US 7,924,099 B2 · Method of establishing an oscillator clock signal

Abstract

A hybrid numeric-analog clock synchronizer, for establishing a clock or carrier locked to a timing reference. The clock may include a framing component. The reference may have a low update rate. The synchronizer achieves high jitter rejection, low phase noise and wide frequency range. It can be integrated on chip. It may comprise a numeric time-locked loop (TLL) with an analog phase-locked loop (PLL). Moreover a high-performance number-controlled oscillator (NCO), for creating an event clock from a master clock according to a period control signal. It processes edge times rather than period values, allowing direct control of the spectrum and peak amplitude of the justification jitter. Moreover a combined clock-and-frame asynchrony detector, for measuring the phase or time offset between composite signals. It responds e.g. to event clocks and frame syncs, enabling frame locking with loop bandwidths greater than the frame rate.

Claims20

Dependent claims

A method of establishing an event clock comprising a stream of event-clock pulses, the method comprising the steps of:

establishing a representation of an idealized clock comprising a stream of target times on a basis of a stream of period control representations by a process that involves accumulation, values of said period control representations representing a desired period of said event clock with respect to that of a master clock,
establishing a stream of master-clock pointers by justifying said idealized clock to said master clock by a process that involves resolution reduction while performing spectrum control of associated justification jitter, thereby facilitating number-controlled oscillation with improved control of said justification jitter, and
establishing said stream of event-clock pulses on the basis of said stream of master-clock pointers and said master clock.

Dependencies are inferred from the claim text.

Method of establishing an oscillator clock signal

Life of this patent

Method of establishing an oscillator clock signal

Life of this patent

Abstract

Claims20