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CN-122026812-A - Oscillator calibration circuit, calibration method, oscillator and electronic device

CN122026812ACN 122026812 ACN122026812 ACN 122026812ACN-122026812-A

Abstract

The application relates to the technical field of integrated circuits and discloses an oscillator calibration circuit, a calibration method, an oscillator and electronic equipment, wherein the circuit comprises a voltage-controlled oscillator, a clock processing module, an error amplifying module, an open-loop control module and a calibration module, and the voltage-controlled oscillator generates a main clock signal; the clock processing module carries out frequency division processing on a main clock signal to generate a calibration starting signal and a conversion clock signal, the error amplifying module outputs an error voltage signal of which the detection port is amplified, the open-loop control module responds to the effective state of the calibration starting signal to enable the error amplifying module to enter an open-loop working mode, the calibration module responds to the conversion clock signal, adopts a successive approximation mode to start from a preset initial calibration code, applies bit-by-bit calibration excitation to the error amplifying module, detects the polarity change of the error voltage signal of the error amplifying module relative to an input short-circuit state, generates a target digital calibration code, and compensates the error amplifying module based on the target digital calibration code.

Inventors

  • CHEN SU

Assignees

  • 深圳市汇春科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260126

Claims (10)

  1. 1. An oscillator calibration circuit, comprising: A voltage controlled oscillator for generating a master clock signal; The clock processing module is connected with the output end of the voltage-controlled oscillator and is used for carrying out frequency division processing on the master clock signal to generate a calibration starting signal and a conversion clock signal; the error amplifying module is used for outputting an error voltage signal amplified by the detection port; The control end of the open-loop control module is used for receiving the calibration starting signal, and the open-loop control module responds to the effective state of the calibration starting signal to enable the error amplification module to enter an open-loop working mode; And the calibration module is electrically connected with the clock processing module and the error amplifying module respectively and is used for responding to the converted clock signal, applying a bit-by-bit calibration excitation to the error amplifying module from a preset initial calibration code in a successive approximation mode, detecting the polarity change of an error voltage signal of the error amplifying module relative to an input short circuit state, generating a target digital calibration code and compensating the error amplifying module based on the target digital calibration code.
  2. 2. The oscillator calibration circuit of claim 1, wherein the calibration module comprises a bitwise approximation logic unit; The successive approximation logic unit is used for responding to each effective edge of the conversion clock signal, and starting from the most significant bit of the preset initial calibration code, sequentially executing the following operations on each bit, namely setting the current bit to be judged to be high level, initializing the rest bits which are not judged to be low level, maintaining the current level of the judged bits to form a temporary calibration code and applying the temporary calibration code to the error amplification module, collecting the polarity of an error voltage signal of the error amplification module relative to an input short circuit state, confirming that the current bit to be judged is high level if the polarity indicates that the output voltage deviates towards a preset compensation direction, otherwise setting the current bit to be low level, and generating the target digital calibration code after all bits are judged to be finished in sequence.
  3. 3. The oscillator calibration circuit of claim 1, wherein, The open loop control module comprises a first control switch, a second control switch and a third control switch; The first control switch is arranged between the output end of the error amplifying module and the input end of the voltage-controlled oscillator in series, the second control switch is arranged between the non-inverting input end and the inverting input end of the error amplifying module in series, and the third control switch is electrically connected with the inverting input end of the error amplifying module.
  4. 4. The oscillator calibration circuit of claim 1, further comprising: and the energy storage module is electrically connected with the output end of the error amplification module.
  5. 5. The oscillator calibration circuit of claim 1, further comprising a drive module, the error amplification module being coupled to the voltage controlled oscillator through the drive module.
  6. 6. An oscillator calibration method, wherein the calibration method is applied to the oscillator calibration circuit according to any one of claims 1 to 5, and comprises: Responding to a conversion clock signal, applying a bitwise calibration excitation to an error amplification module from a preset initial calibration code in a successive approximation mode, detecting polarity change of an error voltage signal of the error amplification module relative to an input short circuit state, and generating a target digital calibration code; and compensating the error amplifying module based on the target digital calibration code.
  7. 7. The method of calibrating an oscillator according to claim 6, wherein, The response conversion clock signal adopts a successive approximation mode, starting from a preset initial calibration code, applying a bitwise calibration excitation to an error amplification module, detecting the polarity change of an error voltage signal of the error amplification module relative to an input short circuit state, and generating a target digital calibration code comprises: In response to each valid edge of the transition clock signal, starting from the most significant bit of the preset initial calibration code, performing the following operations on each bit in turn: setting the current bit to be judged as high level, initializing the rest bits which are not judged as low level, and maintaining the current level by the judged bits to form a temporary calibration code and applying the temporary calibration code to the error amplifying module; if the polarity indicates that the output voltage deviates towards the preset compensation direction, confirming that the current bit to be judged is at a high level, otherwise, setting the current bit to be judged as a low level; And after all bits are judged to be finished in sequence, generating the target digital calibration code.
  8. 8. The oscillator calibration method of claim 6, wherein the compensating the error amplification module based on the target digital calibration code comprises: comparing the currently generated target digital calibration code with the historical digital calibration code of the previous calibration period; If the target digital calibration code is larger than the historical digital calibration code, adding one to the target digital calibration code to be used as a current compensation value; if the target digital calibration code is smaller than the historical digital calibration code, subtracting one from the target digital calibration code to serve as the current compensation value; And writing the compensation value into the error amplifying module for compensation.
  9. 9. An oscillator, characterized in that the oscillator comprises an oscillator calibration circuit according to any one of claims 1 to 5.
  10. 10. An electronic device, characterized in that, the electronic device comprising the oscillator of claim 9.

