CN116155238A - Relaxation oscillator system - Google Patents
Relaxation oscillator system Download PDFInfo
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- CN116155238A CN116155238A CN202310430109.8A CN202310430109A CN116155238A CN 116155238 A CN116155238 A CN 116155238A CN 202310430109 A CN202310430109 A CN 202310430109A CN 116155238 A CN116155238 A CN 116155238A
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- 230000010355 oscillation Effects 0.000 claims abstract description 170
- 239000003990 capacitor Substances 0.000 claims abstract description 101
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- 238000004364 calculation method Methods 0.000 claims description 12
- 238000010586 diagram Methods 0.000 description 10
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
- H03K3/01—Details
- H03K3/011—Modifications of generator to compensate for variations in physical values, e.g. voltage, temperature
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
- H03K3/01—Details
- H03K3/012—Modifications of generator to improve response time or to decrease power consumption
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
- H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
- H03K3/023—Generators characterised by the type of circuit or by the means used for producing pulses by the use of differential amplifiers or comparators, with internal or external positive feedback
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- 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
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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Abstract
The embodiment of the application relates to the technical field of integrated circuits and discloses a relaxation oscillator system. The relaxation oscillator system includes: the relaxation oscillation circuit comprises a comparator, a first capacitor connected with a negative input end of the comparator, a second capacitor connected with a positive input end of the comparator, an RC module respectively connected with the positive input end and the negative input end, and a switching module connected with an output end of the comparator, wherein the switching module is used for switching the relaxation oscillation circuit into a first mode or switching the relaxation oscillation circuit into a second mode according to a signal output by the output end, and in the first mode, the RC module is communicated with the positive input end, and the first capacitor is communicated with the negative input end; in the second mode, the RC module is conducted with the negative input terminal, and the second capacitor is conducted with the positive input terminal. The relaxation oscillator system provided by the embodiment of the application can provide a clock with stable frequency for the system, is easy to realize and has lower cost.
Description
Technical Field
Embodiments of the present disclosure relate to the field of integrated circuit technologies, and in particular, to a relaxation oscillator system.
Background
Current internet of things devices are mainly powered by a battery, and an important factor affecting the service life of the battery is the power consumption condition of the chip, so that the service life of the battery can be prolonged by reducing the power consumption of the chip. The chip of the Internet of things is in a sleep mode most of the time, and a timing clock is provided for the system only through the low-frequency oscillator in the sleep mode, so that the oscillating circuit with high frequency precision and low power consumption can maximally prolong the sleep time of the chip, and the power consumption of the chip is reduced.
A clock circuit based on a crystal oscillator can meet the above-described oscillating circuit requirements, but such a clock circuit has a disadvantage in that additional peripheral devices and chip pins are required, increasing hardware costs. Thus, a low cost RC relaxation oscillator on chip can be used instead of a crystal oscillator, as shown in fig. 1, but the comparator in the relaxation oscillator shown in fig. 1 is affected by the bias voltage in the circuit, resulting in poorer frequency stability of the relaxation oscillator compared to the crystal oscillator, requiring the use of a more complex bias voltage cancellation circuit for improving the frequency stability, being difficult to realize and having higher cost.
Disclosure of Invention
An object of an embodiment of the present application is to provide a relaxation oscillator system, which can provide a clock with a stable frequency for the system, and is easy to implement and low in cost.
To solve the above technical problems, embodiments of the present application provide a relaxation oscillator system, including a relaxation oscillation circuit, where the relaxation oscillation circuit includes a comparator, a first capacitor connected to a negative input end of the comparator, a second capacitor connected to a positive input end of the comparator, an RC module connected to the positive input end and the negative input end respectively, and a switching module connected to an output end of the comparator; the switching module is used for switching the relaxation oscillation circuit into a first mode or switching the relaxation oscillation circuit into a second mode according to the signal output by the output end; in the first mode, the RC module is conducted with the positive input end, the first capacitor is conducted with the negative input end, the RC module is used for receiving a supply current input by the second input end of the relaxation oscillation circuit so as to generate a standard voltage input to the comparator, and the first capacitor is used for receiving the supply current input by the first input end of the relaxation oscillation circuit so as to generate a first voltage which is input to the comparator and is equal to the standard voltage; in the second mode, the RC module is in conduction with the negative input end, the second capacitor is in conduction with the positive input end, the RC module is configured to receive a supply current input by the first input end to generate a standard voltage input to the comparator, and the second capacitor is configured to receive the supply current input by the second input end to generate a second voltage input to the comparator and equal to the standard voltage.
