LOW POWER, HIGH SPEED CURRENT CONVEYOR BASED CURRENT COMPARATOR IN PIPELINED ADC

Abstract

A current mode technique for the design of flash ADCs is presented. The current mode technique allows the necessary voltage swing for a given dynamic range to be reduced while at the same time eliminating the need of large capacitors on which to store charge. This thesis presents a flash ADC (Analog to Digital Converter) modules comprising of Current Mirror Circuits, Comparator Circuits and Encoder Circuit. A CCII network and positive feedback properties based novel approach of designing Current Comparator Circuit has been employed, which gives reduction in response time and hence increases the bandwidth. This makes the structure suitable for wide band applications. The presented ADC’s comparator structure uses the thermometer code for conversion of analog signal to digital one. The circuit has been simulated using the PSPICE simulator for 180nm CMOS technology with 1.8V supply to get satisfactory output.