A Colpitts crystal oscillator amplitude detection device and its detection and calibration method

Abstract

This disclosure provides a Colpitts crystal oscillator amplitude detection device and its detection and calibration method. The Colpitts crystal oscillator amplitude detection device includes: a bias voltage and offset voltage detection terminal, used to connect to the output pin of the quartz crystal of the Colpitts oscillator under test via a connecting resistor, to detect the offset voltage near the connecting resistor end, and to adjust the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test; the Colpitts crystal oscillator amplitude detection device is configured to: by adjusting the bias voltage, make the offset voltage increase from small to large until it becomes constant to a critical state. The Colpitts crystal oscillator amplitude detection device provided in the embodiments of this disclosure is intended to accurately and effectively obtain the amplitude information of the Colpitts oscillator without adding any additional resistive or capacitive load to the oscillator itself.

Description

Technical Field

[0001] This disclosure relates to the field of analog integrated circuit technology, specifically to a Colpitts crystal oscillator amplitude detection device and its detection and calibration method. Background Technology

[0002] Crystal oscillators are an indispensable and crucial module in integrated circuits. They provide the clock for processors and a high-performance reference clock for the frequency synthesizers of RF transceiver systems. Taking RF transceiver circuits as an example, if the crystal oscillation amplitude is too small, it will significantly degrade the phase noise of the crystal circuit, affecting RF transceiver performance. Conversely, if the crystal oscillation amplitude is too large, it will reduce the crystal's lifespan, thereby shortening the equipment's service life. Therefore, it is essential to introduce a crystal amplitude calibration device.

[0003] To calibrate the crystal oscillation amplitude, the first step is to read the crystal's amplitude information. Crystal oscillators are based on the basic three-point oscillator, with the Pierce oscillator and Colpitts oscillator being the most commonly used types. The Pierce oscillator connects to the crystal pins via xtal_in and xtal_out, and amplitude information can be effectively read using a simple differential amplitude detection circuit. Amplitude calibration is then performed by adjusting the crystal oscillator's operating current. The Colpitts crystal oscillator has only one crystal pin connected to the circuit, offering advantages such as no need for additional load capacitors, large oscillation amplitude, and good phase noise. However, its large amplitude detection circuit has always been a challenge in Colpitts circuit design. Furthermore, unlike the Pierce oscillator, the Colpitts oscillator is highly sensitive to parasitic capacitance introduced by the oscillation circuit; parasitic capacitance affects the oscillation amplitude, leading to amplitude detection distortion. Moreover, some methods for obtaining the DC voltage output from the Colpitts oscillator's quartz crystal output pins can still become additional sources of interference.

[0004] Therefore, Colpitts oscillators require a large-amplitude detection circuit that is free of parasitic capacitance, and in particular, does not add any resistive or capacitive load to the oscillator itself, as well as a matching detection and calibration method.

[0005] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0006] To address at least one of the aforementioned problems, as well as one or more other potential problems, this disclosure proposes a Colpitts crystal oscillator amplitude detection device designed to accurately and effectively acquire the amplitude information of the Colpitts oscillator without adding any additional resistive or capacitive load to the oscillator itself.

[0007] In a first aspect of this disclosure, a Colpitts crystal oscillator amplitude detection device is provided. The Colpitts crystal oscillator amplitude detection device includes: a bias voltage and offset voltage detection terminal, which is connected to the output pin of the quartz crystal of the Colpitts oscillator under test via a connecting resistor, to detect the offset voltage near one end of the connecting resistor and to adjust the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test; the Colpitts crystal oscillator amplitude detection device is configured such that by adjusting the bias voltage, the offset voltage gradually increases until it reaches a critical state of constant value.

[0008] Furthermore, in some embodiments, the critical state of adjusting the bias voltage to make the offset voltage increase from small to large until it remains constant includes: adjusting the bias voltage so that the offset voltage changes with the bias voltage; increasing the applied bias voltage so that the offset voltage gradually increases until it just stops changing; and obtaining the amplitude value of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test based on the bias voltage value of the critical state and the conduction voltage value of the electrostatic protection diode of the Colpitts oscillator under test.

[0009] Furthermore, in some embodiments, the Colpitts crystal oscillator amplitude detection device further includes: an electrostatic protection diode forward voltage acquisition terminal, used to connect with a detection circuit of the same type of electrostatic protection diode in the Colpitts oscillator under test, so as to detect the forward voltage of the electrostatic protection diode of the same type as the Colpitts oscillator under test, thereby obtaining the forward voltage value of the electrostatic protection diode of the Colpitts oscillator under test.