According to the relaxation oscillator system, the relaxation oscillation circuit is switched into the first mode or is switched into the second mode according to the signal output by the output end of the comparator by the switching module in the relaxation oscillation circuit, the RC module is conducted with the positive input end of the comparator in the first mode, the first capacitor is conducted with the negative input end of the comparator, so that the RC module receives the supply current input by the second input end of the relaxation oscillation circuit to generate the standard voltage input to the comparator, the first capacitor receives the supply current input by the first input end of the relaxation oscillation circuit to generate the first voltage equal to the standard voltage input to the comparator, the RC module is conducted with the negative input end in the second mode, the second capacitor is conducted with the positive input end, the RC module receives the supply current input by the first input end to generate the standard voltage input to the comparator, the RC module receives the supply current input by the second input end to the comparator, namely the RC module can store the supply current input by the second input end to the second input end of the comparator to generate the standard voltage, and the RC module can be connected with the positive input end of the comparator in the second mode to generate the second voltage to the second voltage, the bias voltage is not influenced by the bias voltage, and the bias device is not influenced by the voltage is easy to realize the comparison, and the bias voltage is not influenced by the voltage is easy to realize the comparison with the positive voltage of the comparator.
In addition, the relaxation oscillation circuit further comprises a first switch connected with the RC module and the positive input end, a second switch connected with the RC module and the negative input end, a third switch connected with the first capacitor and the negative input end, and a fourth switch connected with the second capacitor and the positive input end; the switching of the relaxation oscillation circuit to the first mode is specifically: controlling the first switch and the third switch to be closed, and the second switch and the fourth switch to be opened so as to enable the RC module to be conducted with the positive input end and the first capacitor to be conducted with the negative input end; the switching of the relaxation oscillation circuit to the second mode is specifically: and controlling the second switch and the fourth switch to be closed, and controlling the first switch and the third switch to be opened so as to enable the RC module to be conducted with the negative input end and the second capacitor to be conducted with the positive input end. The first capacitor, the second capacitor, the RC module and the comparator are connected through different switches respectively, so that flexible conduction of the paths of the first capacitor, the second capacitor, the RC module and the comparator is realized.
In addition, the system also comprises a temperature sensor and a frequency calibration module, wherein the temperature sensor is connected with the relaxation oscillation circuit, and the temperature sensor is also connected with the frequency calibration module; the temperature sensor is used for receiving a clock signal output by the relaxation oscillation circuit to acquire the working temperature of the relaxation oscillation circuit and sending the working temperature to the frequency calibration module; the frequency calibration module is used for acquiring capacitance parameters corresponding to the working temperature according to the working temperature of the relaxation oscillation circuit, sending the capacitance parameters corresponding to the working temperature to the frequency calibration module and sending the capacitance parameters to the relaxation oscillation circuit so that the relaxation oscillation circuit can adjust the current capacitance parameters to the capacitance parameters corresponding to the current working temperature, wherein a plurality of capacitance parameters at a plurality of working temperatures are prestored in the temperature sensor. According to the relaxation oscillation circuit capacitance parameter adjusting method, the relaxation oscillation circuit capacitance parameter is adjusted through the temperature sensor and the frequency calibration module, so that the problem that clock frequency is unstable due to the fact that clock signals are delayed due to the influence of temperature is avoided.
In addition, the temperature sensor comprises a first ring oscillator, a second ring oscillator and a temperature calculation module, wherein the temperature calculation module is respectively connected with the first ring oscillator and the second ring oscillator; the first ring oscillator is used for generating a first standard clock signal and sending the first standard clock signal to the temperature calculation module; the second ring oscillator is used for generating a second standard clock signal and sending the second standard clock signal to the temperature calculation module; the temperature calculation module is used for calculating the working temperature of the relaxation oscillation circuit according to the first standard clock signal and the second standard clock signal so as to improve the accuracy of the acquired temperature.
In addition, the temperature sensor is further used for sending a clock signal of the output of the relaxation oscillation circuit to the signal calibration module; the frequency calibration module is further configured to determine whether to adjust a current capacitance parameter of the relaxation oscillation circuit according to an output clock signal of the relaxation oscillation circuit and a preset third standard clock signal when a capacitance parameter corresponding to the working temperature is not obtained according to the working temperature of the relaxation oscillation circuit, and if the current capacitance parameter of the relaxation oscillation circuit is determined to be adjusted, obtain a target capacitance parameter of the relaxation oscillation circuit and send the target capacitance parameter to the relaxation oscillation circuit, so that the relaxation oscillation circuit adjusts the current capacitance parameter to the target capacitance parameter to comprehensively avoid an influence of temperature on clock frequency stability.
