CN114531150A - Double-frequency output method and device for small-size chip and small-size chip - Google Patents

Abstract

The embodiment of the invention discloses a double-frequency output method and device suitable for a small-size chip and the small-size chip, relates to the technical field of integrated circuit chips and communication equipment, and can further reduce the size and cost of the overall scheme, so that the requirement of two-stage frequency output independent switch control can be met on the premise of realizing high integration. The invention includes: the small-size chip adopts a single MHz-stage crystal oscillator as an oscillation source, the MHz-stage crystal oscillator is simultaneously connected with a MHz-stage clock driver and a kHz-stage frequency divider, wherein the MHz-stage clock driver is used for controlling the on-off state of MHz-stage frequency output, and the kHz-stage clock driver is used for controlling the on-off state of kHz-stage frequency output; and after the current required frequency output is confirmed, respectively controlling the switching state of the MHz level frequency output and the switching state of the kHz level frequency output by the MHz level clock driver and the kHz level clock driver. The invention is suitable for small-size chips.

Description

Double-frequency output method and device for small-size chip and small-size chip

Technical Field

The invention relates to the technical field of communication equipment, in particular to a double-frequency output method and device suitable for a small-size chip and the small-size chip.

Background

In some communication systems such as LTE, 5G communication, GNNS, and internet of things intelligent terminals, besides the requirement of a service clock with a high-precision MHz-level frequency, a clock with a kHz level, such as a kHz level, is usually required to be used as a timing and low-speed machine clock of a main control unit in the entire system, so as to ensure that the system can be accurately operated for a long time in a standby or sleep mode. Generally, modern network communication products such as small intelligent terminals and 5G communication devices are generally required to have indexes such as miniaturization and low power consumption.

However, as devices are miniaturized, the size of the circuit board becomes smaller and smaller (the circuit board, chip, etc. applied to the miniaturized devices are also referred to as "small-sized chip" in the industry), and placing two independent crystal oscillators to generate clock signals will undoubtedly add extra space and cost to the circuit board design. In particular, in an actual production process, it is found that if the switching states are controlled independently, two independent crystal oscillators are required to output clock signals of different levels, signals interfere with each other, and an additional isolation circuit is required, so that a certain distance is usually considered in layout, and finally, the effect of reducing the size through design optimization is limited.

Therefore, although the package size of crystal oscillator clock chips has been miniaturized, there is a distance to fully meet the requirements of the devices, especially in terms of the reduction in size and cost of circuit board designs.

Disclosure of Invention

The embodiment of the invention provides a double-frequency output method and device suitable for a small-size chip and the small-size chip, which can further reduce the size and cost of the overall scheme, thereby meeting the requirement of two-stage frequency output independent switch control on the premise of realizing high integration.

In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:

in a first aspect, an embodiment of the present invention provides a method, including:

the small-size chip adopts a single MHz-level crystal oscillator as an oscillation source, the MHz-level crystal oscillator is simultaneously connected with a MHz-level clock driver and a kHz-level frequency divider, wherein the MHz-level clock driver is used for controlling the switching state of MHz-level frequency output, and the kHz-level clock driver is used for controlling the switching state of kHz-level frequency output; and after the currently required frequency output is confirmed, the switching state of the MHz-level frequency output and the switching state of the kHz-level frequency output are respectively controlled by the MHz-level clock driver and the kHz-level clock driver.

In a second aspect, an embodiment of the present invention provides a small-sized chip, including:

a MHz level crystal oscillator is installed in the small-sized chip as an oscillation source and generates a MHz level oscillation signal, and the components of the MHz level crystal oscillator include: a crystal resonator, an oscillation circuit and a load capacitor;

the MHz level crystal oscillator is connected with a MHz level clock driver and a kHz level frequency divider, and the kHz level frequency divider is connected with a kHz level clock driver.

After the MHz-level oscillation signal generated by the MHz-level crystal oscillator is input into the MHz-level clock driver, the MHz-level clock driver generates MHz-level frequency output; after MHz oscillating signals generated by the MHz crystal oscillator are input into the kHz level frequency divider, the kHz level frequency divider outputs oscillating signals converted into kHz level oscillating signals, and then the oscillating signals are input into the kHz level clock driver, and the kHz level clock driver generates kHz level frequency output.

