CN116318120B - Calibration circuit, calibration method, chip and electronic equipment of RC oscillation clock - Google Patents

Calibration circuit, calibration method, chip and electronic equipment of RC oscillation clock Download PDF

Info

Publication number
CN116318120B
CN116318120B CN202310361829.3A CN202310361829A CN116318120B CN 116318120 B CN116318120 B CN 116318120B CN 202310361829 A CN202310361829 A CN 202310361829A CN 116318120 B CN116318120 B CN 116318120B
Authority
CN
China
Prior art keywords
clock
calibration
frequency deviation
oscillation
fine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202310361829.3A
Other languages
Chinese (zh)
Other versions
CN116318120A (en
Inventor
元恒敏
张培卓
邱汉安
戴杰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guixin Technology Shenzhen Co ltd
Original Assignee
Guixin Technology Shenzhen Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guixin Technology Shenzhen Co ltd filed Critical Guixin Technology Shenzhen Co ltd
Priority to CN202310361829.3A priority Critical patent/CN116318120B/en
Publication of CN116318120A publication Critical patent/CN116318120A/en
Application granted granted Critical
Publication of CN116318120B publication Critical patent/CN116318120B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
    • H03L1/00—Stabilisation of generator output against variations of physical values, e.g. power supply
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Landscapes

  • Electric Clocks (AREA)
  • Oscillators With Electromechanical Resonators (AREA)

Abstract

The invention provides a calibration circuit, a calibration method, a chip and electronic equipment of an RC oscillation clock, comprising the following steps: the RC oscillator is used for outputting an RC oscillation clock, and a fine tuning capacitor array and a coarse tuning capacitor array are arranged in the RC oscillator; the reference clock module is used for outputting a reference clock; the first counting module is used for counting the periods of the reference clock by taking the periods of the RC oscillation clocks as a first time window; the first comparison module is used for comparing the actual count value of the reference clock with the base count value of the reference clock to obtain the frequency deviation of the RC oscillation clock; the calibration module is used for calculating a fine adjustment value according to the frequency deviation of the RC oscillation clock, and the RC oscillator is also used for adjusting the bit of the fine adjustment capacitor array according to the fine adjustment value so as to adjust the frequency of the RC oscillation clock. The invention can not only meet the calibration precision, but also save the power consumption to the maximum extent.

