SAR ADC中高能效电荷均值开关方法

提出一种逐次逼近型模数转换器（successive approximation register analog-to-digital converter，SAR ADC）高能效电荷均值开关方法。该方法能够提供恒定的共模电压VCM，大小为VREF的一半，且只需要使用两个参考电压VREF和地，避免了额外的电压基准电路。为了增加一位精度并保持恒定的共模电压，C-2C结构替代参考电容C。与单调开关方法相比，该方法能耗减少66.65％，电容面积减少49.41％。行为仿真结果证明了该方法的有效性。

Energy-efficient charge-average capacitor switching scheme for SAR ADC

An energy-efficient charge-average capacitor switching scheme was proposed for successive approximation register analog-to-digital converters (SAR ADCs). The charge-average technique ensures constant common-mode voltage VCM, which is VREF/2. Thus, only two reference voltages, VREF and ground, are utilized，avoiding extra circuit for generating references. Besides, to add one more bit precision and to keep common-mode voltage constant, a dummy capacitor is realized by C-2C structure instead of unit capacitor C. As a result, the proposed switching technique can save energy by 66.65％ and reduce capacitor area by 49.41％, respectively, compared to the monotonic switching scheme. Behavioural simulation results indicate that the proposed switching scheme is effective.