Frequency synthesizers with adjustable delays

摘要

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.

主权项

1. A frequency synthesizer system for producing a radio frequency (RF) signal with an RF frequency that is responsive to a frequency reference (FREF) clock, the system comprising:
an inductive-capacitive (LC) tank oscillator circuit configured to generate the RF signal; a digital to time converter (DTC) circuit configured to operate, for a first edge of the FREF clock, in a baseline mode that introduces a first delay value to the FREF clock, 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 configured to enable the LC-tank oscillator circuit in response to a first edge of the FREF clock and to set the second delay value as a function of the frequency of the RF signal; and a phase detector circuit configured to detect, for the subsequent edges of the FREF clock and with the delay of the DTC circuit, a phase difference between the FREF clock and the RF signal.