The MHz-level clock driver is used for controlling the switching state of the MHz-level frequency output; the kHz level clock driver is used for controlling the switching state of the kHz level frequency output.

In a third aspect, an embodiment of the present invention provides a dual frequency output device for a small-sized chip, including:

the compensation triggering unit is used for triggering the temperature compensation module to operate when temperature compensation is needed, wherein the working mode of temperature compensation comprises the following steps: a high-precision compensation mode and a low-power consumption mode;

the high-precision compensation unit is used for detecting the temperature information of the crystal resonator in the MHz crystal oscillator through the temperature compensation module when entering the high-precision compensation mode; acquiring the frequency offset of the MHz crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the capacitance value of a load capacitor in the MHz crystal oscillator according to the frequency offset;

the low-power compensation unit is used for detecting the temperature information of the crystal resonator in the MHz crystal oscillator through the temperature compensation module when entering the low-power mode; and acquiring the frequency offset of the MHz-level crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the frequency dividing ratio of the kHz-level frequency divider according to the frequency offset.

According to the double-frequency output method and device suitable for the small-size chip and the small-size chip, the MHz frequency clock and the kHz frequency clock can be generated only by using the single MHz frequency crystal oscillator, namely, two-stage frequency output is realized by one crystal oscillator, and the two-stage frequency output can independently control a switch; under the scene that the frequency output needs temperature compensation, namely higher precision is required, the working conditions of high precision and low power consumption are considered simultaneously in multiple modes; in addition, in this embodiment, only a single MHz-level frequency crystal oscillator is used, a high-precision MHz-level frequency clock and a low-power consumption kHz-level frequency clock can be generated, that is, a working condition of both high precision and medium and high precision can be realized by one crystal oscillator, specifically, clocks with two levels of frequencies of the MHz-level frequency clock and the kHz-level frequency clock can be realized by one crystal oscillator, signals for the two levels of frequency clocks are substantially homologous, and there is no problem of mutual interference caused by different source signals in the prior art, so that the problem of mutual interference of two clock signals easily occurring on a small-sized chip is solved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 and 2 are schematic diagrams illustrating the oscillation principle of the TCXO;

FIG. 3 is a diagram of a conventional system architecture;

FIG. 4 is a schematic diagram of a basic chip structure according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a system design architecture according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a chip structure with a temperature compensation module according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention. As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

A TCXO (Temperature compensated X' tal) (crystal) Oscillator is a commonly used frequency device, and the principle thereof is to control the output frequency of the crystal Oscillator after properly transforming Temperature information by sensing the ambient Temperature so as to achieve the effect of stabilizing the output frequency. The TCXO is mainly used in electronic devices as a clock function module providing high precision and high stability, a common frequency is in the MHz level, and is commonly used in some communication systems such as LTE, 5G communication, GNNS, internet of things smart terminals, and the like. For example: the oscillation principle of the TCXO is that the piezoelectric effect of an on-chip quartz crystal resonator is utilized and matched with an on-chip oscillator circuit to generate a clock signal for calibrating the frequency. Equivalent circuits of the internal quartz crystal resonator are shown in fig. 1 and 2, in which Co is a static capacitor, L1 is a dynamic inductor, C1 is a dynamic capacitor, and R1 is a dynamic resistor. When in use, the quartz crystal resonator and an external circuit form an oscillating circuit, and the oscillating frequency of the quartz crystal resonator is related to the integral load capacitance.

The load capacitor is composed of a parasitic capacitor Cs at two ends of the crystal resonator, an input capacitor Ci, an output capacitor Co, a lead parasitic capacitor, a PCB lead parasitic capacitor, an external capacitor and the like. The load capacitance determines the accuracy of the frequency of the oscillating circuit, and if the load capacitance is smaller than the required value of the crystal resonator, the frequency is larger, and vice versa. In the TCXO temperature compensation crystal oscillator, a load capacitor and a start-oscillation circuit required by a crystal resonator are integrated into a chip, and the crystal oscillator can start oscillation to generate an accurate clock signal under the condition of adding power excitation.