In addition, the frequency calibration module is further configured to compare the output clock signal of the relaxation oscillation circuit with the third standard clock signal, obtain a frequency deviation value between the output clock signal of the relaxation oscillation circuit and the third standard clock signal according to a preset software algorithm when the output clock signal of the relaxation oscillation circuit is unequal to the third standard clock signal, and determine a target capacitance parameter of the relaxation oscillation circuit according to the frequency deviation value, so as to improve accuracy of the determined target capacitance parameter.
In addition, the relaxation oscillation circuit comprises a capacitor array formed by a plurality of third capacitors and a fourth capacitor; the frequency calibration module is further configured to obtain a first target capacitance parameter of each third capacitor and a second target capacitance parameter of the fourth capacitor in the relaxation oscillation circuit, and send each first target capacitance parameter and each second target capacitance parameter to the relaxation oscillation circuit, so that the relaxation oscillation circuit can respectively adjust current capacitance parameters of a plurality of third capacitors to corresponding first target capacitance parameters, and adjust current capacitance parameters of the fourth capacitors to corresponding second target capacitance parameters. According to the clock delay calibration method, the clock delay is further calibrated by respectively adjusting the capacitance parameters of the third capacitor and the fourth capacitor, and the stability of the clock frequency is improved.
The fourth capacitor is periodically turned on or off to achieve accurate adjustment of the relaxation oscillation circuit capacitance parameters.
In addition, the system also comprises a counting module which is respectively connected with the relaxation oscillation circuit and the temperature sensor; the counting module is used for receiving a clock signal output by the relaxation oscillation circuit and periodically triggering the temperature sensor according to the clock signal so that the temperature sensor periodically acquires the working temperature of the relaxation oscillation circuit. According to the relaxation oscillation circuit, the working temperature of the relaxation oscillation circuit is obtained through the periodic trigger temperature sensor, so that the power consumption of the system is reduced.
In addition, the system also comprises a high-frequency crystal oscillator, wherein the high-frequency crystal oscillator is connected with the frequency calibration module; the high-frequency crystal oscillator is used for generating the second standard clock signal and sending the second standard clock signal to the frequency calibration module so that the frequency calibration module can determine whether to adjust the current capacitance parameter of the relaxation oscillation circuit according to the clock signal output by the relaxation oscillation circuit and the second standard clock signal. The second standard clock signal is generated through the high-frequency crystal oscillator, and the implementation mode is more universal.
Drawings
One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which the figures of the drawings are not to be taken in a limiting sense, unless otherwise indicated.
FIG. 1 is a schematic diagram of a relaxation oscillator;
FIG. 2 is a schematic diagram of a relaxation oscillator provided according to one embodiment of the present application;
FIG. 3 is a schematic diagram II of a relaxation oscillator provided in accordance with an embodiment of the present application;
FIG. 4 is a schematic diagram III of a relaxation oscillator provided in accordance with an embodiment of the present application;
FIG. 5 is a schematic diagram of a relaxation oscillator provided in accordance with an embodiment of the present application;
FIG. 6 is a schematic diagram of a relaxation oscillator provided in accordance with an embodiment of the present application;
FIG. 7 is a schematic diagram of a temperature sensor provided according to one embodiment of the present application;
FIG. 8 is a schematic diagram of a relaxation oscillator provided in accordance with an embodiment of the present application;
FIG. 9 is a schematic diagram of a capacitor array according to one embodiment of the present application;
fig. 10 is a schematic diagram of a relaxation oscillator according to an embodiment of the present application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, as will be appreciated by those of ordinary skill in the art, in the various embodiments of the present application, numerous technical details have been set forth in order to provide a better understanding of the present application. However, the technical solutions claimed in the present application can be implemented without these technical details and with various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not be construed as limiting the specific implementation of the present application, and the embodiments may be mutually combined and referred to without contradiction.
For ease of understanding, the relaxation oscillator will now be described as follows: factors that affect the clock frequency stability of the relaxation oscillator include the temperature of the resistor, and the bias voltage of the comparator. Regarding the temperature of the resistor, the temperature consistency can be better achieved through positive and negative temperature coefficient compensation, so that the influence of the temperature of the resistor on the stability of the clock frequency is eliminated; with respect to the bias voltage of the comparator, a relatively complex bias voltage cancellation circuit is required to cancel the bias voltage so that the relaxation oscillator generates a clock signal with stable frequency, but the bias voltage cancellation circuit is not easy to implement and has high cost.
The relaxation oscillator system can provide a clock with stable frequency for the system, and is easy to realize and low in cost.
An embodiment of the present application relates to a relaxation oscillator system, and implementation details of the relaxation oscillator system of the present embodiment are specifically described below, which are provided for understanding only and are not necessary to implement the present embodiment.
