An integrated circuit (30) for non-contact operation by means of at least one coil (L) forming a tuned resonant circuit with a tuning capacitor (C.sub.A), including a charge pump (10) with two clock inputs (E.sub.1 E.sub.2), wherein the clock inputs (E.sub.1 E.sub.2) of the charge pump (10) are constantly connected to the terminals of the coil (L), at least during the periods of non-contact operation of the integrated circuit, whereby the charge pump, seen from the clock inputs thereof, is a constant component of the tuning capacitor of the tuned resonant circuit.