A device for testing an analog-to-digital converter providing a digital signal at a given sampling frequency, comprising a unit for providing a test signal to the converter, the test signal being a periodic signal comprising frequency components only at a fundamental frequency and at harmonics of the fundamental frequency, the fundamental frequency being a multiple of one quarter of the sampling frequency; a filter capable of receiving the digital signal and of rejecting the fundamental frequency to provide a filtered digital signal; and a unit capable of receiving the digital signal and the filtered digital signal and of providing a signal representative of the ratio between the effective powers of the digital signal and of the filtered digital signal.