[0010] Furthermore, in some embodiments, the Colpitts oscillator under test includes: a PMOS transistor with its drain grounded, the gate of which is connected to the output pin of a quartz crystal, and an electrostatic discharge protection diode disposed between the gate and drain of the PMOS transistor; a connecting resistor having a first terminal and a second terminal, the first terminal of which is connected to the gate of the PMOS transistor, and the second terminal of which is connected to the bias voltage and offset voltage detection terminals; and a bias current whose output terminal is connected to the source of the PMOS transistor.

[0011] Furthermore, in some embodiments, the aforementioned bias current is set to an adjustable bias current.

[0012] Furthermore, in some embodiments, the Colpitts crystal oscillator amplitude detection device further includes: a bias current control terminal, which is connected to the adjustable bias current of the Colpitts oscillator under test, so as to control the voltage waveform amplitude output by the output pin of the quartz crystal of the Colpitts oscillator under test by controlling the adjustable bias current of the Colpitts oscillator under test.

[0013] In a second aspect of this disclosure, an amplitude detection method for the aforementioned device is also provided. The amplitude detection method includes: detecting an offset voltage near one end of the connecting resistor and a bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test; adjusting the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test; when the offset voltage decreases as the bias voltage increases, increasing the applied bias voltage so that the offset voltage gradually increases until it just stops changing; and obtaining the amplitude value of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test based on the bias voltage value at the critical state and the conduction voltage value of the electrostatic protection diode of the Colpitts oscillator under test.

[0014] In a third aspect of this disclosure, an amplitude calibration method for the aforementioned device is provided, the amplitude calibration method comprising: determining a target amplitude value of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test; determining a target bias voltage adjustment value based on the target amplitude value of the voltage waveform, and adjusting the applied bias voltage to the determined target bias voltage adjustment value; adjusting the bias current of the Colpitts oscillator under test such that the amplitude of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test is sufficiently large so that the offset voltage decreases as the bias current increases; and adjusting and decreasing the bias current such that the offset voltage gradually increases until it just stops changing.

[0015] In a fourth aspect of this disclosure, an electronic device is further provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the steps of the method described above.

[0016] In a fifth aspect of this disclosure, a computer-readable storage medium is further provided, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the steps of the method described above.

[0017] This disclosure has the following advantages over the prior art:

[0018] In some embodiments, the Colpitts crystal oscillator amplitude detection device can detect the offset voltage near the connecting resistor and adjust the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test using only the bias voltage and offset voltage detection terminals. Furthermore, the Colpitts crystal oscillator amplitude detection device can accurately and effectively obtain the amplitude information of the Colpitts oscillator without adding any additional resistive or capacitive load to the oscillator itself by adjusting the aforementioned bias voltage from a small value to a critical state where the offset voltage remains constant. Further, by combining this with adjusting the adjustable bias current of the Colpitts oscillator under test via the bias current control terminal, amplitude calibration of the Colpitts oscillator can be achieved. Attached Figure Description

[0019] The above and other features, advantages and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description, wherein:

[0020] Figure 1 The circuit diagrams of three three-point crystal oscillators are shown;

[0021] Figure 2 A schematic diagram of the voltage waveform output from the output pin of a quartz crystal of a Colpitts oscillator under test according to an embodiment of the present disclosure is shown.

[0022] Figure 3 A schematic diagram of the voltage waveform output from the output pin of the quartz crystal of another tested Colpitts oscillator according to an embodiment of the present disclosure is shown.

[0023] Figure 4 A schematic diagram of the voltage waveform output from the output pin of the quartz crystal of another Colpitts oscillator under test according to an embodiment of the present disclosure is shown.

[0024] Figure 5 A schematic diagram of a Colpitts crystal oscillator amplitude detection device according to an embodiment of the present disclosure is shown;

[0025] Figure 6 A schematic diagram of yet another Colpitts crystal oscillator amplitude detection device according to an embodiment of the present disclosure is shown;

[0026] Figure 7 A schematic diagram showing the connection between the amplitude detection device for the Colpitts crystal oscillator under test and the Colpitts oscillator under test according to an embodiment of the present disclosure is shown.

[0027] Figure 8 A schematic diagram of the circuit structure of a bias voltage and offset voltage detection terminal according to an embodiment of the present disclosure is shown.