In practical application scenarios, the output frequency of the crystal resonator varies with the ambient temperature, for example, within a temperature range of-40 to 85 ℃, the frequency offset range of the crystal resonator may reach a nominal frequency of +/-20 to 30ppm (parts per million), and if a high accuracy (e.g., within +/-1 ppm) is to be achieved, the correction of the compensation circuit is required. Note: the above numerical values are only auxiliary descriptions and are not actual indexes of the scheme.

The principle of TCXO frequency compensation is to control the output frequency of the crystal oscillator by sensing the ambient temperature and appropriately converting the temperature information to achieve the effect of stabilizing the output frequency. The common realization mode is to monitor the temperature in real time through a thermistor network in a chip, adjust the load capacitance of the crystal resonator based on the temperature information to correct the frequency error caused by the temperature, and compensate the original oscillation signal with medium precision to high precision.

The TCXO provides a high-precision and high-stability clock in the electronic device, the common frequency is in the MHz level, and the TCXO is commonly used in some communication systems such as LTE, 5G communication, GNNS, and smart terminals of internet of things. In addition to the requirement of high-precision MHz level Clock, in these systems, a kHz level Clock is usually required, typically, a 32.768kHz Clock signal is used as a Clock reference of an RTC (Real-Time Clock), i.e., a Real-Time Clock chip module, and is generally implemented by a crystal oscillator plus compensation mode, the Clock is used as a timing and low-speed machine Clock of a main control unit in the whole system, and the characteristics of the Clock are medium-high precision and low power consumption to ensure that the system can be accurately operated for a long Time in a standby or sleep mode.

For these two types of clock requirements of different frequency levels, the existing system generally uses two separate crystal oscillator clock chips. Such as the TCXO and RTC clock modes used in typical clock systems, as shown in fig. 3. In a normal working mode, the TCXO and the RTC clock are kept in a normally open state; in standby or sleep mode, the TCXO is typically turned off to save power, leaving the RTC clock to maintain the most basic operation of the system.

In view of the problems in the prior art, the present embodiment is further designed, and the general design purpose is as follows: by adopting an integrated scheme, a MHz-level crystal oscillator is used as an oscillation source (also called as a local oscillator) to simultaneously generate independently controllable MHz-level and kHz-level frequency outputs so as to reduce the size of a chip, and further meet the requirements of systems and equipment on circuit board size reduction and cost reduction, wherein the basic structure of the chip is roughly shown in FIG. 4. A MHz-level crystal oscillator with common temperature stability is installed in the small-size chip and serves as an oscillation source to generate MHz-level oscillation signals. The component parts of the crystal oscillator in the MHz level comprise: the device comprises a MHz-class crystal resonator, an oscillating circuit and a load capacitor. When the oscillation signal of the MHz level generated by the MHz level crystal oscillator is input into the MHz level clock driver, the MHz level clock driver generates MHz level frequency output. When the MHz level crystal oscillator generates MHz oscillation signal and inputs the MHz level crystal oscillator into the kHz level frequency divider, the kHz level frequency divider converts the MHz level oscillation signal into kHz level oscillation signal, and inputs the converted kHz level oscillation signal into the kHz level clock driver and generates kHz level frequency output.

As shown in fig. 5, the integrated solution can effectively reduce the board layout area of the chip to reduce the size and cost of the circuit board.

However, in practical applications, the system needs a high-precision clock signal in the normal operation mode and needs a low-power consumption clock signal in the standby mode. Therefore, the design difficulty of the scheme of the embodiment is as follows: how to use the same oscillation source to meet the requirements of different scenes.

The embodiment of the invention provides a double-frequency output method suitable for a small-size chip, as shown in fig. 6, comprising the following steps:

the small-size chip adopts a single MHz-level crystal oscillator as an oscillation source, the MHz-level crystal oscillator is simultaneously connected with a MHz-level clock driver, a kHz-level frequency divider and a driver to generate MHz-level and kHz-level two-level frequency output, wherein the MHz-level clock driver controls the switching state of the MHz-level frequency output, and the kHz-level clock driver controls the switching state of the kHz-level frequency output.

