The book is based on masters thesis of the author. The author has very effectively carried out the design and simulations of the flash ADC circuits with 3 bits, 4 bits, 6 bits and 8 bits. The simulations are carried out using T-SPICE. The importance of the impact of an improvement in the basic ADC architecture, the flash ADC is emphasized by showing us the possibility and need of the hour to encourage the use of the CMOS inverter based ADCs in SoC applications.