US 12,549,159 B2Granted

Injection locked phase rotator

AssigneeXilinx, Inc.

InventorsLi Yang Chen, Chi Fung Poon, Chuenhuei Chou

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Abstract

An injection locked ring oscillator (ILRO) system is disclosed. The ILRO system includes an ILRO circuit configured to receive a plurality of injection control signals and a phase control signal, and to generate a plurality of output clock signals; a phase detector circuit configured to receive the output clock signals and to generate a phase output signal based on phase differences of particular pairs of the output clock signals; and a phase to voltage circuit configured to receive the phase output signal from the phase detector circuit, and to generate the phase control signal based on the phase output signal, where the phase control signal presents a negative feedback phase signal to the ILRO circuit for the phase differences in the particular pairs of the output clock signals.

Claims20

Dependent claims

An injection locked ring oscillator (ILRO) system, comprising:

an ILRO circuit configured to receive a plurality of injection control signals and a phase control signal, and to generate a plurality of output clock signals;
a phase detector circuit configured to receive the output clock signals and to generate a phase output signal based on phase differences of particular pairs of the output clock signals, wherein each of the particular pairs consists of output clock signals having adjacent phases, wherein the phase detector circuit is configured such that:
phase differences between alternating pairs of the adjacent-phase output clock signals cause the phase control signal to adjust a delay in a first direction, and
phase differences between the remaining pairs of the adjacent-phase output clock signals cause the phase control signal to adjust the delay in a second direction opposite to the first direction;
and
a phase to voltage circuit configured to receive the phase output signal from the phase detector circuit, and to generate the phase control signal based on the phase output signal, wherein the phase control signal presents a negative feedback phase signal to the ILRO circuit for the phase differences in the particular pairs of the output clock signals.

3 more elements

An injection locked phase rotator (ILPR) circuit, comprising:

an ILPR decoder circuit configured to generate a plurality of injection control signals;
an injection locked ring oscillator (ILRO) circuit configured to receive the injection control signals and a phase control signal, and configured to generate a plurality of output clock signals;
a phase detector circuit configured to receive the output clock signals and to generate a phase output signal based on phase differences of particular pairs of the output clock signals separated by 45 degrees or less, wherein the particular pairs consist of phase-adjacent output clock signals, wherein the phase detector circuit maintains a constant polarity of the phase output signal while the injection control signals from the ILPR decoder circuit rotate through different phase positions;
and
a phase to voltage circuit configured to receive the phase output signal, and to generate the phase control signal based on the phase output signal.

2 more elements

A method of operating an injection locked phase rotator (ILPR) circuit, the method comprising:

with an ILPR decoder circuit, generating a plurality of injection control signals;
with an injection locked ring oscillator (ILRO) circuit, receiving the injection control signals from the ILPR decoder circuit;
with the ILRO circuit, receiving injection clocks;
with the ILRO circuit, receiving a phase control signal;
with the ILRO circuit, generating a plurality of output clock signals based on the injection control signals, the injection clocks, and the phase control signal;
with a phase detector circuit, receiving the output clock signals;
with the phase detector circuit, generating a phase output signal based on phase differences of particular pairs of the output clock signals, wherein the particular pairs of the output clock signals are separated by 45 degrees or less, and wherein the particular pairs consist of phase-adjacent output clock signals,
wherein generating the phase output signal comprises:
causing the phase control signal to adjust delay in a first direction based on phase differences between alternating pairs of the adjacent-phase output clock signals;
and
causing the phase control signal to adjust delay in a second direction opposite to the first direction based on phase differences between the remaining pairs of the adjacent-phase output clock signals;
with a phase to voltage circuit, receiving the phase output signal from the phase detector circuit;
and
with the phase to voltage circuit, generating the phase control signal based on the phase output signal.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/440,450Filed 13 Feb 2024
Published: US 2025/0260393 A114 Aug 2025
Granted: 10 Feb 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H03K 3/0322
Ring oscillators: with differential cells
H03B 27/00
Generation of oscillations providing a plurality of outputs of the same frequency
H03K 3/354
By the use, as active elements, of field-effect transistors with internal or external positive feedback: astable circuits
H03L 7/0995
Concerning mainly the controlled oscillator of the loop: the oscillator comprising a ring oscillator