And after the currently required frequency output is confirmed, the switching state of the MHz-level frequency output and the switching state of the kHz-level frequency output are respectively controlled by the MHz-level clock driver and the kHz-level clock driver. In practical applications, a total of 4 switching states can occur: only MHz frequency output, only kHz frequency output, both MHz frequency output and kHz frequency output and no frequency output. Specifically, the "determination" action may be performed by a device running the chip designed in this embodiment as an execution subject, for example, a switch device equipped with a small-sized chip, and specifically, the determination and confirmation may be performed by a system program running on the device.

When temperature compensation is needed, the temperature compensation module is triggered to operate, wherein the working mode of the temperature compensation comprises the following steps: a high-precision compensation mode and a low-power consumption mode. The small-size chip adopts a temperature compensation module with double working modes, and under the scene that the frequency output needs temperature compensation, namely higher precision requirement, the temperature compensation module detects the temperature information in the small-size chip and respectively compensates two-stage frequency output according to the detected temperature information, namely precision is improved. In this embodiment, a MHz-level crystal oscillator is installed in the small-sized chip as an oscillation source, and the MHz-level crystal oscillator is connected to the MHz-level clock driver and the kHz-level frequency divider. Under the high-precision compensation mode, the load capacitance of the crystal oscillator is adjusted to achieve temperature compensation of frequency, so that the MHz and kHz frequency output can achieve high-precision stability. And after entering the low-power-consumption compensation mode, adjusting the compensation mode to modify the frequency dividing ratio of the kHz-level frequency divider so as to enable the frequency output of the kHz level to reach the stability of medium and high precision. In the embodiment, a compensation strategy can be formulated through the temperature compensation module according to the requirement of the working system, and the strategy is divided into a high-precision compensation mode and a low-power compensation mode. Wherein, the high-precision compensation work directly confirms how many capacitance values need to be compensated; and in the low power consumption compensation mode, the frequency division ratio needs to be confirmed.

Further, when the high-precision compensation mode is entered, the temperature information of the crystal resonator inside the MHz crystal oscillator is detected through the temperature compensation module. Acquiring the frequency offset of the MHz crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the capacitance value of a load capacitor in the MHz crystal oscillator according to the frequency offset, wherein the temperature characteristic of the resonator comprises the following steps: a varying relationship between a frequency of the resonator and a temperature of the resonator.

Wherein, according to the detected temperature information, modifying the capacitance value of the load capacitor comprises: detecting temperature information of the crystal oscillator through a temperature compensation module; and determining the frequency offset of the crystal oscillator according to the temperature information and the temperature characteristic of the resonator, and correspondingly modifying the capacitance value of the load capacitor according to the obtained frequency offset to perform frequency compensation on the crystal oscillator so as to improve the frequency accuracy of the frequency output of the MHz level and the kHz level. The source of the clock is a crystal oscillator which is a medium-precision clock source, and the crystal resonator, the load capacitor and the oscillation circuit are combined into the crystal oscillator, wherein the output frequency of the crystal oscillator can be influenced by the size of the load capacitor. It should be noted that the principle and mechanism of generating the oscillation signal by using the common effect of the crystal resonator, the oscillation circuit and the load capacitor belong to the existing technologies, and are not described in detail in this embodiment.

In practical applications, the frequency of the crystal oscillator is compensated to cope with the situation that the frequency varies with the temperature, such as: the frequency is 100MHz at 20 ℃ operating temperature and the 70 ℃ operating temperature is shifted to 100.003M only by the accuracy of the crystal oscillator itself. In order to make this deviation smaller, it is necessary to capture the temperature information of the crystal oscillator, so as to indirectly know the frequency offset, and compensate it, for example, the high precision is required to be within 100.0001MHz at 70 degree celsius working temperature, and the medium-high precision is within 100.001 MHz. In the high-precision compensation mode, the value of the load capacitor is directly adjusted to change the source frequency, so that the frequency output of MHz level and kHz level are kept at high precision.

And when the low power consumption mode is entered, detecting the temperature information of the crystal resonator in the MHz crystal oscillator through the temperature compensation module. And acquiring the frequency offset of the MHz-level crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the frequency dividing ratio of the kHz-level frequency divider according to the frequency offset.

