Real-time clock chip and temperature compensation method of real-time clock chip

Abstract

The invention provides a real-time clock chip and a temperature compensation method of the real-time clock chip. The real-time clock chip comprises an oscillator, a temperature monitoring module and a frequency adjusting module. The frequency adjusting module comprises a first variable capacitor with negative voltage correlation and a second variable capacitor with positive voltage correlation; the first variable capacitor and the second variable capacitor are connected in parallel to input and output electrodes of the oscillator; the temperature monitoring module is used for monitoring the working temperature of the real-time clock chip and transmitting control voltage positively correlated with the working temperature to the frequency adjusting module; and the frequency adjusting module is used for comparing the control voltage with the reference voltage and enabling the corresponding variable capacitor according to the comparison result. According to the embodiment of the invention, the method can guarantee that the output clock has the hour clock offset error in the target temperature range in a segmented temperature compensation mode, so as to achieve an ideal temperature compensation effect.

Description

Technical Field

[0001] The present application relates to the technical field of electronic oscillators, and in particular to a real-time clock chip and a temperature compensation method for the real-time clock chip. Background Art

[0002] Real-time clock (RTC) chips provide accurate time references for electronic systems and are one of the most widely used consumer electronic products. Improving the clock accuracy of real-time clock chips has important research significance and economic value. Real-time clock chips mostly use high-precision crystal oscillators as clock sources, and have an internal frequency calibration circuit to calibrate the frequency error. Since the crystal oscillation frequency will drift with temperature, the real-time clock chip module will produce timing errors with temperature changes. The internal frequency calibration circuit added to the chip is mainly based on temperature compensation function. The goal is to control the frequency error of the crystal oscillator within the full temperature range and control it within a certain range such as ±5ppm (five parts per million), which can ensure that the timing accuracy error of a day is within 0.5 seconds.

[0003] Conventional real-time clock chip temperature compensation adopts the method of temperature sensing circuit + digital compensation circuit. The compensation circuit is usually composed of temperature sensing circuit, analog-to-digital conversion unit, digital polynomial mapping table, digital-to-analog conversion unit, and variable capacitor. Since only one variable capacitor is used, in order to meet the error control requirements within the full temperature range, it is necessary to improve the accuracy of the temperature sensing circuit, analog-to-digital conversion unit, and digital-to-analog conversion unit at the same time, thereby increasing the overall design complexity. Under the same design requirements, the cost is high and it is difficult to meet the low-cost design goal. Summary of the invention

[0004] In view of this, the present application proposes a real-time clock chip and a temperature compensation method for a real-time clock chip to solve the problem in the related art that due to the use of only one variable capacitor, in order to meet the error control requirements within the full temperature range, it is necessary to simultaneously improve the accuracy of the temperature sensing circuit, the analog-to-digital conversion unit and the digital-to-analog conversion unit, thereby increasing the overall design complexity.

[0005] The first aspect of the present application provides a real-time clock chip, including an oscillator, a temperature monitoring module and a frequency adjustment module; the frequency adjustment module includes a first variable capacitor with negative voltage correlation and a second variable capacitor with positive voltage correlation; the first variable capacitor and the second variable capacitor are connected in parallel to the input and output poles of the oscillator;

[0006] A temperature monitoring module, used to monitor the operating temperature of the real-time clock chip and transmit a control voltage positively correlated with the operating temperature to the frequency adjustment module;

[0007] The frequency adjustment module is used to compare the control voltage with a reference voltage and enable a corresponding variable capacitor according to the comparison result.

[0008] The disclosed embodiment uses two variable capacitors with different change characteristics to adjust the frequency of the crystal oscillator. The capacitance of the variable capacitor is controlled by the voltage output by the temperature monitoring circuit. This method can adjust the output frequency of the circuit in real time to resist the temperature change characteristics of the quartz crystal oscillator, ensuring that the output clock has a small clock offset error within the target temperature range, so as to achieve an ideal temperature compensation effect.

[0009] In an embodiment of the present application, the frequency adjustment module is further used to enable the first variable capacitor if the control voltage is greater than the reference voltage; and to enable the second variable capacitor if the control voltage is less than or equal to the reference voltage.