The structure of the relaxation oscillator system of this embodiment may be as shown in fig. 2, and specifically includes: relaxation oscillation circuit 20, wherein relaxation oscillation circuit 20 includes comparator 200, first electric capacity 201 connected with the negative input of comparator 200, second electric capacity 202 connected with the positive input of comparator 200, RC module 203 connected with positive input and negative input of comparator 200 respectively, and switch module 204 connected with the output of comparator 200.
The switching module 204 is configured to switch the relaxation oscillation circuit 20 to the first mode or switch the relaxation oscillation circuit 20 to the second mode according to the signal output from the output terminal of the comparator 200. In the first mode, the RC module 203 is in conduction with the positive input terminal of the comparator 200, and the first capacitor 201 is in conduction with the negative input terminal of the comparator 200, so that the RC module 203 can receive the supply current input to the second input terminal of the relaxation oscillation circuit 20 to generate the standard voltage input to the comparator 200 in the first mode, and simultaneously the first capacitor 201 can receive the supply current input to the first input terminal of the relaxation oscillation circuit 20 to generate the first voltage equal to the standard voltage input to the comparator 200 in the first mode. In the second mode, the RC module 203 is in conduction with the negative input terminal of the comparator 200, and the second capacitor 202 is in conduction with the positive input terminal of the comparator 200, so that the RC module 203 can receive the supply current input to the first input terminal of the relaxation oscillation circuit 20 to generate the standard voltage input to the comparator 200 in the second mode, and simultaneously the second capacitor 202 can receive the supply current input to the second input terminal of the relaxation oscillation circuit 20 to generate the second voltage equal to the standard voltage input to the comparator 200 in the second mode.
In a specific implementation, the supply currents of the first input terminal and the second input terminal are equal, and the RC module 203 is formed by a fixed resistor R and a capacitor C, where the number of R and C is not limited, so if the supply currents of the first input terminal and the second input terminal are equal, and the values of R and C of the RC module are fixed, the standard voltage generated by the RC module is fixed. The relaxation oscillation circuit 20 is alternately switched between the first mode and the second mode, and assuming that the switching module 204 firstly switches the relaxation oscillation circuit 20 into the first mode, that is, the RC module 203 is conducted with the positive input terminal of the comparator 200 and the first capacitor 201 is conducted with the negative input terminal of the comparator 200, after the RC module 203 generates the standard voltage, the voltage of the first capacitor 201 gradually increases until the standard voltage is increased to be equal to the standard voltage, the standard voltage generated by the RC module 203 and the first voltage generated by the first capacitor 201 are input into the comparator 200, and the switching module 204 can determine the input condition of the positive input terminal and the negative input terminal of the comparator 200 according to the signal output by the output terminal of the comparator 200, that is, determine whether the voltage of the first capacitor 201 increases to be equal to the standard voltage. After the first capacitor 201 is increased to the first voltage, the switching module 204 switches the relaxation oscillation circuit 20 to the second mode, that is, the RC module 203 is turned on with the negative input terminal of the comparator 200, and the second capacitor 202 is turned on with the positive input terminal of the comparator 200, after the RC module 203 generates the standard voltage, the voltage of the second capacitor 202 is gradually increased until the standard voltage is increased to the second voltage equal to the standard voltage, the standard voltage generated by the RC module 203 and the second voltage generated by the second capacitor 202 are input into the comparator 200, and the switching module 204 can determine the input condition of the positive input terminal and the negative input terminal of the comparator 200 according to the signal output by the output terminal of the comparator 200, that is, determine whether the voltage of the second capacitor 202 is increased to the second voltage equal to the standard voltage. After the second capacitor 202 increases to the second voltage, the switching module 204 switches the relaxation oscillation circuit 20 to the first mode again, and so on, that is, the two modes of the relaxation oscillation circuit 20 are performed for one cycle.
In one example, relaxation oscillation circuit 20 further includes a first switch connecting RC module 203 with the positive input of comparator 200, a second switch connecting RC module 203 with the negative input of comparator 200, a third switch connecting first capacitor 201 with the negative input of comparator 200, and a fourth switch connecting second capacitor 202 with the positive input of comparator 200. Wherein the relaxation oscillation circuit 20 is switched to the first mode, specifically: controlling the first switch and the third switch to be closed, and the second switch and the fourth switch to be opened so as to enable the RC module 203 to be conducted with the positive input end of the comparator 200 and the first capacitor 201 to be conducted with the negative input end of the comparator 200; the relaxation oscillation circuit 20 is switched to the second mode, specifically: the second switch and the fourth switch are controlled to be closed, and the first switch and the third switch are controlled to be opened, so that the RC module 203 is conducted with the negative input terminal of the comparator 200, and the second capacitor 202 is conducted with the positive input terminal of the comparator 200.
