Injection-controlled-locked phase-locked loop

• US 8,841,948 B1
• Filed: 03/14/2013
• Issued: 09/23/2014
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Original Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Inventors: Fang, Wayne, Upadhyaya, Parag, Savoj, Jafar, Chang, Kun-Yung, Chien, Jun-Chau
• Primary Examiner(s): HOUSTON, ADAM D
• Application Number:
  US13/830,729
• Time in Patent Office: 558 Days
• Field of Search: 327/149, 327/158
• US Class Current: 327/158
• CPC Class Codes: H03L 7/081 provided with an additional controlled phase shifter H03L7/0998 takes precedence
• CPC Class Codes: H03L 7/087 using at least two phase detectors or a frequency and phase detector in the loop
• CPC Class Codes: H03L 7/0995 the oscillator comprising a ring oscillator
• CPC Class Codes: H03L 7/24 using a reference signal directly applied to the generator

Abstract

An apparatus relates generally to an injection-controlled-locked phase-locked loop (“ICL-PLL”) is disclosed. In this apparatus, a delay-locked loop is coupled to an injection-locked phase-locked loop. An injection-locked oscillator of the injection-locked phase-locked loop is in a feedback loop path of the delay-locked loop.

Claims

1. An apparatus, comprising:

an injection-locked phase-locked loop; and

a delay-locked loop coupled to the injection-locked phase-locked loop;

wherein an injection-locked oscillator of the injection-locked phase-locked loop is in a feedback loop path of the delay-locked loop.

2. The apparatus according to claim 1, wherein the injection-locked phase-locked loop comprises an injection-locked ring phase-locked loop.

3. The apparatus according to claim 1, wherein the injection-locked phase-locked loop comprises a sub-harmonic injection-locked phase-locked loop.

4. The apparatus according to claim 1, wherein the delay-locked loop is coupled to self-calibrate pulse position of an injection pulse input of the injection-locked oscillator.

5. The apparatus according to claim 1, wherein the delay-locked loop is coupled to shape oscillator noise of the injection-locked oscillator.

6. The apparatus according to claim 1, wherein the delay-locked loop is coupled to shape oscillator noise of the injection-locked oscillator and to control pulse position of an injection pulse input of the injection-locked oscillator.

7. The apparatus according to claim 6, wherein the delay-locked loop is coupled to shape oscillator noise of the injection-locked oscillator with wideband second-order high-pass filtering responsive to position modulation of the injection pulse input of the injection-locked oscillator.

8. The apparatus according to claim 6, wherein the delay-locked loop is coupled to self-calibrate pulse position of the injection pulse input of the injection-locked oscillator.

9. An apparatus, comprising:

a pulse generator to receive a reference frequency signal to generate a pulse signal;

an adjustable delay to receive the pulse signal to provide a first delayed pulse signal;

an injection-locked oscillator coupled to receive the first delayed pulse signal and to receive a first control signal to provide an oscillator output signal responsive thereto;

wherein the first control signal is of a first locked loop;

wherein the first locked loop includes the injection-locked oscillator;

a second locked loop coupled to receive a reference signal and the oscillator output signal to provide a second control signal;

wherein the reference signal is either the reference frequency signal or a version of the pulse signal;

wherein the second locked loop includes the adjustable delay;

wherein the injection-locked oscillator is in a feedback path of the second locked loop; and

wherein the second control signal is coupled to control delay of the adjustable delay to control position of a pulse of the first delayed pulse signal for injection into the injection-locked oscillator.

10. The apparatus according to claim 9, wherein the second locked loop comprises a delay-locked loop.

11. The apparatus according to claim 10, wherein the first locked loop comprises an injection-locked phase-locked loop.

12. The apparatus according to claim 11, wherein:

the injection-locked oscillator comprises an injection-locked voltage controlled oscillator;

the first control signal is a first control voltage signal used to control the injection-locked voltage controlled oscillator;

the adjustable delay comprises a first voltage controlled delay line; and

the second control signal is a second control voltage signal used to control the injection-locked voltage controlled oscillator.

13. The apparatus according to claim 12, wherein:

the reference frequency signal and an inherent frequency of the injection-locked voltage controlled oscillator have a static phase offset; and

the reference frequency signal has a clock pattern.

14. The apparatus according to claim 12, wherein:

a frequency-locked loop of the injection-locked phase-locked loop is coupled to receive the reference frequency signal and the oscillator output signal to provide a voltage output; and

a voltage regulator of the injection-locked phase-locked loop is coupled to receive the voltage output to provide the first control voltage signal.

15. The apparatus according to claim 12, further comprising:

a second voltage controlled delay line of the delay-locked loop coupled to receive the reference signal to provide a second delayed pulse signal;

a phase detector of the delay-locked loop coupled to receive the oscillator output signal and the second delayed pulse signal for feedback;

wherein the phase detector is configured to provide an output voltage signal responsive to a detected phase difference between the oscillator output signal and the second delayed pulse signal; and

converter circuitry of the delay-locked loop coupled to receive the output voltage signal to provide the second control voltage signal.

16. The apparatus according to claim 15, wherein the phase detector comprises a sub-sampling phase detector.

17. The apparatus according to claim 15, wherein the converter circuitry comprises:

a voltage-to-current converter coupled to receive the output voltage signal to provide a current signal;

a capacitor coupled to receive the current signal and to a ground;

wherein the capacitor is coupled to charge or discharge responsive to the current signal to provide the second voltage control signal; and

wherein the first voltage controlled delay line is coupled to receive the second voltage control signal to control delay of the pulse signal for providing the first delayed pulse signal.

18. The apparatus according to claim 17, wherein:

the converter circuitry includes a calibration circuit;

the calibration circuit is configured to determine whether the second control voltage signal is above a threshold voltage level; and

the calibration circuit is configured to reset the injection-locked phase-locked loop responsive to the second control voltage signal not being above the threshold voltage level.

19. A method, comprising:

obtaining a reference frequency signal by an injection-locked phase-locked loop;

generating a pulse signal with a pulse generator of the injection-locked phase-locked loop coupled to receive the reference frequency signal;

providing a reference signal to a delay-locked loop coupled to the injection-locked phase-locked loop;

wherein the reference signal is either the pulse signal or the reference frequency signal;

self-adjusting a delay of the delay-locked loop to control pulse injection in the injection-locked phase-locked loop responsive to a detected phase difference between an injection-locked oscillator output of the injection-locked phase-locked loop and a version of the reference signal; and

outputting the injection-locked oscillator output from the injection-locked phase-locked loop.

20. The method according to claim 19, wherein the self-adjusting of the delay of the delay-locked loop comprises:

generating a first delay and a second delay to respectively provide a first version of the pulse signal and a second version of the pulse signal;

wherein the first version of the pulse signal is the version of the reference signal;

inputting the first version of the pulse signal and the injection-locked oscillator output to a phase detector of the delay-locked loop;

converting a detected phase difference between the first version of the pulse signal and the injection-locked oscillator output to a control signal;

adjusting the second delay responsive to the control signal;

wherein the second delay of the second version of the pulse signal is controlled to control the pulse injection responsive to the control signal; and

inputting the second version of the pulse signal to an injection-locked oscillator of the injection-locked phase-locked loop for the pulse injection to control phase locking of the injection-locked phase-locked loop.