US 12,368,441 B2 · Power supply calibration for voltage controlled oscillators

Abstract

A clock generation circuit has a voltage-controlled oscillator that includes a first transistor pair coupled in series between a power rail and ground, a replica transistor pair coupled in series between a reference node and ground, a current source having an output coupled to the reference node. The current source is coupled to a control signal that determines amplitude of current flowing through the replica transistor pair. A voltage regulator has an input coupled to the reference node and an output coupled to the power rail. The voltage regulator is configured to maintain the power rail at a voltage level defined by the voltage level of the reference node. Each transistor in the replica transistor pair is collocated on an integrated circuit with and has a same type as a corresponding transistor in the first transistor pair.

Claims27

Dependent claims

A clock generation circuit, comprising:

a voltage-controlled oscillator (VCO) comprising a first transistor pair coupled in series between a power rail and ground;
a replica transistor pair coupled in series between a reference node and ground and collocated on an integrated circuit with the first transistor pair, each transistor in the replica transistor pair being of a same type as a corresponding transistor in the first transistor pair;
a current source having an output coupled to the reference node;
a voltage regulator that has an input coupled to the reference node and that has an output coupled to the power rail, the voltage regulator being configured to maintain the power rail at a voltage level defined by the voltage level of the reference node;
a comparator having a first input coupled to a voltage reference signal and a second input coupled to the reference node;
and
a calibration circuit having an input coupled to an output of the comparator and configured to control the current source.

4 more elements

A method for generating clock signals, comprising:

configuring amplitude of a current provided by a current source to a replica transistor pair through a reference node;
and
providing power to a power rail of a voltage-controlled oscillator (VCO) using a voltage regulator that has an input coupled to the reference node, the voltage regulator being configured to maintain the power rail at a voltage level defined by the voltage level of the reference node,
wherein the VCO comprises a first transistor pair coupled in series between the power rail and ground,
wherein the replica transistor pair is coupled in series between the reference node and ground and is collocated on an integrated circuit with the first transistor pair,
wherein each transistor in the replica transistor pair is of a same type as a corresponding transistor in the first transistor pair;
comparing a voltage reference signal with voltage level of the reference node;
and
configuring the amplitude of the current provided by the current source using a result of comparing the voltage reference signal with the voltage level of the reference node.

6 more elements

An apparatus, comprising:

means for providing a current to a replica transistor pair, including a current source that is coupled to the replica transistor pair at a reference node;
means for configuring amplitude of the current provided to the replica transistor pair;
and
means for providing power to a power rail of a voltage-controlled oscillator (VCO), including a voltage regulator that has an input coupled to the reference node, the voltage regulator being configured to maintain the power rail at a voltage level defined by the voltage level of the reference node,
wherein the VCO comprises a first transistor pair coupled in series between the power rail and ground,
wherein the replica transistor pair includes transistors coupled in series between the reference node and ground, wherein the replica transistor pair is collocated on an integrated circuit with the first transistor pair,
wherein each transistor in the replica transistor pair is of a same type as a corresponding transistor in the first transistor pair, and
wherein the means for configuring the amplitude of the current is configured to
calibrate the current source using a comparator to compare a voltage reference signal with voltage level of the reference node;
and
configure the amplitude of the current based on a result of comparing the voltage reference signal with the voltage level of the reference node.

8 more elements

Dependencies are inferred from the claim text.

Power supply calibration for voltage controlled oscillators

Life of this patent

Power supply calibration for voltage controlled oscillators

Life of this patent

Abstract

Claims27