For ease of understanding, reference may be made to the relaxation oscillation circuit shown in fig. 3, where IO1 is a first input terminal, IO2 is a second input terminal, the RC module 203 includes resistors R and C, S1 is a first switch, SN1 is a second switch, SN2 is a third switch, S2 is a fourth switch, and the switching module 204 includes an S switch that can control S1 and S2, and an SN switch that can control SN1 and SN 2. Thus, the relaxation oscillation circuit in the first mode may be as shown in fig. 4, wherein SN1 and SN2 are closed such that the RC module 203 is conductive with the positive input of the comparator 200 and the first capacitor 201 is conductive with the negative input of the comparator 200; the relaxation oscillation circuit in the second mode may be as shown in fig. 5, wherein S1 and S2 are closed, such that the RC module 203 is conductive with the negative input of the comparator 200 and the second capacitor 202 is conductive with the positive input of the comparator 200. In this embodiment, different switches are disposed between the positive and negative input ends of the first capacitor 201, the second capacitor 202, the RC module 203 and the comparator 200, so that flexible conduction between the first capacitor 201, the second capacitor 202, and the RC module 203 and the comparator 200 can be realized.
In this embodiment, the relaxation oscillation circuit is switched to a first mode or the relaxation oscillation circuit is switched to a second mode according to a signal output by an output end of the comparator by a switching module in the relaxation oscillation circuit, in the first mode, the RC module is conducted with a positive input end of the comparator, the first capacitor is conducted with a negative input end of the comparator, so that the RC module receives a supply current input by a second input end of the relaxation oscillation circuit to generate a standard voltage input to the comparator, and the first capacitor receives a supply current input by the first input end of the relaxation oscillation circuit to generate a first voltage equal to the standard voltage input to the comparator, in the second mode, the RC module is conducted with the negative input end, the second capacitor is conducted with the positive input end, so that the RC module receives the supply current input by the first input end, the RC module can store the standard voltage, the relaxation oscillation circuit alternately charges and discharges the first capacitor and the second capacitor, so that the RC module is alternately connected with the positive input end and the negative input end of the comparator in the process of generating a clock signal, the input voltages of the positive input end and the negative input end of the comparator are equal, no bias voltage exists, the problem that the frequency of the clock signal output by the relaxation oscillation circuit is unstable due to the existence of the bias voltage of the comparator is avoided, the implementation mode is simple, expensive electronic devices are not needed, and the cost is low.
Another embodiment of the present application relates to a relaxation oscillator system, and implementation details of the relaxation oscillator system of this embodiment are specifically described below, which are provided for ease of understanding only and are not necessary to implement this embodiment.
The structure of the relaxation oscillator system of this embodiment may be as shown in fig. 6, and specifically includes: the temperature sensor comprises a relaxation oscillation circuit 60, a temperature sensor 61 and a frequency calibration module 62, wherein the relaxation oscillation circuit 60 is connected with the temperature sensor 61, and the temperature sensor 61 is connected with the frequency calibration module 62. The relaxation oscillation circuit 60 is similar to the relaxation oscillation circuit 20 in the above embodiment, and will not be described here again.
The temperature sensor 61 is configured to receive a clock signal output by the relaxation oscillation circuit 60, to obtain an operating temperature of the relaxation oscillation circuit, and send the operating temperature to the frequency calibration module 62. The frequency calibration module 62 is configured to obtain a capacitance parameter corresponding to an operating temperature according to the operating temperature of the relaxation oscillation circuit, and send the capacitance parameter corresponding to the current operating temperature to the relaxation oscillation circuit 60, so that the relaxation oscillation circuit 60 adjusts the current capacitance parameter to the capacitance parameter corresponding to the current operating temperature. Since factors affecting the frequency stability of the relaxation oscillation circuit also include the delay of the comparator, the delay of the comparator needs to be calibrated, in particular by adjusting the capacitance parameter of the relaxation oscillation circuit 60, in particular the value of C in the RC module 203. Therefore, in this embodiment, the temperature sensor and the frequency calibration module are used to adjust the capacitance parameter of the relaxation oscillation circuit, so as to avoid the problem that the clock signal is delayed due to the influence of temperature, and the clock frequency is unstable.
In one example, the temperature sensor 61 is periodically turned on or off, i.e., periodically acquires the operating temperature of the relaxation oscillation circuit 60, to further reduce the power consumption of the system.
In some embodiments, the structure of the temperature sensor 61 may be as shown in fig. 7, and specifically includes: the first ring oscillator 610, the second ring oscillator 611 and the temperature calculation module 612, the temperature calculation module 612 is connected to the first ring oscillator 610 and the second ring oscillator 611, respectively.
