This paper describes the process variation and it effect on ADC considering the all corners of the CMOS technology, explains how the process variation at every corner at deep submicron nodes and one of the electrical parameter of device components changes at device process corners. A brief working principle about Analog to digital circuits is given, as well as a explanation of process variations. This specific circuit design carried out using submicron foundry based process design kit. In a modern systems on chip transmitter and receiver such as LTE and many blocks are fundamentally consists of data conversion, which essential part of the today’s semiconductor chip. The complex signal processing preformed is primarily comprised of digital signal processing which is discrete values for analysis rather than considering continuous values, which is also called quantization, data conversions to and from discrete to continuous and continuous to discrete (ADC/DAC) and discrete quantization and continuous signal domains.