Abstract: An FSK transceiver circuit, including a controlled oscillator used, in a transmission mode, to modulate a carrier by frequency shifts according to a binary transmission signal present on an input pin of the circuit, the shift amplitude being determined by an adjusting element connected to an adjusting pin of the circuit; two mixers connected to receive a reception signal present on a receive pin and, respectively, two carriers in phase quadrature of the controlled oscillator that, in receive mode, receives no modulating signal; and a demodulator connected to the outputs of the mixers via respective filters, the output of one of the filters being accessible from the outside by a circuit test pin.

Abstract: The invention relates to a radio device comprising a primary oscillator, a phase locked loop driven by a signal provided by the primary oscillator and a radio emitter and/or receiver circuit receiving as an input a radio frequency signal provided by the phase locked loop. According to the invention, the device comprises means for powering-on the elements of the radio device in a progressive and sequential way, according to a determined starting order of these elements. Application in particular to sensors and meters with data teletransmission, to remote controlled actuators and radio-telephones.