The first ring oscillator is configured to generate a first standard clock signal and send the first standard clock signal to the temperature calculating module 612, the second ring oscillator 611 is configured to generate a second standard clock signal and send the second standard clock signal to the temperature calculating module 612, and the temperature calculating module 612 is configured to calculate an operating temperature of the relaxation oscillation circuit 60 according to the first standard clock signal and the second standard clock signal. The frequency of the first standard clock signal does not change with the temperature change, and the frequency of the second standard clock signal changes with the temperature change, so that the temperature sensor 61 inputs the first standard clock signal and the second standard clock signal into the same module, that is, the temperature calculating module 612, and the temperature calculating module 612 can obtain the current working temperature of the relaxation oscillation circuit 60 based on the count difference of the first standard clock signal and the second standard clock signal in the same time, and the accuracy of the temperature value obtained by this calculating method is higher.
In some embodiments, the temperature sensor 61 further sends the clock signal output by the relaxation oscillation circuit 60 to the frequency calibration module 62 after receiving the clock signal output by the relaxation oscillation circuit 60, and the frequency calibration module 62 is further configured to determine whether to adjust the current capacitance parameter of the relaxation oscillation circuit 60 according to the clock signal output by the relaxation oscillation circuit 60 and a preset second standard clock signal if the capacitance parameter corresponding to the operation temperature is not obtained according to the operation temperature of the relaxation oscillation circuit, and if it is determined to adjust the current capacitance parameter of the relaxation oscillation circuit 60, obtain the target capacitance parameter of the relaxation oscillation circuit 60 and send the target capacitance parameter to the relaxation oscillation circuit 60 for the relaxation oscillation circuit 60 to adjust the current capacitance parameter to the target capacitance parameter. The second preset standard clock signal is a clock signal with standard and stable frequency.
In some embodiments, the relaxation oscillator system may further comprise a high frequency crystal oscillator 63 as shown in fig. 8, the high frequency crystal oscillator 63 being connected to the frequency calibration module 62. The high-frequency crystal oscillator is configured to generate a third standard clock signal, and send the third standard clock signal to the frequency calibration module 62, so that the frequency calibration module 62 determines whether to adjust the current capacitance parameter of the relaxation oscillation circuit 60 according to the clock signal output by the relaxation oscillation circuit 60 and the third standard clock signal. In the embodiment, the third standard clock signal is generated by the high-frequency crystal oscillator, so that the implementation mode is simpler.
In one example, the frequency calibration module 62 is specifically configured to compare the output clock signal of the relaxation oscillation circuit 60 with the third standard clock signal, obtain, according to a preset software algorithm, a frequency deviation value between the output clock signal of the relaxation oscillation circuit 60 and the third standard clock signal when the output clock signal of the relaxation oscillation circuit 60 is not equal to the third standard clock signal, determine a target capacitance parameter of the relaxation oscillation circuit 60 according to the frequency deviation value, and the determined target capacitance parameter is an optimal target capacitance parameter.
In some embodiments, the RC module 203 of the relaxation oscillation circuit 60 specifically includes a capacitor array including a plurality of third capacitors and a fourth capacitor, and the frequency calibration module 62 is further configured to obtain a first target capacitance parameter of each third capacitor and a second target capacitance parameter of each fourth capacitor in the relaxation oscillation circuit 60, and send each first target capacitance parameter and each second target capacitance parameter to the relaxation oscillation circuit 60, so that the relaxation oscillation circuit 60 adjusts the current capacitance parameters of the plurality of third capacitors to corresponding first target capacitance parameters, and adjusts the current capacitance parameters of the fourth capacitors to second target capacitance parameters. The fourth capacitor is periodically turned on or off to further realize accurate adjustment of the capacitance parameter. In this embodiment, the capacitance parameters of the third capacitor and the fourth capacitor are respectively adjusted to further calibrate the clock delay, so as to improve the stability of the frequency all the time.
It can be understood that the RC module 203 of the relaxation oscillation circuit 60 may also include only a capacitor array formed by a plurality of third capacitors, and the frequency calibration module 62 only needs to acquire the first target capacitance parameters of each third capacitor in the relaxation oscillation circuit 60 and send each first target capacitance parameter to the relaxation oscillation circuit 60, so that the relaxation oscillation circuit 60 adjusts the current capacitance parameters of the plurality of third capacitors to corresponding first target capacitance parameters.
