Abstract: Generally real time signals are analog in nature. For any type of applications such as in signal processing we require digital signals for processing so to convert the analog signals into digital “Analog to digital converter” is used. Nowadays for reducing chip size area designers searching analog to digital converter architectures using CMOS techniques. The performance of any digital system is depends on the performance parameter of analog to digital converter. In the basic ADC structure, resistors are used for generating the reference voltages at the comparator. So here we will design three resistorless circuits which reduces the power demand of an Analog to Digital Converter are 1) Switched Inverter Scheme (SIS) ADC 2) Clocked Switched Inverter Scheme ADC 3) Sleep transistor switched inverter scheme ADC. This paper presents design and resistorless Analog to Digital Converter with different comparators using CMOS transistors only. It improves efficiency, reduces chip area and also will operating on low power. Finally analysis of Analog to Digital Converters with different comparators will be made to achieve best efficient of Analog to Digital Converter among others.

Keywords: Analog to digital converter, low power, resistorless, switched inverter scheme (SIS) Comparator.