US 2026/0213757 A1 · METHOD FOR STARTING UP A PHASE-LOCKED LOOP, AND CORRESPONDING INTEGRATED CIRCUIT

Abstract

In a start-up sequence of a phase-locked loop, the voltage-controlled oscillator is controlled by a first voltage to operate in a linear regime and a first count of a register of a frequency divider is read. Then, the voltage-controlled oscillator is controlled by a second voltage having an offset from the first voltage and a second count of the register is read. A slope of the linear regime is then determined from a difference between the first and second counts and an offset of the first and second voltages. A determination is made of a third voltage needed to reach a target frequency of the output signal as a function of the slope and a deviation between a current value of the register count and a target value corresponding to the target frequency. The voltage-controlled oscillator is then controlled with the third voltage.

Claims16

Dependent claims

A method for managing operation of a phase-locked loop which includes a voltage-controlled oscillator generating an output signal and a frequency divider configured to count pulses of the output signal in a register, the method comprising a start-up sequence including:

controlling the voltage-controlled oscillator with a first voltage that puts the voltage-controlled oscillator directly in a linear regime;
then reading a first count of the register;
controlling the voltage-controlled oscillator with a second voltage having an offset with respect to the first voltage;
then reading a second count of the register;
measuring a slope of the linear regime using a difference between the first count and the second count and an offset between the first voltage and the second voltage;
determining a third voltage needed to reach a target frequency of the output signal as a function of the slope and a deviation between a current value of the register count and a target value corresponding to the target frequency;
and
controlling the voltage-controlled oscillator with the third voltage.

5 more elements

An integrated circuit, comprising:

a phase-locked loop including a voltage-controlled oscillator generating an output signal and a frequency divider configured to count pulses of the output signal in a register;
and
a digital control circuit configured, during a start-up sequence, to:
control the voltage-controlled oscillator with a first voltage configured to put the voltage-controlled oscillator directly in a linear regime;
then read a first count of the register;
control the voltage-controlled oscillator with a second voltage having an offset with respect to the first voltage;
then read a second count of the register;
measure a slope of the linear regime using a difference between the first count and the second count and an offset between the first voltage and the second voltage;
determine a third voltage needed to reach a target frequency of the output signal as a function of the slope and a deviation between a current value of the register count and a target value corresponding to the target frequency;
and
control the voltage-controlled oscillator with the third voltage.

8 more elements

Dependencies are inferred from the claim text.

Method for starting up a phase-locked loop, and corresponding integrated circuit

Life of this patent

Method for starting up a phase-locked loop, and corresponding integrated circuit

Life of this patent

Abstract

Claims16