This thesis presents a new scheme of designing a low power 12-bit split capacitor array analog to digital converter (ADC). The proposed design involves a novel way so as to achieve low power and low area requirements. The design is targeted to cater the needs of micro sensor wireless applications. Low Power consumption is reported with moderate accuracy. In this thesis the design strategies for power effective medium/high resolution successive-approximation ADC are analyzed. The study considers reducing the power of the capacitive array with suitable capacitive attenuators that do not need non-unity capacitors. The design of minimum power comparators is analyzed and a novel comparator scheme, named time-domain comparator, is described. The input referred offset voltage of the time domain comparator reported is 70011v. The increase of resolution with reduced sampling is also analyzed and implemented. The different architectures of the Boot strapping were implemented to reduce the distortion of the sampling switch. The proposed methodologies, verified with a test design, are capable to provide 12-bit with 50-kHz signal band and 1-V supply. All the circuits in this work are implemented using Intel's 32 nm CMOS process