Frequency generation circuit, chip and electronic device

Abstract

The embodiment of the utility model provides a frequency generation circuit, a chip and electronic equipment, the frequency generation circuit comprises a first voltage end, an oscillator and a negative temperature coefficient voltage module, and the negative temperature coefficient voltage module is connected between the first voltage end and a second power end of the oscillator. The first voltage end and the negative temperature coefficient voltage module form a positive temperature coefficient power supply, so that a higher voltage can be provided for the second power supply end of the oscillator under the condition that the temperature rises, and the oscillation frequency of the oscillator is positively correlated with the voltage of the second power supply end, so that the oscillation efficiency of the oscillator is improved. The temperature influence on the carrier mobility can be counteracted, so that the influence on the oscillation frequency is reduced, the oscillation frequency of the oscillator does not change along with the rise of the temperature, and the stability of the oscillation frequency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a frequency generating circuit, a chip and an electronic device. Background Art

[0002] In applications, the output frequency of the oscillator will be affected by changes in process, temperature, power supply voltage, etc., and may not be able to achieve sufficient accuracy.

[0003] Among them, the ring oscillator in the oscillator is usually composed of n (n is an odd number greater than or equal to 3) stages of inverters connected in series head to tail. Due to the advantages of low power consumption, low phase noise, low footprint and easy synthesis with digital circuits, the ring oscillator has been widely used in practice. For example, in communication circuits and high-speed systems, it is usually used as an important component of the phase-locked loop (PLL) to generate a time reference; or in power circuits, it can generally be used as a charge pump (CP) clock or a delay module of a power control system.

[0004] However, the oscillation frequency of the ring oscillator may change under certain conditions, resulting in a decrease in the stability of the oscillation frequency. Therefore, it is necessary to provide a frequency generating circuit to improve the stability of the oscillation frequency of the ring oscillator. Utility Model Content

[0005] In view of the above problems, the embodiments of the present application provide a frequency generating circuit, a chip and an electronic device to solve the above technical problems.

[0006] In a first aspect, an embodiment of the present application provides a frequency generating circuit, which includes a first voltage terminal, an oscillator and a negative temperature coefficient voltage module, wherein the first power supply terminal of the oscillator is connected to the second voltage terminal; the input terminal of the negative temperature coefficient voltage module is connected to the first voltage terminal, and the output terminal of the negative temperature coefficient voltage module is connected to the second power supply terminal of the oscillator.

[0007] Optionally, the negative temperature coefficient voltage module includes a first transistor, a first electrode of the first transistor is connected to the first voltage terminal, and a control electrode of the first transistor is connected to the second electrode of the first transistor and the second power supply terminal of the oscillator.

[0008] Optionally, the negative temperature coefficient voltage module includes a diode, an anode of the diode is connected to the first voltage terminal, and a cathode of the diode is connected to the second power supply terminal of the oscillator.

[0009] Optionally, the frequency generating circuit further includes a switch module, and the switch module is connected between the output end of the negative temperature coefficient voltage module and the second power supply end of the oscillator.

[0010] Optionally, the switch module includes a second transistor, the source of the second transistor is connected to the output end of the negative temperature coefficient voltage module, the drain of the second transistor is connected to the second power supply end of the oscillator, the control electrode of the second transistor is connected to the third voltage end, and the second transistor is a P-channel transistor.

[0011] Optionally, the frequency generating circuit also includes a control module and a calibration module, the input end of the calibration module is connected to the output end of the negative temperature coefficient voltage module, the output end of the calibration module is connected to the second power supply end of the oscillator or the input end of the switch module, and the control end of the calibration module is connected to the control module.

[0012] Optionally, the calibration module includes at least one calibration unit connected to each other, the input end of at least one calibration unit is connected to the output end of the negative temperature coefficient voltage module, the output end of at least one calibration unit is connected to the second power supply end of the oscillator or the input end of the switch module, and the control end of each calibration unit is connected to the control module.