In one example, the capacitor array is shown in fig. 9, and specifically includes N third capacitors C1 (only 7 capacitors are shown in fig. 9) and one fourth capacitor C2, where each of the third capacitors C1 and the fourth capacitor C2 corresponds to a switch. The switch of the fourth capacitor C2 is periodically turned on or turned off, and the period length can be set by a person skilled in the art according to actual needs, so that the period size of the relaxation oscillation circuit 60 can be further adjusted by adjusting the size of the switch period of the fourth capacitor C2, so as to realize clock calibration of the relaxation oscillation circuit 60 and improve the stability of clock frequency.
In some embodiments, the relaxation oscillator system may further comprise a counting module 64 as shown in fig. 10, the counting module 64 being connected to the relaxation oscillation circuit 60 and the temperature sensor 61, respectively. The counting module 64 is configured to receive the clock signal output by the relaxation oscillation circuit 60, and periodically trigger the temperature sensor according to the clock signal, so that the temperature sensor periodically obtains the operating temperature of the relaxation oscillation circuit 60. In this embodiment, the working temperature of the relaxation oscillation circuit is obtained by periodically triggering the temperature sensor, so as to reduce the power consumption of the system.
It should be noted that, the foregoing examples in the present embodiment are all examples for understanding and are not limited to the technical solution of the present invention.
In one embodiment, the specific procedure for calibrating the comparator delay for the relaxation oscillation system is as follows, including:
s1, a temperature sensor receives a clock signal output by a relaxation oscillation circuit, and the working temperature of the relaxation oscillation circuit is obtained according to the clock signal.
S2, the temperature sensor sends the working temperature of the relaxation oscillation circuit and a clock signal output by the relaxation oscillation circuit to the frequency calibration module.
S3, the frequency calibration module acquires capacitance parameters corresponding to the working temperature according to the working temperature of the relaxation oscillation circuit. And determining whether to adjust the current capacitance parameter of the relaxation oscillation circuit according to the capacitance parameter corresponding to the working temperature, and if so, sending the capacitance parameter corresponding to the current working temperature to the relaxation oscillation circuit so that the relaxation oscillation circuit can adjust the current capacitance parameter to the capacitance parameter corresponding to the current working temperature.
If the frequency calibration module does not acquire the capacitance parameter corresponding to the working temperature, the frequency calibration module is further configured to determine whether to adjust the current capacitance parameter of the relaxation oscillation circuit according to the output clock signal of the relaxation oscillation circuit and a preset second standard clock signal, and if the current capacitance parameter of the relaxation oscillation circuit is determined to be adjusted, acquire the target capacitance parameter of the relaxation oscillation circuit and send the target capacitance parameter to the relaxation oscillation circuit so that the relaxation oscillation circuit can adjust the current capacitance parameter to the target capacitance parameter.
S4, closing the temperature sensor.
The above steps of the methods are divided, for clarity of description, and may be combined into one step or split into multiple steps when implemented, so long as they include the same logic relationship, and they are all within the protection scope of this patent; it is within the scope of this patent to add insignificant modifications to the algorithm or flow or introduce insignificant designs, but not to alter the core design of its algorithm and flow.
It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of implementing the present application and that various changes in form and details may be made therein without departing from the spirit and scope of the embodiments herein. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the embodiments herein, and the scope of the embodiments herein should be assessed accordingly.
Claims (10)
1. A relaxation oscillator system, comprising: the relaxation oscillation circuit comprises a comparator, a first capacitor connected with a negative input end of the comparator, a second capacitor connected with a positive input end of the comparator, an RC module respectively connected with the positive input end and the negative input end, and a switching module connected with an output end of the comparator;
the switching module is used for switching the relaxation oscillation circuit into a first mode or switching the relaxation oscillation circuit into a second mode according to the signal output by the output end;
in the first mode, the RC module is conducted with the positive input end, the first capacitor is conducted with the negative input end, the RC module is used for receiving a supply current input by the second input end of the relaxation oscillation circuit so as to generate a standard voltage input to the comparator, and the first capacitor is used for receiving the supply current input by the first input end of the relaxation oscillation circuit so as to generate a first voltage which is input to the comparator and is equal to the standard voltage;
in the second mode, the RC module is in conduction with the negative input end, the second capacitor is in conduction with the positive input end, the RC module is configured to receive a supply current input by the first input end to generate a standard voltage input to the comparator, and the second capacitor is configured to receive the supply current input by the second input end to generate a second voltage input to the comparator and equal to the standard voltage.
2. The relaxation oscillator system of claim 1, wherein said relaxation oscillation circuit further comprises a first switch connecting said RC module to said positive input, a second switch connecting said RC module to said negative input, a third switch connecting said first capacitor to said negative input, and a fourth switch connecting said second capacitor to said positive input;
the switching of the relaxation oscillation circuit to the first mode is specifically: controlling the first switch and the third switch to be closed, and the second switch and the fourth switch to be opened so as to enable the RC module to be conducted with the positive input end and the first capacitor to be conducted with the negative input end;
the switching of the relaxation oscillation circuit to the second mode is specifically: and controlling the second switch and the fourth switch to be closed, and controlling the first switch and the third switch to be opened so as to enable the RC module to be conducted with the negative input end and the second capacitor to be conducted with the positive input end.