Description

Oscillator calibration circuit, calibration method, oscillator and electronic device Technical Field The present application relates to the field of integrated circuits, and in particular, to an oscillator calibration circuit, an oscillator calibration method, and an electronic device. Background Along with the rapid development of integrated circuit technology, the importance of the oscillator circuit as a core time sequence unit of a digital system is increasingly highlighted, and the frequency precision and the stability of the oscillator circuit directly determine the overall performance of key electronic devices such as a processor, a communication chip and the like. The Voltage-controlled oscillator (VCO) implements a closed-Loop adjustment mechanism of an oscillation frequency through an error amplification module, and the architecture is widely applied to high-precision timing control systems such as Phase-Locked Loop (PLL), clock data recovery (Clock Data Recovery, CDR), and the like. In a conventional implementation, an error amplifier generates a control signal by precisely comparing the difference between a reference voltage and a feedback voltage, and the control signal is low-pass filtered to drive a voltage-controlled oscillator to output a target frequency signal. However, the error amplifier inevitably has a non-ideal parameter of the input offset voltage (Input Offset Voltage) due to the inherent characteristics of the semiconductor manufacturing process. The parameter is directly coupled to the control voltage signal, which causes a systematic shift in the actual control characteristic of the vco, and eventually deviates from a predetermined design specification. Disclosure of Invention In view of the above, embodiments of the present application provide an oscillator calibration circuit, a calibration method, an oscillator, and an electronic apparatus, which can effectively solve the technical problems of clock frequency offset and poor stability caused by input offset voltage of an error amplification module in the existing oscillator circuit. In a first aspect, an embodiment of the present application provides an oscillator calibration circuit, including: A voltage controlled oscillator for generating a master clock signal; The clock processing module is connected with the output end of the voltage-controlled oscillator and is used for carrying out frequency division processing on the master clock signal to generate a calibration starting signal and a conversion clock signal; the error amplifying module is used for outputting an error voltage signal amplified by the detection port; The control end of the open-loop control module is used for receiving the calibration starting signal, and the open-loop control module responds to the effective state of the calibration starting signal to enable the error amplification module to enter an open-loop working mode; And the calibration module is electrically connected with the clock processing module and the error amplifying module respectively and is used for responding to the converted clock signal, applying a bit-by-bit calibration excitation to the error amplifying module from a preset initial calibration code in a successive approximation mode, detecting the polarity change of an error voltage signal of the error amplifying module relative to an input short circuit state, generating a target digital calibration code and compensating the error amplifying module based on the target digital calibration code. In some embodiments, the calibration module includes a bitwise approximation logic unit; The successive approximation logic unit is used for responding to each effective edge of the conversion clock signal, and starting from the most significant bit of the preset initial calibration code, sequentially executing the following operations on each bit, namely setting the current bit to be judged to be high level, initializing the rest bits which are not judged to be low level, maintaining the current level of the judged bits to form a temporary calibration code and applying the temporary calibration code to the error amplification module, collecting the polarity of an error voltage signal of the error amplification module relative to an input short circuit state, confirming that the current bit to be judged is high level if the polarity indicates that the output voltage deviates towards a preset compensation direction, otherwise setting the current bit to be low level, and generating the target digital calibration code after all bits are judged to be finished in sequence. In some embodiments, the open loop control module includes a first control switch, a second control switch, and a third control switch; The first control switch is arranged between the output end of the error amplifying module and the input end of the voltage-controlled oscillator in series, the second control switch is arranged between the non-inverting input end and the inv