[0013] Optionally, the calibration unit includes a first resistor and a third transistor, one end of the first resistor is connected to the input end of the calibration unit, and the other end of the first resistor is connected to the output end of the calibration unit; the first electrode of the third transistor is connected to one end of the first resistor, the second electrode of the third transistor is connected to the other end of the first resistor, and the control electrode of the third transistor is connected to the control module.

[0014] Optionally, the first voltage terminal is used to provide a first constant voltage signal, and the second voltage terminal is used to provide a second constant voltage signal, and the potential of the first constant voltage signal is higher than the potential of the second constant voltage signal.

[0015] In a second aspect, an embodiment of the present application further provides a chip, which includes the above-mentioned frequency generating circuit.

[0016] In a third aspect, an embodiment of the present application further provides an electronic device, which includes a device body and the above-mentioned frequency generating circuit or the above-mentioned chip arranged in the device body.

[0017] The frequency generating circuit, chip and electronic device provided in the embodiments of the present application connect a negative temperature coefficient voltage module between the first voltage terminal and the second power supply terminal of the oscillator, so that the first voltage terminal and the negative temperature coefficient voltage module form a positive temperature coefficient power supply, thereby providing a higher voltage to the second power supply terminal of the oscillator when the temperature rises. Since the oscillation frequency of the oscillator is positively correlated with the voltage of its second power supply terminal, the influence of the temperature on the oscillation frequency can be offset, so that the oscillation frequency of the oscillator does not change with the increase of temperature, thereby improving the stability of the oscillation frequency.

[0018] Furthermore, compared to achieving low temperature drift of the oscillation frequency under the condition of clamping of a reference current source, the frequency generating circuit provided in the embodiment of the present application can also achieve low temperature drift of the oscillation frequency without using a reference current source clamp, which not only simplifies the circuit structure but also reduces the cost and occupied area.

[0019] These and other aspects of the present application will become more clearly understood in the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A ring oscillator in the related art is shown.

[0022] Figure 2 Shows Figure 1 The inverter in .

[0023] Figure 3 A first principle block diagram of a frequency generating circuit provided in an embodiment of the present application is shown.

[0024] Figure 4 A first circuit diagram of a negative temperature coefficient voltage module provided in an embodiment of the present application is shown.

[0025] Figure 5 A second circuit diagram of a negative temperature coefficient voltage module provided in an embodiment of the present application is shown.

[0026] Figure 6 A second principle block diagram of a frequency generating circuit provided in an embodiment of the present application is shown.

[0027] Figure 7 A circuit diagram of a switch module provided in an embodiment of the present application is shown.

[0028] Figure 8 A third principle block diagram of the frequency generating circuit provided in an embodiment of the present application is shown.

[0029] Fig. 9 A fourth principle block diagram of the frequency generating circuit provided in an embodiment of the present application is shown.

[0030] Fig.10 A circuit diagram of a calibration module provided in an embodiment of the present application is shown.

[0031] Fig.11A first circuit diagram of a frequency generating circuit provided in an embodiment of the present application is shown.

[0032] Fig.12 A second circuit diagram of a frequency generating circuit provided in an embodiment of the present application is shown.

[0033] Fig.13 The structure diagram of the chip provided in the embodiment of the present application is shown.

[0034] Fig.14 A structural diagram of an electronic device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0036] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0037] In the embodiments of the present application, it should be noted that, in this article, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0038] Moreover, the terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0039] In the description of the embodiments of the present application, words such as "example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "example" or "for example" in the embodiments of the present application is not to be interpreted as being more preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to present relative concepts in a clear manner.

[0040] In addition, the "plurality" in the embodiments of the present application refers to two or more than two. In view of this, in the embodiments of the present application, "plurality" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two or more. For example, including at least one means including one, two or more, and there is no limit on which ones are included. For example, including at least one of A, B and C, then A, B, C, A and B, A and C, B and C, or A, B and C can be included.

[0041] It should be noted that in the embodiments of the present application, "connection" can be understood as electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components.

