Control circuit and method for regulating the supply voltage of an SLIC circuit (15), having a monitoring circuit (36) for calculating an SLIC supply voltage which is required to reach a nominal supply current (I.sub.nom) for an analogue terminal (2) which is connected to the SLIC circuit (15); and having a DC/DC converter (53), which is controlled by the monitoring circuit (36), for converting a battery voltage (V.sub.batt) to the calculated SLIC supply voltage.