[0010] In the embodiment of the present application, the negative voltage correlation means that the capacitance value of the first variable capacitor increases with the increase of the control voltage, and the positive voltage correlation means that the capacitance value of the second variable capacitor decreases with the increase of the control voltage.

[0011] In an embodiment of the present application, the frequency adjustment module includes a comparator, a first switch connected in series with the first variable capacitor, and a second switch connected in series with the second variable capacitor;

[0012] The first input end of the comparator is connected to a reference voltage, and the second input end is connected to the output end of the temperature monitoring module; the output end of the comparator is connected to the control input end of the first switch and the control input end of the second switch; the output end of the temperature monitoring module serves as the control voltage of the first variable capacitor and the second variable capacitor, and is respectively connected to the control input end of the first variable capacitor and the control input end of the second variable capacitor.

[0013] In an embodiment of the present application, the oscillator includes a dynamic capacitor, a dynamic inductor and a dynamic resistor connected in series, and a static capacitor connected in parallel with the dynamic capacitor, the dynamic inductor and the dynamic resistor.

[0014] The embodiment of the second aspect of the present application provides a temperature compensation method for a real-time clock chip, the method is implemented based on the real-time clock chip described in the embodiment of the first aspect above; the method comprises:

[0015] Monitoring the operating temperature of the real-time clock chip and determining a control voltage positively correlated with the operating temperature;

[0016] If the control voltage is greater than the reference voltage, the first variable capacitor is enabled; if the control voltage is less than or equal to the reference voltage, the second variable capacitor is enabled.

[0017] An embodiment of a third aspect of the present application provides a temperature compensation device for a real-time clock chip, comprising:

[0018] A control voltage determination module, used for monitoring the operating temperature of the real-time clock chip and determining a control voltage positively correlated with the operating temperature;

[0019] The variable capacitor enabling module is used to enable the first variable capacitor if the control voltage is greater than the reference voltage; and to enable the second variable capacitor if the control voltage is less than or equal to the reference voltage.

[0020] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present application. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings.

[0022] In the attached picture:

[0023] Figure 1 A schematic diagram of the structure of a real-time clock chip provided in one embodiment of the present application is shown;

[0024] Figure 2 A schematic diagram showing the relationship between oscillator temperature and frequency deviation provided in an embodiment of the present application is shown;

[0025] Figure 3 A schematic diagram showing an equivalent circuit model of a real-time clock circuit provided in an embodiment of the present application is shown;

[0026] Figure 4 A schematic flow chart of a temperature compensation method for a real-time clock chip provided in an embodiment of the present application is shown;

[0027] Figure 5 A schematic structural diagram of a temperature compensation device for a real-time clock chip provided in one embodiment of the present application is shown. DETAILED DESCRIPTION

[0028] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0029] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by technicians in the field to which this application belongs.

[0030] The following describes the technical scenarios involved in the embodiments of the present application.

[0031] Conventional real-time clock chip temperature compensation adopts the method of temperature sensing circuit + digital compensation circuit. The compensation circuit is usually composed of temperature sensing circuit, analog-to-digital conversion unit, digital polynomial mapping table, digital-to-analog conversion unit, and variable capacitor. Since only one variable capacitor is used, in order to meet the error control requirements within the full temperature range, it is necessary to improve the accuracy of the temperature sensing circuit, analog-to-digital conversion unit, and digital-to-analog conversion unit at the same time, thereby increasing the overall design complexity. Due to the use of multiple modules, the final real-time clock chip integrated circuit implementation area is also large, and the implementation cost is high. In order to reduce costs, the implementation method of the circuit can be changed, and a segmented temperature compensation method can be used.

[0032] Based on the above technical problems, the present application adopts a temperature monitoring circuit to replace the original temperature sensing circuit, and the output is an analog voltage value Vo, which directly controls the variable capacitor at the back end, eliminating the analog-to-digital conversion unit and the digital-to-analog conversion unit. At the same time, two variable capacitors with different temperature correlations are used to replace the original variable capacitor with a single temperature correlation. A single capacitor only needs to work in a temperature range within the full temperature range, and the adjustable temperature range is narrower, and the adjustment accuracy of a single capacitor can be higher.

