In this letter, a capacitor-splitting switching algorithm for successive approximation register (SAR) analog-to-digital converters is proposed. To achieve low power, the hybrid switching scheme is involved. The monotonic switching technique is used during the last bit cycle; for other bit cycles except the first one, the switching is based on MSB and the former determined bit. Besides, the common-mode voltage remains constant during the entire bit cycles except the last one. In addition, the proposed capacitor-splitting switching process is easily performed, relaxing the design complexity of the SAR control logic. As a result, the proposed switching scheme is a better trade-off among energy-efficiency, common-mode voltage variation, and logic complexity.

在这封信中，提出了一种用于逐次逼近寄存器（SAR）模数转换器的电容器拆分开关算法。为了实现低功耗，需要使用混合开关方案。在最后一个比特周期内使用单调切换技术。对于除第一个比特周期外的其他比特周期，切换基于MSB和前一个确定的比特。此外，共模电压在除最后一个比特周期外的整个比特周期内保持恒定。此外，所提出的电容分路切换过程很容易执行，从而缓解了SAR控制逻辑的设计复杂性。结果，所提出的开关方案是在能量效率，共模电压变化和逻辑复杂度之间更好的权衡。