Description

Calibration circuit, calibration method, chip and electronic equipment of RC oscillation clock
Technical Field
The present invention relates to the field of integrated circuits, and in particular, to a calibration circuit, a calibration method, a chip and an electronic device for an RC oscillation clock.
Background
The mobile communication terminal generally has two clocks, a system clock and a sleep clock, and the system clock mainly provides a clock source for the whole system in a normal mode, so that the mobile communication terminal can work normally in a normal working mode. The sleep clock generally has two functions, namely, providing periodic wake-up for the mobile communication terminal when the system enters a sleep mode (DEEP SLEEP mode) so as to receive paging of the base station, and providing clock date and time for the system when the whole system enters an Ultra-low Power Sleep mode (UPS, also called PSM, power saving mode) or a shutdown mode (shutdown Down mode), and displaying running clock before startup in a timing mode.
In the prior art, the sleep clock can be provided by an RC oscillator, but because of the characteristics of the RC oscillator, the frequency offset of the RC oscillator is about +/-200 ppm at normal temperature, and the influence of factors such as chip difference, voltage, temperature and the like is added, a large frequency deviation is often generated after the RC oscillator is shut down for a period of time, so that the RC oscillator needs to be calibrated regularly. How to calibrate the RC oscillating clock with high accuracy is a great challenge for each designer.
Disclosure of Invention
In view of the above, the present invention provides a calibration circuit, a calibration method, a chip and an electronic device for an RC oscillation clock, which can calibrate the RC oscillation clock with high accuracy and can save power consumption to the maximum extent.
In a first aspect, the present invention provides a calibration circuit for an RC oscillating clock, comprising:
The RC oscillator is used for outputting an RC oscillation clock, and a fine adjustment capacitor array and a coarse adjustment capacitor array are arranged in the RC oscillator and are respectively used for carrying out fine adjustment and coarse adjustment on the capacitance value of the RC oscillator;
The reference clock module is used for outputting a reference clock;
The first counting module is used for receiving the RC oscillation clocks and the reference clocks, and counting the periods of the reference clocks by taking the periods of a plurality of the RC oscillation clocks as a first time window to obtain the actual count value of the reference clocks;
the first comparison module is used for comparing the actual count value of the reference clock with the reference count value of the reference clock in the first time window to obtain the frequency deviation of the RC oscillation clock;
The calibration module is used for calculating a fine adjustment value according to the frequency deviation of the RC oscillation clock when the frequency deviation of the RC oscillation clock is in the adjustable range of the fine adjustment capacitor array;
The RC oscillator is further used for adjusting the bit of the fine-tuning capacitor array according to the fine-tuning value so as to adjust the frequency of the RC oscillation clock.
In a second aspect, the present invention provides a calibration circuit for an RC oscillating clock, comprising:
The RC oscillator is used for outputting an RC oscillation clock, and a fine adjustment capacitor array and a coarse adjustment capacitor array are arranged in the RC oscillator and are respectively used for carrying out fine adjustment and coarse adjustment on the capacitance value of the RC oscillator;
The reference clock module is used for outputting a reference clock;
the second counting module is used for receiving the RC oscillation clock and the reference clock, counting the periods of the RC oscillation clock by taking a plurality of periods of the reference clock as a second time window, and obtaining an actual count value of the RC oscillation clock;
The second comparison module is used for comparing the actual count value of the RC oscillation clock with the reference count value of the RC oscillation clock in the second time window to obtain the frequency deviation of the RC oscillation clock;
The calibration module is used for calculating a fine adjustment value according to the frequency deviation of the RC oscillation clock when the frequency deviation of the RC oscillation clock is in the adjustable range of the fine adjustment capacitor array;
The RC oscillator is further used for adjusting the bit of the fine-tuning capacitor array according to the fine-tuning value so as to adjust the frequency of the RC oscillation clock.
Optionally, the RC oscillation clock is a sleep clock of 32.768 KHz.
Optionally, the calibration circuit further comprises:
The calibration time interval configuration module is used for configuring the time interval of two times of calibration, and specifically comprises the following steps: configuring the time interval of any two times of calibration as fixed time;
Or dynamically configuring the time intervals of the current calibration and the next calibration according to the frequency deviation of the current calibration, shortening the time intervals of the current calibration and the next calibration if the frequency deviation of the current calibration is larger than a set threshold value, and increasing the time intervals of the current calibration and the next calibration or keeping the time intervals unchanged if the frequency deviation of the current calibration is smaller than the set threshold value;
Or according to the frequency deviation of the current calibration, configuring the time intervals of the current calibration and the next calibration as the time interval corresponding to the gear where the frequency deviation is located.
Optionally, the calibration module is further configured to calculate a coarse adjustment value according to the frequency deviation of the RC oscillation clock when the frequency deviation of the RC oscillation clock exceeds the adjustable range of the fine adjustment capacitor array;
The RC oscillator is further used for adjusting the bit of the coarse adjustment capacitor array according to the coarse adjustment value, so that after coarse adjustment, the frequency deviation of the RC oscillation clock is within the adjustable range of the fine adjustment capacitor array.
In a third aspect, the present invention provides a method for calibrating an RC oscillation clock, including:
enabling a reference clock module when starting calibration, so that the reference clock module outputs a reference clock;
The first counting module receives the RC oscillation clocks and the reference clocks, and counts the periods of the reference clocks by taking the periods of a plurality of the RC oscillation clocks as a first time window to obtain actual count values of the reference clocks;
The first comparison module compares the actual count value of the reference clock with the reference count value of the reference clock in the first time window to obtain the frequency deviation of the RC oscillation clock;
when the frequency deviation of the RC oscillation clock is in the adjustable range of the fine-tuning capacitor array, the calibration module calculates to obtain a fine-tuning value according to the frequency deviation of the RC oscillation clock;
The RC oscillator adjusts the bit of the built-in fine-tuning capacitor array according to the fine tuning value so as to adjust the frequency of the RC oscillation clock;
and closing the reference clock module after the calibration is completed.
In a fourth aspect, the present invention provides a calibration method for an RC oscillation clock, including:
enabling a reference clock module when starting calibration, so that the reference clock module outputs a reference clock;
The second counting module receives the RC oscillation clock and the reference clock, and counts the periods of the RC oscillation clock by taking the periods of a plurality of the reference clocks as a second time window to obtain an actual count value of the RC oscillation clock;
The second comparison module compares the actual count value of the RC oscillation clock with the reference count value of the RC oscillation clock in the second time window to obtain the frequency deviation of the RC oscillation clock;
when the frequency deviation of the RC oscillation clock is in the adjustable range of the fine-tuning capacitor array, the calibration module calculates to obtain a fine-tuning value according to the frequency deviation of the RC oscillation clock;
The RC oscillator adjusts the bit of the fine-tuning capacitor array according to the fine-tuning value so as to adjust the frequency of the RC oscillation clock;
and closing the reference clock module after the calibration is completed.
Optionally, the RC oscillation clock is a sleep clock of 32.768 KHz.
Optionally, the time interval of any two calibrations is configured as a fixed time;
