mA max) and multiplexed to the output. All the functionalities have been verified. The power consumption is less than 2 mW/ch. The INL of all the cells in one channel are better than 0.39%. The equivalent input noise of the SCA has been tested to be 2.2 mV with 625 kHz full-scale sine wave as input, sampling at 40 MSPS (Mega-samples per Second) and reading out at 5 MHz. The effective resolution is 8.8 bits considering 1 V dynamic range. The maximum sampling rate reaches up to 50 MSPS and readout rate of 15 MHz to keep noise smaller than 2.5 mV. The test results validate the feasibility of the MOS capacitor.