3. The relaxation oscillator system of claim 1, further comprising a temperature sensor and a frequency calibration module, said temperature sensor being connected to said relaxation oscillation circuit, said temperature sensor being further connected to said frequency calibration module;
the temperature sensor is used for receiving a clock signal output by the relaxation oscillation circuit to acquire the working temperature of the relaxation oscillation circuit and sending the working temperature to the frequency calibration module;
the frequency calibration module is used for acquiring capacitance parameters corresponding to the working temperature according to the working temperature of the relaxation oscillation circuit, and sending the capacitance parameters corresponding to the working temperature to the relaxation oscillation circuit so that the relaxation oscillation circuit can adjust the current capacitance parameters to the capacitance parameters corresponding to the working temperature, wherein the frequency calibration module stores a plurality of capacitance parameters at a plurality of working temperatures.
4. The relaxation oscillator system of claim 3, wherein said temperature sensor comprises a first ring oscillator, a second ring oscillator, and a temperature calculation module, said temperature calculation module being connected to said first ring oscillator and said second ring oscillator, respectively;
the first ring oscillator is used for generating a first standard clock signal and sending the first standard clock signal to the temperature calculation module;
the second ring oscillator is used for generating a second standard clock signal and sending the second standard clock signal to the temperature calculation module;
the temperature calculation module is used for calculating the working temperature of the relaxation oscillation circuit according to the first standard clock signal and the second standard clock signal.
5. The relaxation oscillator system of claim 4, wherein said temperature sensor is further configured to send a clock signal of an output of said relaxation oscillation circuit to said frequency calibration module;
the frequency calibration module is further configured to determine whether to adjust a current capacitance parameter of the relaxation oscillation circuit according to an output clock signal of the relaxation oscillation circuit and a preset third standard clock signal when a capacitance parameter corresponding to the operating temperature is not obtained according to the operating temperature of the relaxation oscillation circuit, and if the current capacitance parameter of the relaxation oscillation circuit is determined to be adjusted, obtain a target capacitance parameter of the relaxation oscillation circuit, and send the target capacitance parameter to the relaxation oscillation circuit so that the relaxation oscillation circuit can adjust the current capacitance parameter to the target capacitance parameter.
6. The relaxation oscillator system of claim 5, wherein said frequency calibration module is further configured to compare an output clock signal of said relaxation oscillation circuit with said third standard clock signal, obtain a frequency deviation value between an output clock signal of said relaxation oscillation circuit and said third standard clock signal according to a preset software algorithm if said output clock signal of said relaxation oscillation circuit is not equal to said third standard clock signal, and determine a target capacitance parameter of said relaxation oscillation circuit according to said frequency deviation value.
7. The relaxation oscillator system of claim 6, wherein said relaxation oscillation circuit comprises a capacitor array comprising a plurality of third capacitors and a fourth capacitor;
the frequency calibration module is further configured to obtain a first target capacitance parameter of each third capacitor and a second target capacitance parameter of the fourth capacitor in the relaxation oscillation circuit, and send each first target capacitance parameter and each second target capacitance parameter to the relaxation oscillation circuit, so that the relaxation oscillation circuit can respectively adjust current capacitance parameters of a plurality of third capacitors to corresponding first target capacitance parameters, and adjust current capacitance parameters of the fourth capacitors to corresponding second target capacitance parameters.
8. The relaxation oscillator system of claim 7, wherein said fourth capacitance is periodically turned on or off.
9. The relaxation oscillator system of claim 3, further comprising a counting module connected to said relaxation oscillation circuit and said temperature sensor, respectively;
the counting module is used for receiving a clock signal output by the relaxation oscillation circuit and periodically triggering the temperature sensor according to the clock signal so that the temperature sensor periodically acquires the working temperature of the relaxation oscillation circuit.
10. The relaxation oscillator system of claim 5, further comprising a high frequency crystal oscillator, said high frequency crystal oscillator being connected to said frequency calibration module;
the high-frequency crystal oscillator is used for generating the second standard clock signal and sending the second standard clock signal to the frequency calibration module so that the frequency calibration module can determine whether to adjust the current capacitance parameter of the relaxation oscillation circuit according to the clock signal output by the relaxation oscillation circuit and the second standard clock signal.
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| CN202310430109.8A CN116155238A (en) | 2023-04-21 | 2023-04-21 | Relaxation oscillator system |
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