[0033] Embodiment 1:

[0034] A real-time clock chip is provided in an embodiment of the present application. Figure 1 is a schematic diagram of the structure of a real-time clock chip according to an embodiment of the present application, such as Figure 1 As shown, the real-time clock chip includes: an oscillator, a temperature monitoring module and a frequency adjustment module; wherein the oscillator includes but is not limited to a crystal oscillator;

[0035] The temperature monitoring module is used to monitor the operating temperature of the real-time clock chip and transmit a control voltage positively correlated with the operating temperature to the frequency adjustment module.

[0036] In the embodiment of the present disclosure, the control voltage Vo output by the temperature monitoring circuit has a positive correlation with the temperature and increases monotonically with the increase of the temperature.

[0037] The frequency adjustment module is used to compare the control voltage with a reference voltage and enable a corresponding variable capacitor according to the comparison result.

[0038] In the embodiment of the present disclosure, the frequency adjustment module includes a first variable capacitor with negative voltage correlation and a second variable capacitor with positive voltage correlation; the first variable capacitor and the second variable capacitor are connected in parallel to the input and output poles of the oscillator. The negative voltage correlation means that the capacitance value of the first variable capacitor increases with the increase of the control voltage, and the positive voltage correlation means that the capacitance value of the second variable capacitor decreases with the increase of the control voltage.

[0039] In the embodiments of the present disclosure, for example Figure 1 As shown: the first variable capacitor C1 is connected to the circuit after being selected by the selection switch 1. After being connected to the circuit, its capacitance value is controlled by the control voltage Vo output by the temperature monitoring circuit. The larger the control voltage Vo, the larger the capacitance value of the first variable capacitor C1. Similarly, the second variable capacitor C2 is connected to the circuit after being selected by the selection switch 2. After being connected to the circuit, its capacitance value is controlled by the control voltage Vo output by the temperature monitoring circuit. The larger the control voltage Vo, the smaller the capacitance value of the second variable capacitor C2.

[0040] In some specific embodiments, the frequency adjustment module is further used to enable the first variable capacitor if the control voltage is greater than the reference voltage; and enable the second variable capacitor if the control voltage is less than or equal to the reference voltage.

[0041] In the embodiments of the present disclosure, for example Figure 1 As shown in the figure: when the control voltage Vo>reference voltage Vref, the gating switch 1 is enabled, so that the first variable capacitor C1 is connected in parallel with the oscillator for temperature compensation; when the control voltage Vo≤reference voltage Vref, the gating switch 2 is enabled, so that the second variable capacitor C2 is connected in parallel with the oscillator for temperature compensation. Among them, only one gating switch can be selected at a time, so only one variable capacitor can be selected at a time.

[0042] In some embodiments, the reference voltage Vref is 25°C.

[0043] In the embodiment of the present disclosure, taking a typical AT-cut quartz crystal oscillator as an example, its frequency output curve can be approximated by a quadratic equation:

[0044] f(T)=f o *[1-k(TT o ) 2 ]

[0045] where f o =32.768KHz, T o =25℃, k=0.04ppm / ℃2. Taking 25℃ as the dividing point, the temperature compensation circuit can be divided into two parts. When <25℃, the frequency deviation decreases with the increase of temperature; when >25℃, the frequency deviation increases with the increase of temperature, for example Figure 2 shown.

[0046] In some specific embodiments, the frequency adjustment module includes a comparator, a first switch connected in series with the first variable capacitor, and a second switch connected in series with the second variable capacitor; the first input end of the comparator is connected to a reference voltage, and the second input end is connected to the output end of the temperature monitoring module; the output end of the comparator is connected to the control input end of the first switch and the control input end of the second switch; the output end of the temperature monitoring module serves as the control voltage of the first variable capacitor and the second variable capacitor, and is respectively connected to the control input end of the first variable capacitor and the control input end of the second variable capacitor.

