I. Introduction
In today’s generation electronic circuits, the main importance is given to high-speed and low power circuits to meet the needs of the applications. The flash ADC is such a device that has low power consumption [1]-[4] and high speed [5]-[6], and it is used to transform the analog form of data into digital form. The flash ADC contains mainly 3 blocks [7] they are resistive ladder, comparator, and encoder as shown in Fig. 1. The comparator, which the input is compared compares the with the threshold value from the resistor ladder network, is a crucial block that determines the performance of the flash ADC. 2N-1 comparators are required in a N-bit flash ADC. The resistive network [8] is used to provide the different threshold voltages for each comparator which is divided from the reference voltage. The comparator compares the analogue input signal to the threshold voltage, providing a 0 or 1 output depending on the inputs. The output of all the comparators is given to the encoder and its output is the representation of the analogue signal input in the digital form.