Phase-locked loop device with managed transition to random noise operation mode, comprising at least: - a bang-bang non-linear phase comparator with a first comparator input intended for receiving a reference signal having a reference frequency, a second comparator input for receiving a frequency-converted signal, and a comparator output (1 c) adapted for producing an error signal comprised of one out of two discrete values at each time; - a loop filter of proportional-integral type, with a filter input connected to the comparator output, at least one configuration input (2b, 2c) for receiving respective values of a proportional coefficient (K P) and integral coefficient (K I), and suitable for producing at a filter output a time-filtered error signal in accordance with the values received for said proportional and integral coefficients; - a voltage-controlled oscillator module, having at least one control input for receiving a control signal, and a VCO output for producing a VCO signal having a VCO frequency varying as a function of the control signal; - at least one control connection arranged for connecting the filter output to the control input of the VCO module, so that the control signal is based on the time-filtered error signal; - a frequency converter, connected at input to the VCO output, and adapted for producing at a converter output the frequency-converted signal based on the VCO signal, said converter ouput being connected to the second comparator input (1 b); and - a lock detector, arranged for producing a lock signal indicating whether a lock condition is met during a current operation of the PLL device, and an oscillation-length value indicating a duration between two successive sign reversals for a phase time-shift currently existing for the frequency-converted signal relative to the reference signal; characterized in that the PLL device further comprises a loop controller connected at an input of said loop controller for receiving the lock signal and the oscillation-length value, and connected at an output of said controller to the at least one configuration input (2b, 2c) of the loop filter, and adapted for selecting and producing at output the values of the proportional (K P) and integral (K I) coefficients based on the following tests which are continually executed during the operation of the PLL device: /i/ if the lock condition is met, then replacing the respective values of the proportional (K P) and integral (K I) coefficients as currently used within the loop filter, with new values selected respectively for said proportional and integral coefficients, each of said new values being smaller than the corresponding value currently used; and /ii/ if the lock condition is not met and the duration between two successive sign reversals for the phase time-shift is longer than a first duration threshold, then replacing the respective values of the proportional (K P) and integral (K I) coefficients as currently used within the loop filter, with former values which were used respectively for said proportional and integral coefficients before the values currently used have been selected. - a bang-bang non-linear phase comparator with a first comparator input intended for receiving a reference signal having a reference frequency, a second comparator input for receiving a frequency-converted signal, and a comparator output (1 c) adapted for producing an error signal comprised of one out of two discrete values at each time; - a loop filter of proportional-integral type, with a filter input connected to the comparator output, at least one configuration input (2b, 2c) for receiving respective values of a proportional coefficient (K P) and integral coefficient (K I), and suitable for producing at a filter output a time-filtered error signal in accordance with the values received for said proportional and integral coefficients; - a voltage-controlled oscillator module, having at least one control input for receiving a control signal, and a VCO output for producing a VCO signal having a VCO frequency varying as a function of the control signal; - at least one control connection arranged for connecting the filter output to the control input of the VCO module, so that the control signal is based on the time-filtered error signal; - a frequency converter, connected at input to the VCO output, and adapted for producing at a converter output the frequency-converted signal based on the VCO signal, said converter ouput being connected to the second comparator input (1 b); and - a lock detector, arranged for producing a lock signal indicating whether a lock condition is met during a current operation of the PLL device, and an oscillation-length value indicating a duration between two successive sign reversals for a phase time-shift currently existing for the frequency-converted signal relative to the reference signal; /i/ if the lock condition is met, then replacing the respective values of the proportional (K P) and integral (K I) coefficients as currently used within the loop filter, with new values selected respectively for said proportional and integral coefficients, each of said new values being smaller than the corresponding value currently used; and /ii/ if the lock condition is not met and the duration between two successive sign reversals for the phase time-shift is longer than a first duration threshold, then replacing the respective values of the proportional (K P) and integral (K I) coefficients as currently used within the loop filter, with former values which were used respectively for said proportional and integral coefficients before the values currently used have been selected.