This paper explores a novel Built-in-Current Sensor (BICS) topology that handles both current detection and Delta-Sigma conversion to digital domain. This circuit is a compact solution that requires no extra block and operates transparently on the power supply. The proposed topology is flexible enough to address classic applications of failure testing (IDD-Quiescent) as well as accurate/fast control (IDD-transient) when needed. Its application in RF transceivers is considered.