Wherein, the modifying the frequency dividing ratio of the kHz level frequency divider according to the detected temperature information includes: detecting temperature information of the crystal oscillator through a temperature compensation module; and determining the frequency offset of the crystal oscillator according to the temperature information and the temperature characteristic of the resonator, and modifying the frequency dividing ratio of the frequency divider of the kHz level according to the obtained frequency offset so as to improve the frequency precision of the frequency output of the kHz level.

Optionally, if only one switching state is used for operation, the MHz clock driver may be turned off to turn off the MHz clock signal, and the kHz frequency divider and the kHz clock driver are kept operating. Therefore, the power consumption level is reduced to the uA level, so that the energy conservation and the power consumption reduction to the maximum degree are realized.

When the low-power-consumption compensation mode is entered, the capacitance value of the load capacitor is not modified, the frequency dividing ratio of the kHz-level frequency divider is adjusted in a lower-power-consumption mode to keep the stability of the frequency output of the kHz level at high precision, and the mode of closing the MHz-level frequency clock can be selected to reduce the overall power consumption to the uA level. In the embodiment, only a single MHz frequency crystal resonator is utilized, a high-precision MHz frequency clock and a low-power consumption 32.768kHz or other kHz frequency clocks can be generated, namely two-stage frequency output is realized through one crystal oscillator, and the two-stage frequency output can independently control a switch; under the scene that the frequency output needs temperature compensation, namely higher precision is required, the working conditions of high precision and low power consumption are considered simultaneously in multiple modes. In this embodiment, a MHz-level crystal oscillator with a common temperature stability is installed in the small-sized chip as an oscillation source to generate a MHz-level oscillation signal.

Wherein, the components of the crystal oscillator of MHz level include: crystal resonator, oscillating circuit and load capacitance. Specifically, the common effect of the crystal resonator, the oscillating circuit and the load capacitor can be utilized to generate the MHz-level oscillating signal. It should be noted that the principle and mechanism of generating the oscillation signal by using the common effect of the crystal resonator, the oscillation circuit and the load capacitor belong to the existing technologies, and are not described in detail in this embodiment.

When the oscillation signal of the MHz level generated by the crystal oscillator is input into the MHz level clock driver, the MHz level clock driver generates a MHz level clock signal. When the MHz oscillation signal generated by the crystal oscillator is input into the kHz level frequency divider, the kHz level frequency divider converts the MHz oscillation signal to the kHz level, inputs the converted oscillation signal into the kHz level clock driver and generates a kHz level clock signal. The MHz level and kHz level clock drivers can respectively control the switch states of two-level frequency output of the MHz level and the kHz level.

In this embodiment, frequency offset information of the crystal oscillator relative to the nominal frequency at a specific temperature is obtained according to the algorithm model, and frequency compensation is performed on the MHz-level or kHz-level clock signal in different compensation manners based on the frequency offset information. Specifically, in this embodiment, two compensation modes, an analog mode and a digital mode, may be adopted, and are respectively used for high-precision compensation and low-power compensation. The analog compensation method is to modify the load capacitance of the crystal oscillator to modify the frequency. The digital compensation method is to modify the frequency division ratio of the digital frequency divider to correct the frequency.

In this embodiment, the modifying the capacitance value of the load capacitor according to the detected temperature information so as to compensate the frequency offset of the crystal resonator generated along with the temperature change includes: and detecting the temperature information of the MHz-level crystal resonator through a temperature compensation module. And determining the frequency offset of the MHz-level crystal resonator according to the temperature information, and performing frequency compensation on the output frequency of the crystal resonator according to the obtained frequency offset. For example: in addition to the temperature, the capacitance of the load capacitor used with the crystal resonator in this embodiment is another factor that affects the frequency of the crystal resonator. Such as: a crystal resonator with a nominal 50MHz, 10pF load capacitance has a frequency of 50MHz at an actual load capacitance value of 10 pF. 49.99995MHz when the actual capacity value is 11 pF; the actual capacity is 50.00005MHz at 9 pF. In practical application, for example, at an operating temperature of 25 ℃, when the capacitance value of the load capacitor is 10pF, the frequency of the crystal resonator is 50MHz, and when the operating temperature is 85 ℃, the frequency of the crystal resonator is changed to 50.0025MHz, and the capacitance value of the load capacitor is adjusted to a higher value, for example, 15pF, so that the frequency offset caused by temperature change can be theoretically compensated. Namely, the frequency offset of the crystal resonator is corrected by adjusting the capacitance value of the load capacitor according to the temperature information, so that the temperature stability and the precision of the crystal oscillator are improved.

