Optimisation of a Pipeline ADC by using a low power, high resolution Flash ADC as backend.

Abstract

Flash ADCs with resolutions from 3 to 5 bits have been implemented on a transistor level. These ADCs are to be incorporated as the backend of a higher resolution Pipeline ADC. The motivation for this work has been to see how much the resolution of this backend can be increased before the power consumption becomes to high. This is beneficial in Pipeline ADCs because the number of Pipeline stages is reduced so that the throughput delay of the Pipeline ADC is also reduced. All the Flash ADCs are implemented with the same Capacitive Interpolation-technique. This technique was found to have several benificial properties as opposed to other power saving techniques applied to Flash ADCs in a project assignment done prior to this thesis. The results of the simulations show that the resolution of the backend can be increased to 5 bits both in terms of power and other static and dynamic performance parameters.