An　ultra-low　power　dual-CDAC　switching　strategy　applied　in　SAR　ADC　is　proposed.　This　switching　scheme　adopts　two　sub-CDAC　structures.　The　first　CDAC　switching　adopts　the　CDAC　selection　mode,　and　the　subsequent　first　conversion　adopts　the　overall　reference　voltage　switching　to　realize　the　maximum　two-bit　quantization　without　power　consumption.　The　subsequent　switch　only　involves　the　capacitance　in　a　single　position　of　a　single　CDAC,　which　is　simpler　to　switch,　and　the　capacitance　ratio　on　each　CDAC　is　reduced　by　using　a　dual　CDAC.　The　total　capacitance　is　reduced　from　2^N-1　to　2^N-2,　and　the　use　of　Vcm　as　the　intermediate　reference　voltage　can　achieve　lower　switching　power　consumption　than　the　existing　research　literature,　and　the　same　unit　capacitance　under　the　premise　of　N-bit　resolution　requires　less　total　CDAC　capacitance,　reducing　the　area　overhead.　Through　numerical　simulation　analysis,　The　proposed　switching　structure　is　reduced　by　97.7%　and　area　of　proposed　CDAC　structure　is　optimized　by　75%,　which　compared　with　traditional　CDAC　switching.　©　2024　IEEE.