A radio frequency (RF) signal can be produced with an RF frequency that is responsive to a frequency reference (FREF) clock. An inductive-capacitive (LC) tank oscillator circuit can generate the RF signal. A digital to time converter (DTC) circuit can operate, for a first edge of the FREF clock, in a baseline mode that has a first delay, and for a subsequent edge of the FREF clock, in a delay mode that introduces a second delay value to the FREF clock. A controller circuit can enable the LC-tank oscillator circuit in response to a first edge of the FREF clock and to set or increase the second delay value of the delay mode as a function of the frequency of the RF signal. A phase detector circuit can detect, for the subsequent edge of the FREF clock, a phase difference between the FREF clock and the RF signal.