In this letter, a VAQ-based DAC switching scheme is proposed to improve the power efficiency of SAR ADCs. The input signals are sampled onto the bottom-plates of the most significant bit (MSB) capacitors, thereby eliminating the reset energy. The reference voltage VCM rath than VREF is switched during the third-bit cycle, thereby significantly reducing the power consumption. Additionally, an energy-efficient one-sided switching technique is employed from the fourth-bit cycle. This proposed switching scheme achieves a 99.51% reduction in switching energy over the classic scheme.