[0047] In the embodiment of the present disclosure, the first input terminal of the comparator is connected to the reference voltage, and the second input terminal is connected to the output terminal of the temperature monitoring module, so when the control voltage Vo output by the temperature monitoring module is greater than the reference voltage Vref, the comparator outputs a high level, thereby enabling the first switch 1 to be turned on. Conversely, when the control voltage Vo output by the temperature monitoring module is less than or equal to the reference voltage Vref, the comparator outputs a low level, thereby enabling the second switch 2 to be turned on.

[0048] The disclosed embodiment can achieve the following objectives through the structure of the comparator and the switch: when the control voltage Vo> the reference voltage Vref, the first variable capacitor C1 is connected in parallel with the oscillator for temperature compensation; when the control voltage Vo≤ the reference voltage Vref, the second variable capacitor C2 is connected in parallel with the oscillator for temperature compensation. The disclosed embodiment can also achieve the above objectives through other structures, which are not specifically limited here.

[0049] In some specific embodiments, for example Figure 3 As shown: the oscillator includes a dynamic capacitor Cm, a dynamic inductor Lm and a dynamic resistor Rm connected in series, and a static capacitor C0 connected in parallel with the dynamic capacitor, the dynamic inductor and the dynamic resistor.

[0050] In the disclosed embodiment, Figure 3 The dotted box in the figure is the oscillator equivalent circuit, Cp is the parasitic capacitance caused by the circuit pins and wires, usually around 2-3pF, and CL is the variable capacitor that needs to be designed (such as the first variable capacitor and the second variable capacitor mentioned above).

[0051] After temperature compensation through the above structure, the output frequency of the real-time clock chip is as follows:

[0052]

[0053] Among them, f o represents the output frequency of the oscillator after temperature compensation, f s Indicates the fundamental frequency of the oscillator.

[0054] In some specific embodiments, the first variable capacitor uses a standard varactor to operate in an accumulation mode, the capacitance value has a positive voltage correlation, and the capacitance value of the capacitor increases with the increase of voltage; the second variable capacitor is an NMOS varactor implemented in a deep N well and operates as an inversion mode capacitor.

[0055] The disclosed embodiment connects the first variable capacitor and the second variable capacitor in parallel to the input and output poles of the oscillator, and enables the corresponding capacitor and controls its capacitance by comparing the magnitude relationship between the control voltage and the reference voltage to adjust the output of the oscillator and ensure that the output clock Co operates within the allowable error range.

[0056] Embodiment 2:

[0057] The disclosed embodiment provides a low-cost real-time clock temperature compensation method, which uses a segmented temperature compensation method to replace the traditional clock temperature compensation method that relies on a lookup table. Two variable capacitors with different change characteristics are used to adjust the frequency of the crystal oscillator, and the capacitance of the variable capacitor is controlled by the voltage output by the temperature monitoring circuit. This method can adjust the output frequency of the circuit in real time to resist the temperature change characteristics of the quartz crystal oscillator, and ensure that the output clock has a small clock offset error within the target temperature range to achieve an ideal temperature compensation effect.

[0058] The disclosed embodiment uses a temperature monitoring circuit to replace the original temperature sensing circuit, and the output is an analog voltage value Vo, which directly controls the variable capacitor at the back end, eliminating the analog-to-digital conversion unit and the digital-to-analog conversion unit. At the same time, two variable capacitors with different temperature correlations are used to replace the original variable capacitor with a single temperature correlation. A single capacitor only needs to work in a temperature range within the full temperature range, and the adjustable temperature range is narrower, and the adjustment accuracy of a single capacitor can be higher.