[0042] The first pole / first end of each transistor used in the embodiments of the present application is one of the source and the drain, and the second pole / second end of each transistor is the other of the source and the drain. Since the source and drain of the transistor can be symmetrical in structure, the source and drain thereof can be structurally indistinguishable, that is, the first pole / first end and the second pole / second end of the transistor in the embodiments of the present application can be structurally indistinguishable. Exemplarily, in the case where the transistor is a P-type transistor, the first pole / first end of the transistor is the source, and the second pole / second end is the drain; exemplarily, in the case where the transistor is an N-type transistor, the first pole / first end of the transistor is the drain, and the second pole / second end is the source.

[0043] The output frequency of an oscillator usually changes with the change of its own power supply voltage, especially the RC oscillator and the ring oscillator in the oscillator. This application takes the ring oscillator as an example for detailed description, but the inventive concept of this application can also be applied to the RC oscillator and can achieve the same or similar technical effects.

[0044] Figure 1 The ring oscillator in the related art is shown. The ring oscillator is usually composed of n (n is an odd number greater than or equal to 3) stages of inverters connected in series. When working, the positive power supply terminal of the ring oscillator is connected to the voltage VDD, and the negative power supply terminal of the ring oscillator is connected to the zero potential. Among them, Figure 1By way of example, n is set equal to 5.

[0045] Among them, Figure 2 As shown, the inverter includes a first field effect transistor MP1 and a second field effect transistor MN1, the source of the first field effect transistor MP1 is connected to the voltage VDD, the drain of the first field effect transistor MP1 is connected to the drain of the second field effect transistor MN1, the source of the second field effect transistor MN1 is connected to the zero potential, and the gate of the first field effect transistor MP1 is connected to the gate of the second field effect transistor MN1 and has a potential V_i. A parasitic capacitor C is formed at the connection between the drain of the first field effect transistor MP1 and the drain of the second field effect transistor MN1. The first field effect transistor MP1 is a P-channel field effect transistor, and the second field effect transistor MN1 is an N-channel field effect transistor.

[0046] The calculation method of the oscillation frequency ω of the ring oscillator is shown in Equation 1-1:

[0047]

[0048] Among them, T D is the delay time of each stage of inverter (it is assumed here that the delay time of each stage of inverter is the same).

[0049] according to Figure 2 Equation 1-2 can be obtained as follows:

[0050] I×T D =C×VDD (1-2)

[0051] Wherein, I is the current flowing through the first field effect transistor MP1 or the second field effect transistor MN1. C represents the capacitance of the parasitic capacitor C.

[0052] The I charges and discharges the parasitic capacitor C, thereby forming a delay time T in each inverter stage. D In a ring oscillator with inverters in series, the parasitic capacitance C between stages changes relatively little in PVT (process, voltage and temperature). Therefore, in order to reduce the frequency temperature drift of the ring oscillator, a reference current source with minimal change under PVT is generally chosen to reduce the frequency temperature drift of the ring oscillator. However, the frequency change of the ring oscillator without the reference current source clamping under PVT is quite large, as analyzed below:

[0053] like Figure 2 Assume that the absolute value of the threshold voltage (V TH ) are the same, and the carrier mobilities are μ p , μ nWhen V_i is at VDD / 2, the inverter is in the push-pull amplifier working mode. At this time, I (the sum of the currents flowing through the first field effect transistor MP1 and the second field effect transistor MN1) is the largest. It is also the inverter flipping stage and is the main component of the delay. Therefore, there is:

[0054]

[0055] Among them, C OX is the dielectric constant, is the width-to-length ratio of the channel of the second field effect transistor MN1, is the width-to-length ratio of the channel of the first field effect transistor MP1.

[0056] Equation 1-3 is transformed into equation 1-4, as follows:

[0057]

[0058] Substituting equation 1-4 into equation 1-2, we obtain equation 1-5, as follows:

[0059]

[0060] Substituting equation 1-5 into equation 1-1, we obtain equation 1-6, as follows:

[0061]

[0062] From equation 1-6, we can see that when VDD>2V TH In the case of p and μ n All of them are positively correlated.

[0063] Among them, temperature change has the greatest impact on carrier mobility, and the relationship between carrier mobility and temperature is negatively correlated, that is, carrier mobility decreases as temperature increases. Therefore, when other conditions remain unchanged, as the temperature increases, the oscillation frequency of the ring oscillator decreases.