And when the low-power compensation mode is entered, acquiring the frequency offset of the MHz-level crystal resonator, determining the frequency dividing ratio of the kHz-level frequency divider according to the acquired frequency offset, updating, and then performing frequency compensation on the kHz-level clock signal by using the updated frequency dividing ratio. For example: at the working temperature of 25 ℃, the frequency of the crystal resonator is 50MHz, the oscillation signal of the crystal oscillator is also 50MHz correspondingly, and when the frequency dividing ratio of the kHz-level frequency divider is set to be 1000, the kHz-level clock signal is 50 MHz/1000-50 kHz. When the working temperature is 85 ℃, the frequency of the crystal resonator and the crystal oscillator is changed to 50.0025MHz, and the frequency deviation caused by the temperature change can be theoretically compensated by adjusting the frequency dividing ratio to 1000.05. The frequency output by the frequency division ratio can be adjusted according to the temperature information, so that the temperature stability and the precision of the frequency output by the kHz level are improved.

In this embodiment, a small-sized chip is further provided, and the architecture thereof is characterized as shown in fig. 6, and includes:

a MHz-level crystal oscillator with a common temperature stability is installed in the small-sized chip as an oscillation source and generates a MHz-level oscillation signal, and the components of the MHz-level crystal oscillator include: crystal resonator, oscillating circuit and load capacitance. The crystal oscillator of MHz level is connected with the clock driver of MHz level and the frequency divider of kHz level, and the frequency divider of kHz level is connected with the clock driver of kHz level.

After the MHz-level oscillation signal generated by the crystal oscillator is input into the MHz-level clock driver, the MHz-level clock driver outputs a MHz-level clock signal. After the MHz oscillation signal generated by the crystal oscillator is input into the kHz level frequency divider, the output of the kHz level frequency divider is converted into the oscillation signal at the kHz level, and then the oscillation signal is input into the kHz level clock driver, and the kHz level clock driver outputs the kHz level clock signal. Specifically, a MHz-level crystal resonator with common temperature stability is installed in the small-sized chip as an oscillation source, an on-chip oscillation circuit and a load capacitor are matched to generate a MHz-level oscillation signal, and the combination of the crystal resonator, the oscillation circuit and the load capacitor is a crystal oscillator. The MHz oscillation signal generated by the crystal oscillator is input into a MHz clock driver to generate a MHz clock signal and input into a kHz frequency divider. And the kHz level frequency divider is used for converting the MHz level oscillating signal to the kHz level and inputting the MHz level oscillating signal into the kHz level clock driver to generate a kHz level clock signal.

In practical applications, the system needs a high-precision clock signal in the normal operating mode and needs a low-power consumption clock signal in the standby mode, and therefore, one of the design difficulties of this embodiment is: how to use the same oscillation source to meet the requirements of different scenes. In this embodiment, adopt single crystal oscillator of MHz level as the oscillation source, the output of crystal oscillator can connect MHz level frequency clock driver and obtain MHz frequency clock output, or obtain kHz level frequency clock output behind kHz level frequency divider, and both can independent control switch enable.

The scheme of the embodiment can meet the high precision of the MHz level clock and also meet the medium and high precision of the kHz level clock meeting low power consumption. Therefore, when the system enters a standby state, the MHz-level clock is turned off, and the 32.768 kHz-level clock needs to work in the uA-level low-power-consumption compensation mode. That is, the present embodiment may have two working modes simultaneously, and in the high-precision and low-power-consumption scenarios, different compensation methods should be adopted: in the high-precision compensation mode, the temperature compensation module adjusts the load capacitance of the crystal resonator in a simulation mode according to the detected temperature information, so that the temperature compensation of the frequency is achieved, and the MHz and kHz frequency outputs can achieve high-precision stability; when the system needs to enter low-power-consumption compensation modes such as a standby state and the like, the MHz frequency clock can be independently closed, the kHz frequency output clock is kept in a working state and enters the low-power-consumption compensation mode, and in the low-power-consumption compensation mode, the compensation mode is switched from the adjustment of the load capacitance of the crystal resonator to the adjustment of the kHz frequency divider in a digital mode. To maintain moderate to high precision and to reduce power consumption to the uA level. Through different compensation modes, the integration scheme can perfectly replace the original scheme that two chips are required to be used, and the layout area and the material cost are greatly saved.

