Abstract: An apparatus suitable for use in identifying a noise component originating from a certain source of noise in a DSP-based mixed-signal system is provided. The apparatus includes a processing unit which receives a first signal released by a first signal path, the first signal path including a digital-to-analog converter and a first analog-to-digital converter. The processing unit also receives a second signal released by a second signal path, the second signal path including the digital-to-analog converter and a second analog-to-digital converter. The first signal and the second signal are processed to derive a noise component associated to a certain source of noise, the certain source of noise being a selected one of the digital-to-analog converter, the first analog-to-digital converter and the second analog-to-digital converter. A signal indicative of the noise component associated to the certain source of noise is then released.