[0064] Based on this, in order to offset the influence of the temperature-dependent characteristic of carrier mobility and maintain the relative stability of the oscillation frequency of the oscillator, the present embodiment provides a frequency generating circuit 100, see Figures 3 to 12The frequency generating circuit 100 includes a first voltage terminal VLDO, an oscillator 20 and a negative temperature coefficient voltage module 10. By connecting a negative temperature coefficient voltage module 10 between the first voltage terminal VLDO and the second power supply terminal of the oscillator 20, the first voltage terminal VLDO and the negative temperature coefficient voltage module 10 form a positive temperature coefficient power supply, so that when the temperature rises, a higher voltage (VDD) can be provided to the second power supply terminal of the oscillator 20. Since the oscillation frequency of the oscillator 20 is positively correlated with the voltage of its second power supply terminal, the influence of the carrier mobility being affected by the temperature on the oscillation frequency can be offset, so that the oscillation frequency of the oscillator 20 does not change with the increase of temperature, thereby improving the stability of the oscillation frequency.

[0065] The present application embodiment provides a frequency generating circuit 100. Figures 3 to 12 ,like Figure 3 As shown, the frequency generating circuit 100 includes a first voltage terminal VLDO, an oscillator 20 and a negative temperature coefficient voltage module 10, the first power supply terminal of the oscillator 20 is connected to the second voltage terminal GND, the input terminal of the negative temperature coefficient voltage module 10 is connected to the first voltage terminal VLDO, and the output terminal of the negative temperature coefficient voltage module 10 is connected to the second power supply terminal of the oscillator 20.

[0066] It can be understood that the frequency generating circuit 100 provided in the embodiment of the present application connects a negative temperature coefficient voltage module 10 between the first voltage terminal VLDO and the second power supply terminal of the oscillator 20, so that the first voltage terminal VLDO and the negative temperature coefficient voltage module 10 form a positive temperature coefficient power supply, thereby providing a higher voltage to the second power supply terminal of the oscillator 20 when the temperature rises. Since the oscillation frequency of the oscillator 20 is positively correlated with the voltage of its second power supply terminal, the influence of the carrier mobility being affected by the temperature on the oscillation frequency can be offset, so that the oscillation frequency of the oscillator 20 does not change with the increase of temperature, thereby improving the stability of the oscillation frequency.

[0067] Furthermore, compared to achieving low temperature drift of the oscillation frequency under the condition of clamping of a reference current source, the frequency generating circuit 100 provided in the embodiment of the present application can also achieve low temperature drift of the oscillation frequency without using a reference current source clamp, which not only simplifies the circuit structure but also reduces the cost and occupied area.

[0068] It should be noted that the oscillator 20 may be schematically a ring oscillator, or may be other applicable oscillators, such as an RC oscillator.

[0069] The voltage drop of the negative temperature coefficient voltage module 10 will decrease as the temperature increases. Therefore, the difference between the potential of the first voltage terminal VLDO and the voltage drop of the negative temperature coefficient voltage module 10 will become larger, so that the first voltage terminal VLDO and the negative temperature coefficient voltage module 10 can form a positive temperature coefficient power supply that outputs a higher potential as the temperature increases. This can not only reverse the trend of the oscillation frequency decreasing as the temperature increases, but also increase the oscillation frequency so that the oscillation frequency can remain unchanged.

[0070] Optionally, the first voltage terminal VLDO is used to provide a first constant voltage signal, so that the potential of the first power supply terminal is more stable and will not change with the change of temperature, further improving the stability of the oscillation frequency. Exemplarily, the first voltage terminal VLDO can be the output terminal of a low voltage difference linear regulator, which can provide an output voltage with zero temperature drift. The second voltage terminal GND is used to provide a second constant voltage signal, for example, a zero potential signal or a low potential signal. The potential of the first constant voltage signal is higher than the potential of the second constant voltage signal, so as to provide a suitable operating voltage for the oscillator 20.