In this embodiment, a device for two-stage frequency output multi-mode control suitable for a small-sized chip is further provided, which includes:

the compensation triggering unit is used for triggering the temperature compensation module to operate when temperature compensation is needed, wherein the working mode of temperature compensation comprises the following steps: a high-precision compensation mode and a low-power consumption mode.

The high-precision compensation unit is used for detecting the temperature information of the crystal resonator in the MHz crystal oscillator through the temperature compensation module when entering the high-precision compensation mode; and acquiring the frequency offset of the MHz-level crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the capacitance value of a load capacitor in the MHz-level crystal oscillator according to the frequency offset.

The low-power compensation unit is used for detecting the temperature information of the crystal resonator in the MHz crystal oscillator through the temperature compensation module when entering the low-power mode; and acquiring the frequency offset of the MHz-level crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the frequency dividing ratio of the kHz-level frequency divider according to the frequency offset.

In this embodiment, a scheme of integrating low-power-consumption kHz and high-precision MHz-level frequency clocks into the same clock chip is an application block diagram of the integration scheme in a system, as shown in fig. 5, and the scheme can provide various advantages to the system: unified clock signal management: a single MHz frequency crystal resonator is utilized to generate a high-precision MHz frequency clock and a low-power consumption 32.768kHz or other kHz frequency clocks, so that the area required by the layout is greatly reduced; the MHz-level frequency clock and the kHz-level frequency clock can be independently controlled to be enabled, and the kHz-level frequency clock can enter a low-power-consumption compensation mode; under the low power consumption compensation mode, the frequency clock frequency divider of 32.768kHz or other kHz stages is adjusted in a pure digital mode to compensate the temperature of the output frequency.

The scheme of the embodiment has the advantages that: unified clock signal management, greatly reduce the area required by layout, and simultaneously can also reduce the whole power consumption. Moreover, the following functions are also required to achieve the effect of the discrete solution: the MHz level clock meets high precision; the kHz level clock meets the requirements of low power consumption and medium and high precision; when the system enters a standby state, the MHz level clock is turned off, and the 32.768kHz level clock needs to work in a uA level low-power consumption compensation mode.

Unifying the oscillation sources of the MHz and kHz order clocks to the same crystal resonator can maximize the size and cost required to reduce the layout. However, as described above, the system needs a high-precision clock signal in the normal operation mode and needs a low-power consumption clock signal in the standby mode, and the design difficulty of this scheme is how to use the same oscillation source to meet the requirements of different scenarios.

In high precision and low power consumption scenarios, different compensation approaches should be employed. The framework of the invention adopts a single crystal resonator with MHz level as an oscillation source, the output of the oscillation circuit of the crystal resonator can be connected with a frequency clock driver with MHz level to obtain the output of a clock with MHz level or obtain the output of a clock with kHz level after passing through a frequency divider with kHz level, and the two clock drivers can independently control the switch to enable.

Meanwhile, the scheme has two working modes, and in the high-precision compensation mode, the temperature compensation module achieves temperature compensation on frequency in a mode of adjusting the load capacitance of the crystal resonator according to detected temperature information, so that the MHz and kHz frequency outputs can achieve high-precision stability; when the system needs to enter a standby state, the MHz frequency clock can be independently closed, the kHz frequency output clock is kept in a working state, and the low-power compensation mode is entered. Through different compensation modes, the integration scheme can perfectly replace the original scheme that two chips are required to be used, and the layout area and the material cost are greatly saved.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the apparatus embodiment, since it is substantially similar to the method embodiment, it is relatively simple to describe, and reference may be made to some descriptions of the method embodiment for relevant points. The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. A double frequency output method suitable for a small-size chip is characterized in that the small-size chip adopts a single MHz-stage crystal oscillator as an oscillation source, the MHz-stage crystal oscillator is simultaneously connected with a MHz-stage clock driver and a kHz-stage frequency divider, wherein the switching state of MHz-stage frequency output is controlled by the MHz-stage clock driver, and the switching state of kHz-stage frequency output is controlled by the kHz-stage clock driver;

and after the currently required frequency output is confirmed, the switching state of the MHz-level frequency output and the switching state of the kHz-level frequency output are respectively controlled by the MHz-level clock driver and the kHz-level clock driver.

