Today’s telecommunications are essentially digital because of its advantages in term of speed, versatility and robustness. To implement a digital communication channel is fundamental the use of analog to digital and digital to analog converters. The main goal is to have higher bandwidths necessary, for instance, to have faster computer networks or new services in mobile phones, like video or broadband internet. To achieve this, analog to digital converters (ADCs) are constantly being improved and their capacity pushed to the limit. One factor that affects ADC performance is the presence of phase noise in the analog signals being converted, due, for instance, to the use of higher frequency local oscillators, and the presence of jitter in the sampling of the analog signal required to convert it to digital. Both of theses phenomena, which generally can be studied together, affect the behavior of the ADC. In this project we propose to study the influence of phase noise and jitter in the results of ADC testing. It’s influence on those results depends on the test method chosen. Two of the methods we propose to study are the Histogram Method and the DFT Method. The first one is used to determine the ADC transfer function, integral non linearity (INL), differential nonlinearity (DNL), gain error and offset error. The second one, the DFT Method, is used to determine ADC signal to noise and distortion ratio (SINAD), total harmonic distortion (THD), noise and effective number of bits (ENOB).