[0071] Alternatively, if Figure 4 As shown, the negative temperature coefficient voltage module 10 includes a first transistor Q, a first electrode of the first transistor Q is connected to the first voltage terminal VLDO, and a control electrode of the first transistor Q is connected to the second electrode of the first transistor Q and the second power supply terminal of the oscillator 20.

[0072] It should be noted that the first transistor Q is connected in a manner similar to the diode D1, and its voltage drop is negatively correlated with the change in temperature, that is, the voltage drop decreases as the temperature increases. In some embodiments, the first transistor Q can be a triode, the first pole is the collector, the second pole is the emitter, and the control pole is the base.

[0073] Alternatively, if Figure 5 As shown, the negative temperature coefficient voltage module 10 includes a diode D1 , an anode of the diode D1 is connected to the first voltage terminal VLDO, and a cathode of the diode D1 is connected to the second power supply terminal of the oscillator 20 .

[0074] It should be noted that the negative temperature coefficient voltage module 10 uses a diode D1 to achieve a negative correlation between its voltage drop and temperature, that is, the voltage drop decreases as the temperature increases.

[0075] Alternatively, if Figure 6 As shown, the frequency generating circuit 100 further includes a switch module 30 , which is connected in series between the output terminal of the negative temperature coefficient voltage module 10 and the second power supply terminal of the oscillator 20 .

[0076] It should be noted that, in this embodiment, the working state of the oscillator 20, that is, whether to work, can be controlled when the first voltage terminal VLDO continues to supply power. For example, when the switch module 30 is disconnected, the oscillator 20 can be controlled to stop working; or, when the switch module 30 is turned on, the oscillator 20 can be controlled to work.

[0077] Alternatively, if Figure 7 As shown, the switch module 30 includes a second transistor MP2, a source of the second transistor MP2 is connected to the output end of the negative temperature coefficient voltage module 10, a drain of the second transistor MP2 is connected to the second power supply end of the oscillator 20, a control electrode of the second transistor MP2 is connected to the third voltage end, and the second transistor MP2 is a P-channel transistor.

[0078] It should be noted that the present embodiment adopts a P-channel transistor, and the source of the second transistor MP2 is connected to the output terminal of the negative temperature coefficient voltage module 10. When the potential of the third voltage terminal is stable, the gate-source voltage difference of the second transistor MP2 can be stabilized, so that the input current provided to the oscillator 20 is more stable, and the charging and discharging of the parasitic capacitance by the oscillator 20 is more stable, thereby increasing the delay time (TD) of each inverter INV, which is conducive to further improving the stability of the oscillation frequency. Preferably, the second transistor MP2 can be a P-channel field effect transistor, and the third voltage terminal can be a ground terminal, and a zero potential signal is connected to control the conduction of the second transistor MP2; or, the third voltage terminal is suspended or a high potential signal is connected to control the cut-off of the second transistor MP2.

[0079] Optionally, the third voltage terminal may be shared with the second voltage terminal GND to reduce the number of used voltage terminals of the frequency generating circuit 100 .

[0080] Alternatively, if Figure 8 , Fig. 9 As shown, the frequency generating circuit 100 also includes a control module 50 and a calibration module 40, the input end of the calibration module 40 is connected to the output end of the negative temperature coefficient voltage module 10, the output end of the calibration module 40 is connected to the second power supply end of the oscillator 20 or the input end of the switch module 30, and the control end of the calibration module 40 is connected to the control module 50.

[0081] It should be noted that in Figure 8 In the embodiment, the output terminal of the calibration module 40 is connected to the second power supply terminal of the oscillator 20. Fig. 9In the embodiment, the output end of the calibration module 40 is connected to the input end of the switch module 30. In some other embodiments, the negative temperature coefficient voltage module 10, the calibration module 40 and the switch module 30 can be connected in series between the first voltage terminal VLDO and the second power supply terminal of the oscillator 20, and the order or position between them can be adjusted, which can still make the potential of the second power supply terminal of the oscillator 20 increase with the increase of temperature, thereby maintaining the stability of the oscillation frequency.

[0082] The calibration module 40 may adjust the potential of the second power supply terminal of the oscillator 20 to reduce the offset of the oscillation frequency at each process angle.