[0059] The working process of the real-time clock temperature compensation method is as follows: Figure 1 As shown:

[0060] The temperature monitoring circuit is used to monitor the operating temperature of the chip and output a voltage Vo that is positively correlated with the temperature;

[0061] Considering that the temperature characteristic of the crystal oscillator is a quadratic function of an inverted parabola, the output frequency of the crystal oscillator is a maximum value of 32.768KHz at room temperature of 25℃. The frequency deviations of other temperature points increase successively with 25℃ as the center. Set Vref to the Vo reference value corresponding to 25℃. When Vo>Vref, it means that the temperature is greater than 25℃, enable the negative voltage-dependent variable capacitor C1, and turn on the gate switch 1; otherwise, turn off the switch 1 and turn on the gate switch 2;

[0062] The variable capacitor is connected in parallel to the input and output poles of the crystal oscillator, and the capacitance of the capacitor is controlled by Vo to adjust the output of the crystal oscillator to ensure that the output clock Co operates within the allowable error range. Specific implementation method:

[0064] Taking a typical AT-cut quartz crystal oscillator as an example, its frequency output curve can be approximated by a quadratic equation:

[0065] f(T)=f o *[1-k(TT o ) 2 ] (1)

[0066] where f o =32.768KHz, T o =25℃, k=0.04ppm / ℃2. Taking 25℃ as the dividing point, the temperature compensation circuit can be divided into two parts. When <25℃, the frequency deviation decreases with the increase of temperature; when >25℃, the frequency deviation increases with the increase of temperature. The curve is as follows Figure 2 As shown:

[0067] The equivalent model of the real-time clock circuit is as follows Figure 3 As shown, the dotted box is the crystal oscillator equivalent circuit, Cp is the parasitic capacitance caused by the circuit pins and wires, usually around 2-3pF, and CL is the variable capacitor that needs to be designed.

[0068] Assume that the fundamental frequency of the crystal is f s , the output frequency of the above real-time clock circuit is f o , then f o With f s There are the following relationships:

[0069]

[0070] Take a typical 32.768kHz quartz crystal as an example, Cm is in the fF level, C0 is in the pF level, and Cp is 6.25pF. To design a temperature compensation circuit for a real-time clock chip with this crystal as the core, you need to follow these steps:

[0071] According to the temperature error range of fs and the final error range, the capacitance range of the variable capacitor CL is calculated to provide target parameters for the subsequent design of C1 and C2. s The temperature deviation is +-100ppm, Cm = 3fF, c0 = 1pF, Cp = 6.25pF, then the final calculated variable capacitance value is preferably in the range of 0 to 3.5pF;

[0072] Design C1 and C2 based on the calculated variable capacitance values. C1 has a negative voltage correlation, that is, it decreases as the voltage increases, and is selected when the temperature is higher than 25°C. From the above formula 1, it can be obtained that when the temperature is higher than 25°C, Vo increases with the increase of temperature. At this time, C1 decreases with the increase of Vo, which will cause fo to increase with the increase of Vo, thereby compensating for the output clock that deviates from the target frequency due to the increase in temperature, and controlling the error to within 5ppm. Similarly, when the temperature is lower than 25°C, C2 is selected, and Vo decreases as the temperature decreases, causing C2 to increase as the voltage decreases, which brings fo to increase as Vo decreases, compensating for the decrease in output clock frequency caused by the decrease in temperature.

[0073] C1 is a negative voltage dependent capacitor that can be implemented using a standard varactor and works as an accumulation mode capacitor. C2 is a positive voltage dependent capacitor that is an NMOS varactor implemented in a deep N well and works as a reversal mode capacitor.

[0074] The above C1 and C2 are controlled, and the matching temperature monitoring circuit and comparator circuit are designed and adjusted to ensure that the output voltage Vo of the temperature monitoring circuit and the output of the comparator circuit can meet the capacitance change requirements of the variable capacitance diode arrays C1 and C2, thereby playing a real-time compensation role for the crystal oscillator.

[0075] Embodiment 3:

[0076] Corresponding to the above implementation of the real-time clock chip, the embodiment of the present application also provides a temperature compensation method for the real-time clock chip. Figure 4 As shown, the temperature compensation method of the real-time clock chip includes:

[0077] Step S201, monitoring the operating temperature of the real-time clock chip, and determining a control voltage positively correlated with the operating temperature;

[0078] Step S202: if the control voltage is greater than the reference voltage, enabling the first variable capacitor; if the control voltage is less than or equal to the reference voltage, enabling the second variable capacitor.