Or dynamically configuring the time interval of the current calibration and the next calibration according to the frequency deviation of the current calibration, if the frequency deviation of the current calibration is larger than a set threshold value, shortening the time interval of the current calibration and the next calibration, and if the frequency deviation of the current calibration is smaller than the set threshold value, increasing the time interval of the current calibration and the next calibration or keeping the time interval unchanged;
Or according to the frequency deviation of the current calibration, configuring the time intervals of the current calibration and the next calibration as the time interval corresponding to the gear where the frequency deviation is located.
Optionally, the calibration method further comprises:
When the frequency deviation of the RC oscillation clock exceeds the adjustable range of the fine-tuning capacitor array, the calibration module calculates a coarse tuning value according to the frequency deviation of the RC oscillation clock;
The RC oscillator adjusts the bit of the built-in coarse tuning capacitor array according to the coarse tuning value, so that after coarse tuning, the frequency deviation of the RC oscillation clock is within the adjustable range of the fine tuning capacitor array.
In a fifth aspect, the present invention provides a chip comprising a calibration circuit for an RC oscillating clock as described above.
In a sixth aspect, the present invention provides an electronic device, including the above chip.
According to the calibration circuit, the calibration method, the chip and the electronic equipment of the RC oscillation clock, the capacitor array arranged in the RC oscillator is directly adjusted according to the frequency deviation of the RC oscillation clock, so that the calibration of the RC oscillation clock is realized, the precision problem of the RC oscillation clock is solved from the source, the output precision of the RC oscillation clock is improved, and the accurate display time can be ensured when the RC oscillation clock is turned on again under ultra-low power consumption or long-term shutdown. And the reference clock is enabled during calibration, and the reference clock is closed after the calibration is completed, so that the power consumption can be saved to the greatest extent.
Drawings
FIG. 1 is a schematic diagram of a calibration circuit of an RC oscillation clock according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a calibration circuit of an RC oscillation clock according to an embodiment of the present invention;
FIG. 3 is a schematic diagram illustrating an internal circuit of an RC oscillator according to an embodiment of the present invention;
FIG. 4 is a flow chart illustrating a calibration method of an RC oscillation clock according to an embodiment of the present invention;
fig. 5 is a flowchart illustrating a calibration method of an RC oscillation clock according to an embodiment of the invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe the embodiments of the application herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Furthermore, the terms "mounted," "configured," "provided," "connected," "coupled," and "sleeved" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.
Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.
One embodiment of the present invention provides a calibration circuit for an RC oscillation clock, as shown in fig. 1, the calibration circuit comprising:
the RC oscillator 101 is configured to output an RC oscillation clock RCCLK, and a Fine (Fine Tune) capacitor array and a Coarse (Coarse Tune) capacitor array are disposed in the RC oscillator 101, and are respectively configured to perform Fine tuning and Coarse tuning on a capacitance value of the RC oscillator 101;
a reference clock module 102 for outputting a reference clock REFCLK;
a first counting module 103, configured to receive the RC oscillation clock RCCLK and the reference clock REFCLK, count the periods of the reference clock REFCLK with the periods of the plurality of RC oscillation clocks RCCLK as a first time window, and obtain an actual count value real_num1 of the reference clock;
A first comparing module 104, configured to compare the actual count value real_num1 of the reference clock with the reference count value ref_num1 of the reference clock to obtain a frequency deviation FE1 of the RC oscillation clock;
The calibration module 105 is configured to calculate a fine adjustment value according to the frequency deviation FE1 of the RC oscillation clock when the frequency deviation FE1 of the RC oscillation clock is within the adjustable range of the fine adjustment capacitor array;
The RC oscillator 101 is further configured to adjust the bit of the fine tuning capacitor array according to the fine tuning value to adjust the frequency of the RC oscillating clock RCCLK.
Further, referring to fig. 1, the calibration circuit includes: a reference clock control module 106 for enabling the reference clock module 102 when starting calibration, so that the reference clock module 102 outputs a reference clock; and, after calibration is completed, the reference clock module 102 is turned off.
The embodiment of the invention realizes the calibration of the RC oscillation clock by a reverse-push method. And comparing the reference count value of the reference clock with the actual count value to obtain the frequency deviation of the RC oscillation clock, and converting the frequency deviation into bits which need to be adjusted by the fine-tuning capacitor array.
In one embodiment, RC oscillator 101 outputs a 32.768KHz RC oscillation clock, which may be referred to as RC_32K as a sleep clock, and the reference clock may be a 26MHz system clock, but is not limited thereto, and may be 19.2MHz, 38.3MHz, 52MHz, or the like.
The cycles of the 26MHz clock are counted using several cycles of RC 32K as the time window, i.e. the time window is (1/32K) x N, N being a natural number, such that the minimum deviation of the count of the acquired 26MHz cycles is less than a certain value, such as 60ppm (1 ppm means that every 1 million clocks will produce a deviation of one clock). Taking the sampling deviation and the timing precision into consideration, the minimum deviation can be formulated to be +/-15 ppm (of course, the minimum deviation can be corrected to be finer, but the time cost is increased, and the minimum deviation is balanced according to the actual situation).
By calculation, (1/32K) 84 is taken as a time window, in which the reference count value of the 26MHz cycle count is 66667, and the minimum deviation can be +/-15 ppm. Here, 84 and 66667 may be adjusted according to the actual situation, and may be taken to be large or small. In this embodiment, the actual count value of the 26MHz period differs from the reference count value by 1, and there is a 15ppm frequency deviation for the 32KHz clock. The actual count value and the reference count value of the 26MHz period differ by 2, and the corresponding 32KHz clock has a frequency deviation of 30 ppm. And so on.
Specifically, the following settings were first made:
The frequency deviation corresponding to the unit bit of the fine-tuning capacitor array is recorded as Fre FT ppm/bit, namely, the fine-tuning capacitor array adjusts 1bit to generate Fre FT ppm frequency deviation. The frequency deviation corresponding to the unit count deviation of the reference clock period count is recorded as Fre REF ppm/step, namely the actual count value of the reference clock and the reference count value differ by 1, the frequency deviation of Fre REF ppm is generated, and 1 step is one count deviation.
Based on the above settings, the expression of the frequency deviation of the RC oscillation clock is:
FE1＝∣REAL_NUM1-REF_NUM1∣*FreREF，
Where FE1 represents the frequency deviation of the RC oscillation clock, real_num1 represents the actual count value of the reference clock cycle, ref_num1 represents the reference count value of the reference clock cycle, and Fre REF represents the frequency deviation of the RC oscillation clock corresponding to the unit count deviation of the reference clock cycle.
Further, the method for calculating the fine adjustment value by the calibration module 105 is as follows:
When the actual count value REAL_NUM1 is larger than the reference count value REF_NUM1, the RC oscillation clock frequency is smaller, the period is larger, and then the fine-tuning capacitor array is adjusted upwards (REAL_NUM1-REF_NUM1)/A bits, so that the capacitance value is reduced, and the RC oscillation frequency is increased;
when the actual count value REAL_NUM1 is smaller than the reference count value REF_NUM1, which indicates that the RC oscillation clock frequency is larger and the period is smaller, the fine tuning capacitor array is turned down (REF_NUM1-REAL_NUM1)/A bits to increase the capacitance value, thereby reducing the RC oscillation frequency.
In the above formula, a=fre FT/FreREF, and a needs to be rounded, and rounding is adopted.
Setting: b= (real_num 1-ref_num 1)/a, where B needs to be rounded down, B <1 is taken as 0,1 is less than or equal to B < 2, and 1 is taken as 1.
Similarly, C= (REF_NUM1-REAL_NUM1)/A, where C needs to be rounded down, C <1 is taken as 0,1 is less than or equal to C <2, and 1 is taken as 1.
