Non-binary SAR ADC with Digital Compensation of Comparator Offset Effect -- *
Non-binary SAR ADC with Digital Compensation of Comparator Offset Effect -- *
复制标题
具有比较器偏移效应数字补偿功能的非二进制 SAR ADC -- *
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
San Hao
中科院分区：
文献类型：
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作者：
Ogawa Tomohiko;Mtsuura Tatsuji;Kobayashi Haruo;T. Nobukazu;Hotta Masao;San Hao
jp摘要本文描述了使用纠错非二进制逐次逼近算法创建低功耗SAR ADC的技术：（1）我们提出了一种具有两个动态比较器的非二进制SAR ADC;第一转换级使用低功耗高噪声比较器，最后一级使用噪声较低但功耗较高的第二比较器。由于第一转换级的高噪声以及两个比较器之间的运算集不匹配而产生的比较器判决误差，通过纠错非二进制逐次逼近算法进行数字校正。(2)为了实现低功耗，采用二进制逐次逼近算法的电荷共享SAR ADC将是有吸引力的。然而，ADC中的比较器组降低了ADC的线性度，并且该比较器组通常通过模拟方法来校准。在这里，我们提出了一种电荷共享SAR ADC的纠错非二进制算法，并与数字校正的比较器的OKSET，所以模拟校准是不需要的。(3)我们还提出了一种具有两个动态比较器的非二进制电荷共享SAR ADC，它是（1）和（2）的组合。这使得进一步的低功耗实现成为可能，而无需模拟校准。
jp Abstract This paper describes techniques for creating a low-power SAR ADC with an error-correcting non-binary successive approximation algorithm: (1) We propose a non-binary SAR ADC with two dynamic comparators; a low-power high-noise comparator for the first conversion stages, and a second comparator with lower noise but higher power consumption for the last stages. Comparator decision errors – due to the high noise of the first conversion stages, and offset mismatch between the two comparators – are digitally corrected by the error-correcting non-binary successive approximation algorithm. (2) For realizing low power consumption, a charge-sharing SAR ADC using a binary successive approximation algo-rithm would be attractive. However the comparator offset in the ADC degrades the ADC linearity, and this offset is usually calibrated by an analog method. Here we propose a charge-sharing SAR ADC with an error-correcting non-binary algorithm, and with digital correction of comparator offset, so that analog calibration is not required. (3) We also propose a non-binary charge-sharing SAR ADC with two dynamic comparators, which is the combination of (1) and (2). This makes further low power implementation possible without analog calibration.