[0083] Alternatively, if Fig.10 As shown, the calibration module 40 includes at least one calibration unit 41 connected to each other, the input end of at least one calibration unit 41 is connected to the output end of the negative temperature coefficient voltage module 10, the output end of at least one calibration unit 41 is connected to the second power supply end of the oscillator 20 or the input end of the switch module 30, and the control end of each calibration unit 41 is connected to the control module 50.

[0084] It should be noted that the more the calibration units 41 are, the greater the adjustment amount of the potential of the second power supply terminal of the oscillator 20. The control module 50 can control the resistance of each calibration unit 41, thereby controlling the adjustment of the overall resistance of the calibration module 40, and can adjust the voltage drop of the calibration module 40, thereby increasing the adjustment amount of the potential of the second power supply terminal of the oscillator 20.

[0085] Among them, for example, Fig.10 As shown, the at least one calibration unit 41 includes at least one of a first calibration unit 45 , a second calibration unit 46 , a third calibration unit 47 and a fourth calibration unit 48 .

[0086] Optionally, the first calibration unit 45 includes a first resistor R1 and a third transistor M1, one end of the first resistor R1 is connected to the input end of the first calibration unit 45, and the other end of the first resistor R1 is connected to the output end of the first calibration unit 45; the first electrode of the third transistor M1 is connected to one end of the first resistor R1, the second electrode of the third transistor M1 is connected to the other end of the first resistor R1, and the control electrode of the third transistor M1 is connected to the control module 50.

[0087] The second calibration unit 46 includes a second resistor R2 and a fourth transistor M2, one end of the second resistor R2 is connected to the output end of the first calibration unit 45 and the input end of the second calibration unit 46, and the other end of the second resistor R2 is connected to the output end of the second calibration unit 46; the first electrode of the fourth transistor M2 is connected to one end of the second resistor R2, the second electrode of the fourth transistor M2 is connected to the other end of the second resistor R2, and the control electrode of the fourth transistor M2 is connected to the control module 50.

[0088] The third calibration unit 47 includes a third resistor R3 and a fifth transistor M3, one end of the third resistor R3 is connected to the output end of the second calibration unit 46 and the input end of the third calibration unit 47, and the other end of the third resistor R3 is connected to the output end of the third calibration unit 47; the first electrode of the fifth transistor M3 is connected to one end of the third resistor R3, the second electrode of the fifth transistor M3 is connected to the other end of the third resistor R3, and the control electrode of the fifth transistor M3 is connected to the control module 50.

[0089] The fourth calibration unit 48 includes a fourth resistor R4 and a sixth transistor M4, one end of the fourth resistor R4 is connected to the output end of the third calibration unit 47 and the input end of the fourth calibration unit 48, and the other end of the fourth resistor R4 is connected to the output end of the fourth calibration unit 48; the first electrode of the sixth transistor M4 is connected to one end of the fourth resistor R4, the second electrode of the sixth transistor M4 is connected to the other end of the fourth resistor R4, and the control electrode of the sixth transistor M4 is connected to the control module 50.

[0090] The input end of the first calibration unit 45 serves as the input end of the calibration module 40 , and the output end of the fourth calibration unit 48 serves as the output end of the calibration module 40 .

[0091] Among them, the resistance values ​​of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 can be the same or different. Preferably, the resistance values ​​of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are 1R, 2R, 4R, and 8R respectively. In this way, under the combination switch of the third transistor M1 to the sixth transistor M4, the resistance of the calibration module 40 can be 0R-15R, and R is the unit resistance.

[0092] The third transistor M1 to the sixth transistor M4 may be N-channel or P-channel field effect transistors. The control module 50 may be a register, which stores corresponding data 0, 1, and Fig.10 Taking each transistor in the figure as a P-channel field effect transistor, when the gate of the corresponding transistor is connected to 0, the transistor is turned on; when the gate of the corresponding transistor is connected to 1, the transistor is turned off.