As a specific example, if the fine-tuning capacitor array is set to adjust 1bit, a frequency deviation of 60ppm is produced. While the count deviation of the 26MHz cycle count is 1 (the actual count value is 66666 or 66668), only a frequency deviation of 15ppm is produced, and then the fine tuning capacitor array does not need to be adjusted. Only if the frequency deviation corresponding to the counting deviation of the 26MHz period count is greater than 60ppm, the fine tuning capacitor array needs to be adjusted.
After accurate RC_32K is obtained by adjusting the fine-tuning capacitor array, clock of an accurate timing module (RTC IP) is obtained by fixing frequency division coefficients, and calendar updating and time synchronization updating are completed.
In another aspect, an embodiment of the present invention provides a calibration circuit for an RC oscillation clock, as shown in fig. 2, the calibration circuit comprising:
The RC oscillator 201 is used for outputting an RC oscillation clock RCCLK, and a fine tuning capacitor array and a coarse tuning capacitor array are arranged in the RC oscillator 201 and are respectively used for fine tuning and coarse tuning the capacitance value of the RC oscillator;
A reference clock module 202 for outputting a reference clock REFCLK;
The second counting module 203 is configured to receive the RC oscillation clock RCCLK and the reference clock REFCLK, count the periods of the RC oscillation clock RCCLK with the periods of the plurality of reference clocks REFCLK as a second time window, and obtain an actual count value real_num2 of the RC oscillation clock;
A second comparing module 204, configured to compare the actual count value real_num2 of the RC oscillation clock with the reference count value ref_num2 of the RC oscillation clock in the second time window, to obtain a frequency deviation FE2 of the RC oscillation clock;
The calibration module 205 is configured to calculate a fine adjustment value according to the frequency deviation FE2 of the RC oscillation clock when the frequency deviation FE2 of the RC oscillation clock is within the adjustable range of the fine adjustment capacitor array;
the RC oscillator 201 is further configured to adjust the bit of the fine tuning capacitor array according to the fine tuning value to adjust the frequency of the RC oscillating clock RCCLK.
Further, referring to fig. 2, the calibration circuit includes: a reference clock control module 206 for enabling the reference clock module 202 when starting calibration, so that the reference clock module 202 outputs a reference clock; and, after calibration is completed, the reference clock module 202 is turned off.
In the embodiment of the invention, the periods of a plurality of reference clocks are used as time windows to directly count the RC oscillation clocks, so that the calibration of the RC oscillation clocks is realized. And comparing the reference count value with the actual count value of the RC oscillation clock to obtain the frequency deviation of the RC oscillation clock, and converting the frequency deviation into bits which need to be adjusted by the fine-tuning capacitor array.
In one embodiment, the RC oscillator 201 outputs an RC oscillation clock of 32.768KHz, which may be used as a sleep clock, denoted as rc_32k, and the reference clock may be a system clock of 26MHz, but is not limited thereto, and may be 19.2MHz, 38.3MHz, 52MHz, or the like. If the system clock of 26MHz is used as the reference clock, the time window is (1/26M) N, N is a natural number.
With reference to the previous embodiments, the following settings were made:
The frequency deviation corresponding to the unit bit of the fine-tuning capacitor array is recorded as Fre FT ppm/bit, namely, the fine-tuning capacitor array adjusts 1bit to generate Fre FT ppm frequency deviation. The frequency deviation corresponding to the unit counting deviation of the RC oscillation clock period count is recorded as Fre RC ppm/step, namely the actual counting value of the RC oscillation clock and the reference counting value are different by 1, the frequency deviation of Fre RC ppm is generated, and 1 step is one counting deviation.
Based on the above settings, the expression of the frequency deviation of the RC oscillation clock is:
FE2＝∣REAL_NUM2-REF_NUM2∣*FreRC，
Where FE2 represents the frequency deviation of the RC oscillation clock, real_num2 represents the actual count value of the RC oscillation clock period, ref_num2 represents the reference count value of the RC oscillation clock period, and Fre RC represents the frequency deviation of the RC oscillation clock corresponding to the unit count deviation of the RC oscillation clock period.
Further, the method for calculating the fine adjustment value by the calibration module 205 is as follows:
When the actual count value REAL_NUm2 of the RC oscillation clock RC_32K is greater than the reference count value REF_NUm2, which means that the RC oscillation clock frequency is greater and the period is smaller, the fine tuning capacitor array is turned down (REAL_NUm2-REF_NUm2)/A bits to increase the capacitance value, thereby reducing the RC oscillation frequency.
When the actual count value REAL_NUm2 of the RC oscillation clock RC_32K is smaller than the reference count value REF_NUm2, which means that the frequency of the RC oscillation clock is smaller and the period is larger, the fine tuning capacitor array is up-tuned (REF_NUm2-REAL_NUm2)/A bits, and the capacitance value is reduced, so that the RC oscillation frequency is increased.
In the above formula, a= FreFT/FreRC, and a needs to be rounded, and rounding is adopted.
Setting: b= (real_num 2-ref_num 2)/a, where B needs to be rounded down, B <1 is taken as 0,1 is less than or equal to B <2, and 1 is taken as 1.
Similarly, C= (REF_NUm2-REAL_NUm2)/A, where C needs to be rounded down, C <1 is taken as 0,1 is less than or equal to C <2, and 1 is taken as 1.
In the above embodiments, the structures of the fine adjustment capacitor array and the coarse adjustment capacitor array are not particularly limited, and it is understood that the structures may be implemented in the form of digital capacitor arrays. Fig. 3 shows a schematic diagram of an internal structure of an RC oscillator, wherein the basic adjustment principle of the fine adjustment capacitor array and the coarse adjustment capacitor array is as follows: the capacitance value of the capacitor array is adjusted by controlling the on-off of a switching tube in the capacitor array. The precision of the coarse tuning capacitor array and the precision of the fine tuning capacitor array can be designed according to a certain ratio, and the fine tuning can cover a certain coarse tuning range.
Further, in one embodiment, the calibration circuit of the RC oscillation clock further includes: the calibration time interval configuration module is used for configuring the time interval of two times of calibration, and specifically comprises the following steps: configuring the time interval of any two times of calibration as fixed time;
Or dynamically configuring the time intervals of the current calibration and the next calibration according to the frequency deviation of the current calibration, shortening the time intervals of the current calibration and the next calibration if the frequency deviation of the current calibration is larger than a set threshold value, and increasing the time intervals of the current calibration and the next calibration or keeping the time intervals unchanged if the frequency deviation of the current calibration is smaller than the set threshold value;
Or according to the frequency deviation of the current calibration, configuring the time intervals of the current calibration and the next calibration as the time interval corresponding to the gear where the frequency deviation is located.
Specifically, the embodiments of the present invention provide three ways to configure the calibration time interval.
In the mode 1, the time interval between two calibration is configured as a fixed time T, and then the frequency of the RC oscillation clock is calibrated at fixed time according to the set fixed time T.
And 2, dynamically configuring the time interval of the two times of calibration according to the frequency deviation of the RC oscillation clock calibrated at the time. Setting a fixed time interval T, waiting for the time interval T after the last calibration is finished, calculating the frequency deviation of RC_32K before the current calibration, and if the frequency deviation is larger than a threshold value TH, shortening the time interval T of the current calibration and the next calibration, and adjusting the time interval T to be T (1-n%). If the frequency deviation is smaller than the threshold TH, this time interval T is maintained or adjusted to T (1+m%). Wherein m and n are configurable.
Mode 3, frequency offset is divided into a plurality of gears, and each gear corresponds to a different time interval. And according to the frequency deviation calculated by the calibration, configuring the time interval of the calibration and the next calibration as the time interval corresponding to the gear where the frequency deviation is located.
Further, in one embodiment, the calibration module 105/205 is configured to calculate a coarse adjustment value according to the frequency deviation of the RC oscillation clock when the frequency deviation of the RC oscillation clock exceeds the adjustable range of the fine adjustment capacitor array;
