Frequency adjustment circuit and method for voltage controlled oscillator with temperature compensation function

By combining the frequency calibration branch, the control voltage generation branch, and the phase-locked loop branch, the problem of phase-locked loop loss caused by the frequency change of the voltage-controlled oscillator with temperature was solved, and stable frequency compensation and noise reduction were achieved.

CN115833748BActive Publication Date: 2026-06-19SHANGHAI CHIPANALOG MICROELECTRONICS LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
SHANGHAI CHIPANALOG MICROELECTRONICS LTD
Filing Date
2022-12-23
Publication Date
2026-06-19

AI Technical Summary

⚠Technical Problem

The frequency of a voltage-controlled oscillator changes with temperature, causing the phase-locked loop to lose lock. In existing technologies, temperature compensation circuits introduce noise, which degrades phase noise performance.

⚗Method used

The system employs a frequency calibration branch, a control voltage generation branch, a temperature sensor, and a phase-locked loop branch. Temperature data is collected by the temperature sensor, and the control voltage is adjusted to lock the operating frequency of the voltage-controlled oscillator. This avoids the need for a PTAT voltage generation circuit and a varactor diode, thus reducing phase noise.

🎯Benefits of technology

Temperature compensation for the voltage-controlled oscillator frequency was achieved, which prevented phase noise degradation, ensured frequency stability, reduced phase noise, and achieved frequency locking.

✦ Generated by Eureka AI based on patent content.

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Abstract

The frequency adjustment circuit and method for a voltage-controlled oscillator (VCO) with temperature compensation function according to this application embodiment first generates a voltage signal through a control voltage generation branch and transmits it to the second signal control terminal of the VCO. The output signal of the VCO is divided by a phase-locked loop (PLL) branch and input to the frequency calibration branch along with a reference clock. A temperature sensor collects temperature data from the chip and sends the temperature data to the frequency calibration branch. The frequency calibration branch outputs a control signal to the first control signal terminal of the VCO based on the divided clock of the VCO's output signal, the reference clock, and the temperature data, so that the operating frequency of the VCO is the target frequency. The PLL branch locks the VCO operating at the target frequency. This solution avoids the PTAT voltage generation circuit and corresponding varactor diodes involved in traditional temperature compensation circuits, reduces phase noise, effectively achieves temperature compensation adjustment of the VCO, and realizes frequency locking.
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