Ultra-Low Power, Area Optimized CMOS Successive Approximation Based ADC for Mixed-Signal Systems

Analog signals are present everywhere in the form of sound or sensor readings. But today’s digital systems, like microcontrollers and processors, can only work with binary numbers. For this we use analog-to-digital converters. Among the various ADC architectures, Successive Approximation Register (SAR) ADCs are widely preferred due to their low power consumption, small area, and moderate speed. However, existing SAR ADC designs still face major challenges such as high-power consumption, layout capacitor mismatch, and the requirement for stable reference voltages. These problems limit their accuracy, efficiency, and practical use in advanced applications. This Paper resolve these issues by designing four key blocks of a SAR ADC: a sample-and-hold circuit, comparator, SAR logic, and reference DAC. This Paper goal was to make the layout smaller and reduce power usage, while still ensuring accurate conversion.