The RC oscillator is also used for adjusting the bit of the coarse adjustment capacitor array according to the coarse adjustment value, so that after coarse adjustment, the frequency deviation of the RC oscillation clock is within the adjustable range of the fine adjustment capacitor array. The calibration module 105/205 calculates the coarse adjustment value, requiring software involvement.
The adjustment of the coarse tuning capacitor array by default can be written in by calibration in the ATE stage, so that the calibration of the RC oscillation Clock can be realized by adjusting the fine tuning capacitor array, and then the Clock of the accurate timing module (RTC IP) can be obtained through fixing the frequency division coefficient.
However, when the actual count value is greater than or less than the reference count value by more than X counters, that is, when the frequency deviation of rc_32k exceeds the adjustable range of the fine-tuning capacitor array, then the system needs to be awakened by interruption (hardware interruption) and software is involved.
After the configuration value of the coarse tuning capacitor array is obtained after the first starting, the configuration value is stored in a register of the coarse tuning capacitor array, and software receives the interrupt and informs the software of the current deviation direction and the current deviation magnitude of RC_32K;
after receiving the deviation direction and the deviation, the software modifies the register value stored in the coarse adjustment capacitor array, and then enters an SD or UPS mode;
After entering SD or UPS mode, the frequency deviation of RC_32K is recalculated and the fine-tuning capacitor array is adjusted, so that relatively accurate RC_32K is obtained.
According to the calibration circuit for the RC oscillation clock, provided by the embodiment of the invention, a certain time interval is configured periodically or dynamically according to preset conditions, the frequency of the RC oscillation clock is calibrated, two capacitor arrays are adjusted according to the frequency deviation of the RC oscillation clock, one capacitor array is coarse-tuned, and the other capacitor array is fine-tuned, so that the output precision of the RC oscillation clock is improved while the power consumption is saved, and the accurate display time can be ensured when the RC oscillation clock is turned on again under ultra-low power consumption or long-term shutdown.
The following effects can be brought about in particular:
1. Two capacitance arrays with coarse and fine adjustment are arranged in the RC oscillator, and the calibration of the RC oscillation clock is realized by directly adjusting the capacitance arrays arranged in the RC oscillator, so that the precision problem of the RC oscillation clock is solved from the source.
2. The accuracy of the calibration can be improved by counting the cycles of the reference clock (large frequency) with several cycles of the RC oscillating clock (small frequency) as a time window.
3. The frequency deviation caused by temperature drift is integrated, the time interval of two times of calibration before and after is dynamically configured, the calibration frequency is optimized to the greatest extent, and the power consumption can be saved to the greatest extent while the calibration precision is met.
4. The whole process realizes calibration by hardware, only needs software participation when adjusting the coarse capacitance array, and reduces the software participation degree.
5. And the reference clock is enabled during calibration, and is closed after the calibration is completed, so that the power consumption can be saved to the greatest extent.
On the other hand, based on the calibration circuit of the RC oscillation clock in the embodiment of fig. 1, the embodiment of the present invention provides a calibration method of the RC oscillation clock, as shown in fig. 4, where the calibration method includes:
step 401, enabling a reference clock module when starting calibration, so that the reference clock module outputs a reference clock;
Step 402, a first counting module receives an RC oscillation clock and a reference clock, counts the periods of the reference clock with the periods of a plurality of RC oscillation clocks as a first time window, and obtains an actual count value of the reference clock;
Step 403, the first comparing module compares the actual count value of the reference clock with the reference count value of the reference clock in the first time window to obtain the frequency deviation of the RC oscillation clock;
Step 404, when the frequency deviation of the RC oscillation clock is within the adjustable range of the fine tuning capacitor array, the calibration module calculates a fine tuning value according to the frequency deviation of the RC oscillation clock;
step 405, the RC oscillator adjusts the bit of the built-in fine tuning capacitor array according to the fine tuning value to adjust the frequency of the RC oscillation clock;
step 406, the reference clock module is turned off after calibration is completed.
On the other hand, based on the calibration circuit of the RC oscillation clock in the embodiment of fig. 2, an embodiment of the present invention provides a calibration method of the RC oscillation clock, as shown in fig. 5, where the calibration method includes:
Step 501, enabling a reference clock module when starting calibration, so that the reference clock module outputs a reference clock;
step 502, a second counting module receives the RC oscillation clock and the reference clock, and counts the periods of the RC oscillation clock with the periods of the plurality of reference clocks as a second time window to obtain an actual count value of the RC oscillation clock;
step 503, the second comparing module compares the actual count value of the RC oscillation clock with the reference count value of the RC oscillation clock in the second time window, to obtain the frequency deviation of the RC oscillation clock;
Step 504, when the frequency deviation of the RC oscillation clock is within the adjustable range of the fine tuning capacitor array, the calibration module calculates a fine tuning value according to the frequency deviation of the RC oscillation clock;
Step 505, the RC oscillator adjusts the bit of the fine tuning capacitor array according to the fine tuning value to adjust the frequency of the RC oscillating clock;
Step 506, the reference clock module is turned off after calibration is completed.
In the above embodiment, the RC oscillation clock may be a sleep clock of 32.768KHz, and the reference clock may be a system clock of 26 MHz.
In one embodiment, there are three ways to configure the calibration time interval.
Mode 1: the time interval of any two calibrations is configured as a fixed time;
Mode 2: the time interval between the current calibration and the next calibration is dynamically configured according to the frequency deviation of the current calibration, if the frequency deviation of the current calibration is larger than a set threshold value, the time interval between the current calibration and the next calibration is shortened, and if the frequency deviation of the current calibration is smaller than the set threshold value, the time interval between the current calibration and the next calibration is increased or the time interval is kept unchanged.
Mode 3: and according to the frequency deviation of the current calibration, configuring the time intervals of the current calibration and the next calibration as the time interval corresponding to the gear where the frequency deviation is located.
In one embodiment, the calibration module calculates the coarse adjustment value based on the frequency deviation of the RC oscillating clock when the frequency deviation of the RC oscillating clock exceeds the adjustable range of the fine tuning capacitor array. And then the RC oscillator adjusts the bit of the built-in coarse tuning capacitor array according to the coarse tuning value, so that after coarse tuning, the frequency deviation of the RC oscillation clock is within the adjustable range of the fine tuning capacitor array. And then recalculate the frequency deviation of the RC oscillation clock to adjust the fine-tuning capacitor array, thereby obtaining a relatively accurate clock.
The calibration method of the RC oscillation clock provided by the embodiment of the present invention is implemented based on the calibration circuit of the RC oscillation clock of the above embodiment, so that the same technical effects can be produced, and the technical details can be referred to the description of the above calibration circuit embodiment and will not be repeated here.
In another aspect, an embodiment of the present invention provides a chip including the calibration circuit of the RC oscillation clock of the above embodiment.
In another aspect, an embodiment of the present invention provides an electronic device, including the above chip.
The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present invention should be included in the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (12)

