current generator provides a current varying as a function of a voltage and inversely proportional to a resistor value in a first step the phase loop causes the oscillator to oscillate at a frequency f0 and the resistor has a value r0 in a second phase the loop is opened and the resistor is given a value r1 causing the oscillator to oscillate at a frequency f1 f0 u00d7 r0 r1 application_number US 18425888 A description the block diagram of fig1 shows the main components of the frequency generator according to the invention a current generator gc controlled by a voltage and the output current of which is proportional to a resistor value the oscillator ico the phase comparator phc the current generator gc and the capacitor c constitute a phase loop through which the output frequency f of the generator is adjusted on a reference frequency f0 provided to the phase comparator phc the reference frequency is obtained either externally from the integrated circuit implementing the invention or within the same integrated circuit in the example the reference frequency f0 is provided by an oscillator gfr inside the integrated circuit associated with an external quartz crystal the phase comparator receives the reference frequency signal f0 and the output signal from the oscillator ico and provides an output current representing the phase shift between the frequencies of the signals the current is applied through switch k to the capacitor c used for smoothing the current variations and used in the example for storing the output voltage generated.