[0079] The specific implementation method of the embodiment of the present disclosure can refer to the above-mentioned embodiments 1 and 2, which will not be described in detail here.

[0080] Embodiment 4:

[0081] Corresponding to the implementation of the temperature compensation method of the real-time clock chip above, the embodiment of the present application also provides a temperature compensation device for the real-time clock chip. Figure 5 As shown, the temperature compensation device of the real-time clock chip includes:

[0082] A control voltage determination module, used for monitoring the operating temperature of the real-time clock chip and determining a control voltage positively correlated with the operating temperature;

[0083] The variable capacitor enabling module is used to enable the first variable capacitor if the control voltage is greater than the reference voltage; and to enable the second variable capacitor if the control voltage is less than or equal to the reference voltage.

[0084] The temperature compensation device of the real-time clock chip provided in the above-mentioned embodiment of the present application and the temperature compensation method of the real-time clock chip provided in the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the methods adopted, run or implemented by the application programs stored therein.

[0085] It should be noted that:

[0086] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known structures and technologies are not shown in detail so as not to obscure the understanding of this description.

[0087] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various inventive aspects, in the above description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be interpreted as reflecting the following schematic diagram: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the claims below, the inventive aspects are less than all the features of the single embodiment disclosed above. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0088] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

[0089] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A real-time clock chip, characterized in that: The real-time clock chip includes an oscillator, a temperature monitoring module and a frequency adjustment module; the frequency adjustment module includes a first variable capacitor with negative voltage correlation and a second variable capacitor with positive voltage correlation; the first variable capacitor and the second variable capacitor are connected in parallel to the input and output poles of the oscillator; A temperature monitoring module, used to monitor the operating temperature of the real-time clock chip and transmit a control voltage positively correlated with the operating temperature to the frequency adjustment module; The frequency adjustment module is used to compare the control voltage with a reference voltage and enable a corresponding variable capacitor according to the comparison result.

2. The real-time clock chip according to claim 1, characterized in that: The frequency adjustment module is further configured to enable the first variable capacitor if the control voltage is greater than the reference voltage; and enable the second variable capacitor if the control voltage is less than or equal to the reference voltage.

3. The real-time clock chip according to claim 1 or 2, characterized in that: The negative voltage correlation means that the capacitance value of the first variable capacitor increases with the increase of the control voltage, and the positive voltage correlation means that the capacitance value of the second variable capacitor decreases with the increase of the control voltage.

4. The real-time clock chip according to claim 1 or 2, characterized in that: The frequency adjustment module includes a comparator, a first switch connected in series with the first variable capacitor, and a second switch connected in series with the second variable capacitor; The first input end of the comparator is connected to a reference voltage, and the second input end is connected to the output end of the temperature monitoring module; the output end of the comparator is connected to the control input end of the first switch and the control input end of the second switch; the output end of the temperature monitoring module serves as the control voltage of the first variable capacitor and the second variable capacitor, and is respectively connected to the control input end of the first variable capacitor and the control input end of the second variable capacitor.

5. The real-time clock chip according to claim 1 or 2, characterized in that: The oscillator includes a dynamic capacitor, a dynamic inductor, and a dynamic resistor connected in series, and a static capacitor connected in parallel with the dynamic capacitor, the dynamic inductor, and the dynamic resistor.

6. A temperature compensation method for a real-time clock chip, characterized in that: The method is implemented based on the real-time clock chip described in any one of claims 1 to 5; the method comprises: Monitoring the operating temperature of the real-time clock chip and determining a control voltage positively correlated with the operating temperature; If the control voltage is greater than the reference voltage, the first variable capacitor is enabled; if the control voltage is less than or equal to the reference voltage, the second variable capacitor is enabled.

7. A temperature compensation device for a real-time clock chip, characterized in that: The device comprises: A control voltage determination module, used for monitoring the operating temperature of the real-time clock chip and determining a control voltage positively correlated with the operating temperature; The variable capacitor enabling module is used to enable the first variable capacitor if the control voltage is greater than the reference voltage; and to enable the second variable capacitor if the control voltage is less than or equal to the reference voltage.

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