1. A calibration circuit for an RC oscillating clock, comprising:
The RC oscillator is used for outputting an RC oscillation clock, and a fine adjustment capacitor array and a coarse adjustment capacitor array are arranged in the RC oscillator and are respectively used for carrying out fine adjustment and coarse adjustment on the capacitance value of the RC oscillator;
The reference clock module is used for outputting a reference clock;
The first counting module is used for receiving the RC oscillation clocks and the reference clocks, and counting the periods of the reference clocks by taking the periods of a plurality of the RC oscillation clocks as a first time window to obtain the actual count value of the reference clocks;
the first comparison module is used for comparing the actual count value of the reference clock with the reference count value of the reference clock in the first time window to obtain the frequency deviation of the RC oscillation clock;
The calibration module is used for calculating a fine adjustment value according to the frequency deviation of the RC oscillation clock when the frequency deviation of the RC oscillation clock is in the adjustable range of the fine adjustment capacitor array;
The RC oscillator is further used for adjusting the bit of the fine-tuning capacitor array according to the fine-tuning value so as to adjust the frequency of the RC oscillation clock;
the method for calculating the fine adjustment value by the calibration module is as follows:
If the actual count value of the reference clock is greater than the base count value of the reference clock, the expression of the fine adjustment value is: b= (real_num 1-ref_num 1)/a, if the actual count value of the reference clock is smaller than the reference count value of the reference clock, the expression of the fine adjustment value is: c= (ref_num 1-real_num 1)/a;
In the above expression, B represents the number of bits that the fine-tuning capacitor array needs to be up-tuned to reduce the capacitance value, C represents the number of bits that the fine-tuning capacitor array needs to be down-tuned to increase the capacitance value, B and C are all rounded down, a=fre FT/FreREF,FreFT represents the frequency deviation corresponding to the unit bits of the fine-tuning capacitor array, fre REF represents the frequency deviation corresponding to the unit count deviation of the reference clock cycle count, real_num1 represents the actual count value of the reference clock, and ref_num1 represents the reference count value of the reference clock.
2. A calibration circuit for an RC oscillating clock, comprising:
The RC oscillator is used for outputting an RC oscillation clock, and a fine adjustment capacitor array and a coarse adjustment capacitor array are arranged in the RC oscillator and are respectively used for carrying out fine adjustment and coarse adjustment on the capacitance value of the RC oscillator;
The reference clock module is used for outputting a reference clock;
the second counting module is used for receiving the RC oscillation clock and the reference clock, counting the periods of the RC oscillation clock by taking a plurality of periods of the reference clock as a second time window, and obtaining an actual count value of the RC oscillation clock;
The second comparison module is used for comparing the actual count value of the RC oscillation clock with the reference count value of the RC oscillation clock in the second time window to obtain the frequency deviation of the RC oscillation clock;
The calibration module is used for calculating a fine adjustment value according to the frequency deviation of the RC oscillation clock when the frequency deviation of the RC oscillation clock is in the adjustable range of the fine adjustment capacitor array;
The RC oscillator is further used for adjusting the bit of the fine-tuning capacitor array according to the fine-tuning value so as to adjust the frequency of the RC oscillation clock;
the method for calculating the fine adjustment value by the calibration module is as follows:
If the actual count value of the RC oscillation clock is greater than the reference count value of the RC oscillation clock, the expression of the fine adjustment value is: b= (real_num 2-ref_num 2)/a, if the actual count value of the RC oscillation clock is smaller than the reference count value of the RC oscillation clock, the expression of the fine adjustment value is: c= (ref_num2-real_num2)/a;
In the above expression, B represents the number of bits that the fine-tuning capacitor array needs to down-regulate to increase the capacitance value, C represents the number of bits that the fine-tuning capacitor array needs to up-regulate to decrease the capacitance value, B and C are all rounded down, a=fre FT/FreRC,FreFT represents the frequency deviation corresponding to the unit bit of the fine-tuning capacitor array, fre RC represents the frequency deviation corresponding to the unit count deviation of the RC oscillation clock cycle count, real_num2 represents the actual count value of the RC oscillation clock, and ref_num2 represents the reference count value of the RC oscillation clock.
3. The calibration circuit of an RC oscillating clock according to claim 1 or 2, wherein the RC oscillating clock is a sleep clock of 32.768 KHz.
4. The calibration circuit of an RC oscillating clock according to claim 1 or 2, wherein the calibration circuit further comprises:
The calibration time interval configuration module is used for configuring the time interval of two times of calibration, and specifically comprises the following steps: configuring the time interval of any two times of calibration as fixed time;
Or dynamically configuring the time intervals of the current calibration and the next calibration according to the frequency deviation of the current calibration, shortening the time intervals of the current calibration and the next calibration if the frequency deviation of the current calibration is larger than a set threshold value, and increasing the time intervals of the current calibration and the next calibration or keeping the time intervals unchanged if the frequency deviation of the current calibration is smaller than the set threshold value;
Or according to the frequency deviation of the current calibration, configuring the time intervals of the current calibration and the next calibration as the time interval corresponding to the gear where the frequency deviation is located.
5. The calibration circuit of an RC oscillating clock according to claim 1 or 2, wherein the calibration module is further configured to calculate a coarse adjustment value according to the frequency deviation of the RC oscillating clock when the frequency deviation of the RC oscillating clock exceeds the adjustable range of the fine adjustment capacitor array;
The RC oscillator is further used for adjusting the bit of the coarse adjustment capacitor array according to the coarse adjustment value, so that after coarse adjustment, the frequency deviation of the RC oscillation clock is within the adjustable range of the fine adjustment capacitor array.
6. A method of calibrating an RC oscillating clock, implemented based on the calibration circuit of the RC oscillating clock of claim 1, the method comprising:
enabling a reference clock module when starting calibration, so that the reference clock module outputs a reference clock;
The first counting module receives the RC oscillation clocks and the reference clocks, and counts the periods of the reference clocks by taking the periods of a plurality of the RC oscillation clocks as a first time window to obtain actual count values of the reference clocks;
The first comparison module compares the actual count value of the reference clock with the reference count value of the reference clock in the first time window to obtain the frequency deviation of the RC oscillation clock;
when the frequency deviation of the RC oscillation clock is in the adjustable range of the fine-tuning capacitor array, the calibration module calculates to obtain a fine-tuning value according to the frequency deviation of the RC oscillation clock;
The RC oscillator adjusts the bit of the built-in fine-tuning capacitor array according to the fine tuning value so as to adjust the frequency of the RC oscillation clock;
and closing the reference clock module after the calibration is completed.
7. A method of calibrating an RC oscillating clock, implemented based on the calibration circuit of the RC oscillating clock of claim 2, the method comprising:
enabling a reference clock module when starting calibration, so that the reference clock module outputs a reference clock;
The second counting module receives the RC oscillation clock and the reference clock, and counts the periods of the RC oscillation clock by taking the periods of a plurality of the reference clocks as a second time window to obtain an actual count value of the RC oscillation clock;
The second comparison module compares the actual count value of the RC oscillation clock with the reference count value of the RC oscillation clock in the second time window to obtain the frequency deviation of the RC oscillation clock;
when the frequency deviation of the RC oscillation clock is in the adjustable range of the fine-tuning capacitor array, the calibration module calculates to obtain a fine-tuning value according to the frequency deviation of the RC oscillation clock;
The RC oscillator adjusts the bit of the fine-tuning capacitor array according to the fine-tuning value so as to adjust the frequency of the RC oscillation clock;
and closing the reference clock module after the calibration is completed.
8. The method of calibrating an RC oscillating clock according to claim 6 or 7, wherein the RC oscillating clock is a sleep clock of 32.768 KHz.
9. The method of calibrating an RC oscillating clock according to claim 6 or 7, wherein the time interval of any two calibrations is configured as a fixed time;
Or dynamically configuring the time interval of the current calibration and the next calibration according to the frequency deviation of the current calibration, if the frequency deviation of the current calibration is larger than a set threshold value, shortening the time interval of the current calibration and the next calibration, and if the frequency deviation of the current calibration is smaller than the set threshold value, increasing the time interval of the current calibration and the next calibration or keeping the time interval unchanged;
Or according to the frequency deviation of the current calibration, configuring the time intervals of the current calibration and the next calibration as the time interval corresponding to the gear where the frequency deviation is located.
10. The method of calibrating an RC oscillating clock according to claim 6 or 7, further comprising:
When the frequency deviation of the RC oscillation clock exceeds the adjustable range of the fine-tuning capacitor array, the calibration module calculates a coarse tuning value according to the frequency deviation of the RC oscillation clock;
The RC oscillator adjusts the bit of the built-in coarse tuning capacitor array according to the coarse tuning value, so that after coarse tuning, the frequency deviation of the RC oscillation clock is within the adjustable range of the fine tuning capacitor array.
11. A chip comprising a calibration circuit for an RC oscillating clock as claimed in any one of claims 1 to 5.
12. An electronic device comprising the chip of claim 11.
CN202310361829.3A 2023-03-30 2023-03-30 Calibration circuit, calibration method, chip and electronic equipment of RC oscillation clock Active CN116318120B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310361829.3A CN116318120B (en) 2023-03-30 2023-03-30 Calibration circuit, calibration method, chip and electronic equipment of RC oscillation clock