[0093] Among them, if the first resistor R1 to the fourth resistor R4 are resistors with negative temperature coefficients, the positive temperature correlation of the potential of the second power supply terminal of the oscillator 20 can be further enhanced, that is, as the temperature increases, the potential of the second power supply terminal of the oscillator 20 rises faster, which is more conducive to improving the stability of the oscillation frequency.

[0094] It should be noted that when the oscillation frequency is too high, the resistance of the calibration module 40 can be increased to maintain the stability of the oscillation frequency; or, when the oscillation frequency is too low, the resistance of the calibration module 40 can be reduced to maintain the stability of the oscillation frequency.

[0095] like Fig.11 As shown, in the absence of the calibration module 40, the frequency generating circuit 100 reduces the voltage drop of the first transistor Q in the negative temperature coefficient voltage module 10 as the temperature increases, so that the difference between the potential of the first voltage terminal VLDO and the voltage drop of the negative temperature coefficient voltage module 10 increases as the temperature increases, and then when the second transistor MP2 in the switch module 30 is turned on, the potential of the second power supply terminal of each inverter INV in the oscillator 20 increases as the temperature increases, which can maintain the oscillation frequency of the oscillator 20 stable.

[0096] like Fig.12 As shown, in the case of having a calibration module 40, Fig.11 On this basis, the frequency generating circuit 100 can maintain the stability of the oscillation frequency by increasing the resistance of the calibration module 40 when the oscillation frequency is too high; or, when the oscillation frequency is too low, the resistance of the calibration module 40 can be reduced to maintain the stability of the oscillation frequency.

[0097] In one embodiment, if Fig.13 As shown, the embodiment of the present application further provides a chip 200 , and the chip 200 includes the above-mentioned frequency generating circuit 100 .

[0098] The chip 200 may also be referred to as an integrated circuit (IC). The chip 200 may be, but is not limited to, a SOC (System on Chip) chip or a SIP (system in package) chip.

[0099] It can be understood that the chip 200 provided in the embodiment of the present application, since it includes the above-mentioned frequency generating circuit 100, can also connect a negative temperature coefficient voltage module 10 between the first voltage terminal VLDO and the second power supply terminal of the oscillator 20, so that the first voltage terminal VLDO and the negative temperature coefficient voltage module 10 form a positive temperature coefficient power supply, thereby providing a higher voltage to the second power supply terminal of the oscillator 20 when the temperature rises. Since the oscillation frequency of the oscillator 20 is positively correlated with the voltage of its second power supply terminal, the influence of the carrier mobility being affected by temperature on the oscillation frequency can be offset, so that the oscillation frequency of the oscillator 20 does not change with the increase in temperature, thereby improving the stability of the oscillation frequency.

[0100] Furthermore, compared to achieving low temperature drift of the oscillation frequency under the condition of clamping of a reference current source, the frequency generating circuit 100 provided in the embodiment of the present application can also achieve low temperature drift of the oscillation frequency without using a reference current source clamp, which not only simplifies the circuit structure but also reduces the cost and occupied area.

[0101] In one embodiment, if Fig.14 As shown, an embodiment of the present application further provides an electronic device 300, which includes a device body and the above-mentioned frequency generating circuit 100 or the above-mentioned chip 200 arranged in the device body.

[0102] It can be understood that the electronic device 300 provided in the embodiment of the present application, since it includes the above-mentioned frequency generating circuit 100 or chip 200, can also connect a negative temperature coefficient voltage module 10 between the first voltage terminal VLDO and the second power supply terminal of the oscillator 20, so that the first voltage terminal VLDO and the negative temperature coefficient voltage module 10 form a positive temperature coefficient power supply, thereby providing a higher voltage to the second power supply terminal of the oscillator 20 when the temperature rises. Since the oscillation frequency of the oscillator 20 is positively correlated with the voltage of its second power supply terminal, the influence of the carrier mobility being affected by temperature on the oscillation frequency can be offset, so that the oscillation frequency of the oscillator 20 does not change with the increase in temperature, thereby improving the stability of the oscillation frequency.

[0103] Furthermore, compared to achieving low temperature drift of the oscillation frequency under the condition of clamping of a reference current source, the frequency generating circuit 100 provided in the embodiment of the present application can also achieve low temperature drift of the oscillation frequency without using a reference current source clamp, which not only simplifies the circuit structure but also reduces the cost and occupied area.

