US 2002/0118073 A1 · Phase and frequency-locked loop circuits

Abstract

The invention relates to phase and frequency-locked loop circuits (PLL and FLL circuits) with a controllable tracking oscillator whose signal phase relationship or frequency, respectively, is influenced by an external parameter, a reference oscillator, as well as a phase or frequency comparator, the output signal of which is used to control the tracking oscillator in such a way that any phase or frequency errors are reduced. The invention provides for an element for the measurement of the external parameter (such as a microprocessor) which is capable of receiving a signal representing the output signal of the phase or frequency comparator, and convert it into a measurement value that represents the present value of the external parameter. This external parameter can, for example, represent the ambient temperature or the supply voltage of the tracking oscillator.

Claims13

Dependent claims

A phase locked loop (PLL) circuit comprising:

a controllable tracking oscillator having a signal phase relationship dependent on an external parameter;
reference oscillator having a constant phase relationship;
a phase comparator to compare the phase relationship of the signal supplied from said controllable tracking oscillator with the phase relationship of the signal supplied by the reference oscillator and outputs an output signal corresponding to the phase shift to the tracking oscillator to reduce phase error;
an circuit for monitoring the external parameter to receive a signal to represent a characteristic of the output signal of the phase shift;
and
convert a signal to a measured valued which represents the real value of the external parameter.

3 more elements

Dependencies are inferred from the claim text.

Phase and frequency-locked loop circuits

Life of this patent

Phase and frequency-locked loop circuits

Life of this patent

Abstract

Claims13