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310361829.3A CN116318120B (en) 2023-03-30 2023-03-30 Calibration circuit, calibration method, chip and electronic equipment of RC oscillation clock

Publications (2)

Publication Number Publication Date
CN116318120A CN116318120A (en) 2023-06-23
CN116318120B true CN116318120B (en) 2024-05-03

Family

ID=86779862

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310361829.3A Active CN116318120B (en) 2023-03-30 2023-03-30 Calibration circuit, calibration method, chip and electronic equipment of RC oscillation clock

Country Status (1)

Country Link
CN (1) CN116318120B (en)

Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR19990079416A (en) * 1998-04-06 1999-11-05 리차드 치앙 Method and apparatus for adjusting frequency of oscillator mounted in integrated circuit
US6545950B1 (en) * 2000-05-16 2003-04-08 Ericsson Inc. Methods, systems, wireless terminals, and computer program products for calibrating an electronic clock using a base reference signal and a non-continuous calibration reference signal having greater accuracy than the base reference signal
CN101247123A (en) * 2007-10-24 2008-08-20 吴明星 Single-chip system clock calibration method
CN101257302A (en) * 2007-02-27 2008-09-03 北京朗波芯微技术有限公司 Frequency adjusting method of oscillator and decimal fraction frequency dividing phase-locked loop frequency synthesizer
CN101753287A (en) * 2008-11-28 2010-06-23 上海芯略电子科技有限公司 Fully-digital and fully-integrated comprehensive frequency generator and method
WO2015085825A1 (en) * 2013-12-10 2015-06-18 炬芯（珠海）科技有限公司 Frequency calibration methods and apparatus
CN106130547A (en) * 2016-06-20 2016-11-16 大唐微电子技术有限公司 A kind of clock frequency calibration steps and device
CN108063617A (en) * 2017-11-20 2018-05-22 珠海慧联科技有限公司 The clock frequency calibration method and system of a kind of low frequency RC oscillators
CN110212913A (en) * 2019-06-24 2019-09-06 广东高云半导体科技股份有限公司 The calibration method of phaselocked loop and its voltage controlled oscillator
CN110492848A (en) * 2019-08-15 2019-11-22 成都锐成芯微科技股份有限公司 The number adjustment device and its method of adjustment of RC oscillator
US10530372B1 (en) * 2016-03-25 2020-01-07 MY Tech, LLC Systems and methods for digital synthesis of output signals using resonators
CN111431526A (en) * 2020-04-17 2020-07-17 珠海泰特微电子股份有限公司 High-precision oscillator calibration system and rapid calibration method thereof
CN111541450A (en) * 2020-06-19 2020-08-14 华大半导体有限公司 Automatic clock calibration circuit and method
CN111934678A (en) * 2020-09-28 2020-11-13 深圳英集芯科技有限公司 Method for automatically calibrating clock frequency in chip and related product
CN112636752A (en) * 2020-12-29 2021-04-09 北京奕斯伟计算技术有限公司 Oscillator device and oscillator frequency calibration method
CN114050790A (en) * 2021-11-05 2022-02-15 天津兆讯电子技术有限公司 High-precision automatic calibration method and device for RC oscillator