[0104] It should be noted that the electronic device 300 may be, but is not limited to, a weight scale, a body fat scale, a nutrition scale, an infrared electronic thermometer, a pulse oximeter, a human body composition analyzer, a mobile power supply, a wireless charger, a fast charger, a car charger, an adapter, a display, a USB (Universal Serial Bus) docking station, a stylus, a true wireless headset, a car console, a car, a smart wearable device, a mobile terminal, and a smart home device. Smart wearable devices include, but are not limited to, smart watches, smart bracelets, and cervical massagers. Mobile terminals include, but are not limited to, smart phones, laptops, tablet computers, and POS (point of sales terminal). Smart home devices include, but are not limited to, smart sockets, smart rice cookers, smart sweepers, and smart lights.

[0105] The above are only preferred embodiments of the present application, and are not intended to limit the present application in any form. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technical personnel in the field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A frequency generating circuit, characterized in that: The frequency generating circuit comprises: A first voltage terminal, the first voltage terminal is used to provide a first constant voltage signal; An oscillator, wherein a first power supply terminal of the oscillator is connected to a second voltage terminal; A negative temperature coefficient voltage module, wherein the input end of the negative temperature coefficient voltage module is connected to the first voltage end, and the output end of the negative temperature coefficient voltage module is connected to the second power supply end of the oscillator.

2. The frequency generating circuit according to claim 1, wherein: The negative temperature coefficient voltage module includes a first transistor, a first electrode of the first transistor is connected to the first voltage terminal, and a control electrode of the first transistor is connected to a second electrode of the first transistor and a second power supply terminal of the oscillator.

3. The frequency generating circuit according to claim 1, wherein: The negative temperature coefficient voltage module includes a diode, an anode of the diode is connected to the first voltage terminal, and a cathode of the diode is connected to the second power supply terminal of the oscillator.

4. The frequency generating circuit according to claim 1, wherein: The frequency generating circuit further comprises a switch module, and the switch module is connected between the output terminal of the negative temperature coefficient voltage module and the second power supply terminal of the oscillator.

5. The frequency generating circuit according to claim 4, wherein: The switch module includes a second transistor, a source of the second transistor is connected to the output end of the negative temperature coefficient voltage module, a drain of the second transistor is connected to the second power supply end of the oscillator, a control electrode of the second transistor is connected to the third voltage end, and the second transistor is a P-channel transistor.

6. The frequency generating circuit according to claim 1 or 4, characterized in that: The frequency generating circuit also includes a control module and a calibration module, the input end of the calibration module is connected to the output end of the negative temperature coefficient voltage module, the output end of the calibration module is connected to the second power supply end of the oscillator or the input end of the switch module, and the control end of the calibration module is connected to the control module.

7. The frequency generating circuit according to claim 6, wherein: The calibration module includes at least one calibration unit connected to each other, the input end of the at least one calibration unit is connected to the output end of the negative temperature coefficient voltage module, the output end of the at least one calibration unit is connected to the second power supply end of the oscillator or the input end of the switch module, and the control end of each calibration unit is connected to the control module.

8. The frequency generating circuit according to claim 7, wherein: The calibration unit comprises: a first resistor, one end of the first resistor being connected to the input end of the calibration unit, and the other end of the first resistor being connected to the output end of the calibration unit; A third transistor, wherein a first electrode of the third transistor is connected to one end of the first resistor, a second electrode of the third transistor is connected to the other end of the first resistor, and a control electrode of the third transistor is connected to the control module.

9. The frequency generating circuit according to any one of claims 1 to 5, characterized in that: The second voltage terminal is used to provide a second constant voltage signal, and the potential of the first constant voltage signal is higher than the potential of the second constant voltage signal.

10. A chip, characterized in that: The chip comprises the frequency generating circuit according to any one of claims 1-9.

11. An electronic device, characterized in that: The electronic device comprises a device body and a frequency generating circuit as described in any one of claims 1 to 9 or a chip as described in claim 10, which is arranged in the device body.

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