2. The method of claim 1, wherein the temperature compensation module is triggered to operate when temperature compensation is required, wherein the temperature compensation mode comprises: a high-precision compensation mode and a low-power consumption mode.

3. The method of claim 2, further comprising:

when entering the high-precision compensation mode, detecting the temperature information of the crystal resonator in the MHz crystal oscillator through the temperature compensation module;

and acquiring the frequency offset of the MHz-level crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the capacitance value of a load capacitor in the MHz-level crystal oscillator according to the frequency offset.

4. The method of claim 2, further comprising:

when entering the low power consumption mode, detecting temperature information of a crystal resonator inside the MHz crystal oscillator through the temperature compensation module;

and acquiring the frequency offset of the MHz-level crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the frequency dividing ratio of the kHz-level frequency divider according to the frequency offset.

5. The method according to claim 1, wherein a crystal oscillator of MHz level is installed in the small-sized chip as an oscillation source to generate an oscillation signal of MHz level;

the component parts of the crystal oscillator in the MHz level comprise: the device comprises a MHz-class crystal resonator, an oscillating circuit and a load capacitor.

6. The method according to claim 1 or 5, wherein when the oscillation signal of the MHz level generated by the MHz level crystal oscillator is input to the MHz level clock driver, the MHz level clock driver generates a MHz level frequency output;

when the MHz level crystal oscillator generates MHz oscillation signal and inputs the MHz level crystal oscillator into the kHz level frequency divider, the kHz level frequency divider converts the MHz level oscillation signal into kHz level oscillation signal, and inputs the converted kHz level oscillation signal into the kHz level clock driver and generates kHz level frequency output.

7. A small-sized chip, comprising:

a MHz level crystal oscillator is installed in the small-sized chip as an oscillation source and generates a MHz level oscillation signal, and the components of the MHz level crystal oscillator include: a crystal resonator, an oscillation circuit and a load capacitor;

the MHz level crystal oscillator is connected with a MHz level clock driver and a kHz level frequency divider, and the kHz level frequency divider is connected with a kHz level clock driver.

8. The small-sized chip according to claim 7, wherein the MHz-level clock driver generates a MHz-level frequency output after the MHz-level crystal oscillator generates the MHz-level oscillation signal;

after MHz oscillating signals generated by the MHz crystal oscillator are input into the kHz level frequency divider, the kHz level frequency divider outputs oscillating signals converted into kHz level oscillating signals, and then the oscillating signals are input into the kHz level clock driver, and the kHz level clock driver generates kHz level frequency output.

9. The small-sized chip according to claim 8, wherein the MHz-level clock driver is used for controlling the switching state of the MHz-level frequency output; the kHz level clock driver is used for controlling the switching state of the kHz level frequency output.

10. A dual frequency output device adapted for use with a small chip size, comprising:

the compensation triggering unit is used for triggering the temperature compensation module to operate when temperature compensation is needed, wherein the working mode of temperature compensation comprises the following steps: a high-precision compensation mode and a low-power consumption mode;

the high-precision compensation unit is used for detecting the temperature information of the crystal resonator in the MHz crystal oscillator through the temperature compensation module when entering the high-precision compensation mode; acquiring the frequency offset of the MHz crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the capacitance value of a load capacitor in the MHz crystal oscillator according to the frequency offset;

the low-power compensation unit is used for detecting the temperature information of the crystal resonator in the MHz crystal oscillator through the temperature compensation module when entering the low-power mode; and acquiring the frequency offset of the MHz-level crystal oscillator according to the detected temperature information and the temperature characteristic of the resonator, and modifying the frequency dividing ratio of the kHz-level frequency divider according to the frequency offset.

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