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6639479B2 (en) * 2002-01-18 2003-10-28 Broadcom Corporation Highly stable integrated time reference
EP1943737B1 (en) * 2005-11-04 2018-12-05 Skyworks Solutions, Inc. High resolution auto-tuning for a voltage controlled oscillator
US7474159B2 (en) * 2007-05-08 2009-01-06 Zerog Wireless, Inc. Frequency calibration for frequency synthesizers
US9438164B2 (en) * 2013-12-30 2016-09-06 Sandisk Technologies Llc System and method for calibrating capacitor-based oscillators in crystal-less devices
EP2978133A1 (en) * 2014-07-22 2016-01-27 Synopsys, Inc. Calibration unit for calibrating an oscillator, oscillator arrangement and method for calibrating an oscillator
US10103740B2 (en) * 2015-11-02 2018-10-16 Nxp Usa, Inc. Method and apparatus for calibrating a digitally controlled oscillator
TWI730523B (en) * 2019-12-03 2021-06-11 智成電子股份有限公司 Self-calibration system single chip

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR19990079416A (en) * 1998-04-06 1999-11-05 리차드 치앙 Method and apparatus for adjusting frequency of oscillator mounted in integrated circuit
US6545950B1 (en) * 2000-05-16 2003-04-08 Ericsson Inc. Methods, systems, wireless terminals, and computer program products for calibrating an electronic clock using a base reference signal and a non-continuous calibration reference signal having greater accuracy than the base reference signal
CN101257302A (en) * 2007-02-27 2008-09-03 北京朗波芯微技术有限公司 Frequency adjusting method of oscillator and decimal fraction frequency dividing phase-locked loop frequency synthesizer
CN101247123A (en) * 2007-10-24 2008-08-20 吴明星 Single-chip system clock calibration method
CN101753287A (en) * 2008-11-28 2010-06-23 上海芯略电子科技有限公司 Fully-digital and fully-integrated comprehensive frequency generator and method
WO2015085825A1 (en) * 2013-12-10 2015-06-18 炬芯（珠海）科技有限公司 Frequency calibration methods and apparatus
US10530372B1 (en) * 2016-03-25 2020-01-07 MY Tech, LLC Systems and methods for digital synthesis of output signals using resonators
CN106130547A (en) * 2016-06-20 2016-11-16 大唐微电子技术有限公司 A kind of clock frequency calibration steps and device
CN108063617A (en) * 2017-11-20 2018-05-22 珠海慧联科技有限公司 The clock frequency calibration method and system of a kind of low frequency RC oscillators
CN110212913A (en) * 2019-06-24 2019-09-06 广东高云半导体科技股份有限公司 The calibration method of phaselocked loop and its voltage controlled oscillator
CN110492848A (en) * 2019-08-15 2019-11-22 成都锐成芯微科技股份有限公司 The number adjustment device and its method of adjustment of RC oscillator
CN111431526A (en) * 2020-04-17 2020-07-17 珠海泰特微电子股份有限公司 High-precision oscillator calibration system and rapid calibration method thereof
CN111541450A (en) * 2020-06-19 2020-08-14 华大半导体有限公司 Automatic clock calibration circuit and method
CN111934678A (en) * 2020-09-28 2020-11-13 深圳英集芯科技有限公司 Method for automatically calibrating clock frequency in chip and related product
CN112636752A (en) * 2020-12-29 2021-04-09 北京奕斯伟计算技术有限公司 Oscillator device and oscillator frequency calibration method
CN114050790A (en) * 2021-11-05 2022-02-15 天津兆讯电子技术有限公司 High-precision automatic calibration method and device for RC oscillator

Also Published As

Publication number Publication date
CN116318120A (en) 2023-06-23

Similar Documents

Publication Publication Date Title
KR101651263B1 (en) Automatic synchronization of an internal oscillator to an external frequency reference
US8237482B2 (en) Circuit and method for generating a clock signal
KR101126093B1 (en) Monolithic clock generator and timing/frequency reference
KR100782796B1 (en) Rc oscillation circuit capable of adjusting oscillation frequency and method of the same
US9432034B2 (en) Low-power oscillator
CN107026645B (en) Frequency correction circuit and frequency correction method
CN109067394B (en) On-chip clock calibration device and calibration method
CN1436402A (en) Calibration device and method for generating clock pulse in integrated circuit
TW201526548A (en) Improved low-power oscillator
CN116318120B (en) Calibration circuit, calibration method, chip and electronic equipment of RC oscillation clock
JP2000174615A (en) Method and device for automatically correcting internal clock frequency of integrated circuit
US6747374B2 (en) Circuit for correcting deviation in oscillating frequency
CN103501178A (en) High-stability time base oscillator automatic calibration circuit and method
CN210490799U (en) SoC built-in oscillating circuit
CN111010174A (en) Method and circuit for improving time-keeping metering precision
JP2004072289A (en) Frequency adjusting circuit
CN105116712A (en) Method for automatically calibrating built-in crystal oscillator
CN114785342A (en) Low-frequency high-precision oscillator for system-on-chip SOC and system-on-chip SOC
CN115699583A (en) Radio device with resonator
US4730286A (en) Circuit and method for correcting the rate of an electronic timepiece
JP2003270369A (en) Time correction method and time correction device for real time clock
Lin et al. A±20-ppm-50° C-105° C 1-µA 32.768-kHz Clock Generator with a System-HFXO-Assisted Background Calibration
Chen et al. A 20.9-nW 32.768-kHz Real-Time Clock with 2.2-ppm Temperature Stability for Outdoor Wireless IoT Application
CN110729985B (en) Clock signal generation circuit and electronic equipment
CN116388749A (en) Clock calibration circuit, clock circuit and clock circuit calibration method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant