An active implantable medical device having an RF telemetry circuit. The device is in particular a stimulation, resynchronization, defibrillation and/or cardioversion device. It includes a principal circuit, an RF telemetry auxiliary circuit and a supply battery for the principal and auxiliary circuits. It is envisaged to have between the supply battery and the auxiliary circuit a regulating circuit including an accumulator of electric power coupled with the auxiliary circuit to deliver a current ready to feed the auxiliary circuit, and a load circuit coupled with the supply battery to maintain the accumulator on a predetermined level of load.