[0028] Figure 9A schematic flowchart of a Colpitts crystal oscillator amplitude detection method according to an embodiment of the present disclosure is shown;

[0029] Figure 10 A schematic flowchart of a Colpitts crystal oscillator amplitude calibration method according to an embodiment of the present disclosure is shown; and

[0030] In the various figures, the same or corresponding reference numerals indicate the same or corresponding parts. Detailed Implementation

[0031] Embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the accompanying drawings and embodiments of the present disclosure are for illustrative purposes only and are not intended to limit the scope of protection of the present disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0032] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "this embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0033] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, a first state may also be referred to as a second state, and similarly, a second state may also be referred to as a first state. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0034] Generally, calibrating crystal oscillation amplitude requires first reading the crystal's amplitude information. Crystal oscillators are based on the basic three-point oscillator, with Pierce and Colpitts being the most commonly used types. Pierce oscillators connect to the crystal pins via xtal_in (crystal input) and xtal_out (crystal output), and amplitude information can be effectively read using a simple differential amplitude detection circuit. Amplitude calibration is then performed by adjusting the crystal oscillator's operating current. Colpitts crystal oscillators have only one crystal pin connected to the circuit, offering advantages such as no need for additional load capacitors, large oscillation amplitude, and good phase noise. However, the large amplitude detection circuit has always been a challenge in Colpitts circuit design. Furthermore, unlike Pierce oscillators, Colpitts oscillators are highly sensitive to parasitic capacitance introduced by the oscillation circuit, which affects the oscillation amplitude and leads to amplitude detection distortion. Moreover, some methods for obtaining the DC voltage output from the quartz crystal pins of Colpitts oscillators can still become additional sources of interference. Therefore, the Colpitts oscillator requires a large-amplitude detection circuit that does not add any resistive or capacitive load to the oscillator itself, as well as a matching detection and calibration method.

[0035] Furthermore, the various embodiments of this disclosure will be explained in conjunction with specific crystal oscillators, such as... Figure 1 As shown, all crystal oscillators are three-point oscillators, and their specific implementation depends on which node of the transistor is grounded. The leftmost image shows a schematic diagram of a typical three-point crystal oscillator prototype circuit, while the two on the right and middle represent two commonly used structures: the Pierce crystal oscillator and the Colpitts crystal oscillator. The Pierce crystal oscillator typically uses an NMOS transistor with its source grounded, while the Colpitts crystal oscillator typically uses a PMOS transistor with its drain grounded. Furthermore, based on the above explanation, the Colpitts oscillator requires a parasitic-free capacitor, and more importantly, a large-amplitude detection circuit that does not add any resistive or capacitive load to the oscillator itself.

[0036] Furthermore, Colpitts oscillators offer advantages such as large oscillation amplitude, good phase noise, and the use of only one pin. The amplitude stability of a crystal oscillator is crucial for the clock performance stability of a chip and the lifespan and reliability of the crystal. However, for a long time, there has been no good method for reading the amplitude information of Colpitts oscillators. The difficulty lies in two aspects: First, Colpitts oscillators are very sensitive to parasitic capacitance introduced by the oscillation circuit, which affects the oscillation amplitude and leads to amplitude detection distortion; second, such as... Figure 2 and Figure 3As shown, actual oscillator circuits also include diodes for electrostatic discharge (ESD) protection. Generally, the amplitude of a Colpitts oscillator is significantly greater than the diode's forward voltage; therefore, the diode causes clamping distortion in the oscillation waveform, which exacerbates the distortion in amplitude information reading. It should be understood that... Figure 2 In this case, because the amplitude is less than the forward voltage of the diode for electrostatic protection, the voltage value obtained by Vbias + Vdio is not the actual waveform amplitude Vamp. Accordingly, Figure 3 In this case, because the amplitude is greater than the conduction voltage of the diode for electrostatic protection, the voltage value that cannot be obtained by Vbias+Vdio is not the actual waveform amplitude Vamp.

[0037] Furthermore, by examining the distorted waveform, it can be observed that when the trough of the oscillating sine wave is lower than the diode's forward voltage Vdio, for example, as... Figure 3 When the conduction voltage exceeds -0.7, the trough is clamped, and the average voltage of the waveform, i.e., the DC voltage Vdc corresponding to the output pin of the quartz crystal (this DC voltage Vdc is not a measured voltage but is assumed for illustration), will be greater than the bias voltage. This can be manifested as an offset current in the bias resistor, Ioffset = (Vdc - Vbias) / R0. If the bias voltage is actively increased at this time, the distortion caused by the diode clamping of the trough can be avoided. Figure 4 As shown. At this point, it can be observed that if the trough of the waveform is exactly equal to the diode's forward voltage, then the oscillation amplitude is naturally Vamp = Vbias + Vdio, and the offset current Ioffset is 0. It should be understood that although... Figure 2 and Figure 3 The amplitude value Vamp of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator was plotted. However, in actual test circuits, only the bias voltage Vbias and the diode forward voltage Vdio can be measured, and the amplitude value Vamp cannot be measured directly.

[0038] To address at least one of the aforementioned problems, and one or more other potential problems, this disclosure provides a Colpitts crystal oscillator amplitude detection and calibration device. A detailed explanation is provided in conjunction with the accompanying drawings.

[0039] Figure 5A schematic diagram of a Colpitts crystal oscillator amplitude detection device according to an embodiment of the present disclosure is shown. Clearly, the amplitude detection device includes bias voltage and offset voltage detection terminals. These terminals are connected to the output pin of the quartz crystal of the Colpitts oscillator under test via a connecting resistor to detect the offset voltage near the connecting resistor and to adjust the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test. By configuring the Colpitts crystal oscillator amplitude detection device, the offset voltage can be adjusted to gradually increase until it reaches a critical state of constant value. It should be understood that, in some embodiments, the critical state where the offset voltage increases from a small value to a constant value by adjusting the bias voltage can be specifically manifested as follows: adjusting the bias voltage so that the offset voltage changes with the bias voltage; increasing the applied bias voltage so that the offset voltage gradually increases until it just stops changing; and obtaining the amplitude of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test based on the bias voltage value of the critical state and the conduction voltage value of the electrostatic protection diode of the Colpitts oscillator under test. Therefore, the amplitude detection of the Colpitts crystal oscillator can be performed using the Colpitts crystal oscillator amplitude detection device described in the embodiments.

[0040] Furthermore, in other embodiments, such as Figure 6 As shown, the Colpitts crystal oscillator amplitude detection device includes, in addition to, [the following components are included]... Figure 5 In addition to the same bias voltage and offset voltage detection terminals as in the example embodiments, the device may further include: an electrostatic discharge (ESD) protection diode forward voltage acquisition terminal, for connection to a detection circuit of a similar ESD protection diode within the Colpitts oscillator under test, to detect the forward voltage of the ESD protection diode of the same type as the Colpitts oscillator under test, thereby obtaining the forward voltage value of the ESD protection diode of the Colpitts oscillator under test. In other embodiments, the Colpitts crystal oscillator amplitude detection device may further include: a bias current control terminal, for connection to the bias current of the Colpitts oscillator under test, to control the amplitude of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test by controlling the bias current of the Colpitts oscillator under test.

[0041] It should be understood that, in order to further illustrate the various embodiments of this disclosure, Figure 7An exemplary schematic diagram illustrates the connection between a Colpitts crystal oscillator under test and a Colpitts crystal oscillator amplitude detection device. In this illustrated embodiment, the Colpitts oscillator under test includes: a PMOS transistor P0 with its drain grounded, the gate of which is connected to the output pin of a quartz crystal X0, and an electrostatic discharge protection diode D0 disposed between the gate and drain of the PMOS transistor; a connecting resistor R0, which has a first terminal and a second terminal, the first terminal of which is connected to the gate of the PMOS transistor P0, and the second terminal of which is connected to the bias voltage and offset voltage detection terminals; and a bias current, the output of which is connected to the source of the PMOS transistor P0. Further, see... Figure 7 It also includes a capacitor C1 located between the gate and source of the aforementioned PMOS transistor P0, and a capacitor C2 located between the drain and source of the aforementioned PMOS transistor P0. Further, in this illustrated embodiment, the on-state voltage of the electrostatic protection diode D0 obtained by the electrostatic protection diode on-state voltage acquisition terminal is a simulated acquisition method; that is, by detecting the on-state voltage of the electrostatic protection diode D1, which is of the same type as the Colpitts oscillator under test, the on-state voltage value Vdio of the electrostatic protection diode of the Colpitts oscillator under test is obtained. It should also be noted that the bias voltage and offset voltage detection terminals are directly connected to the second end of the connecting resistor R0, which can apply a bias voltage to the output pin of the quartz crystal X0, and can also detect the offset voltage near one end of the connecting resistor (i.e., the second end of the connecting resistor), in conjunction with the offset voltage detected by the bias voltage and offset voltage detection terminals to complete the amplitude detection of the Colpitts oscillator under test. Furthermore, since the forward voltage of a diode is greatly affected by the manufacturing process, a diode D1 with bias current is also introduced. Diode D1 and diode D0 are diodes of the same type or diodes with the same forward voltage, in order to extract the forward voltage Vdio of diode D0.

[0042] Furthermore, in some embodiments, other than Figure 7The circuit is the same, but the bias current of the Colpitts oscillator under test is set to an adjustable bias current, thereby enabling calibration of the voltage waveform amplitude output by the output pin of the quartz crystal. Further, in some embodiments, the Colpitts crystal oscillator amplitude detection device also includes a bias current control terminal, which can be connected to the adjustable bias current of the Colpitts oscillator under test to control the voltage waveform amplitude output by the output pin of the quartz crystal of the Colpitts oscillator under test by controlling the adjustable bias current of the Colpitts oscillator under test; subsequently, amplitude calibration is completed. It should also be understood that in some embodiments, the bias voltage applied to the Colpitts oscillator under test can be set to be connected to the output pin of the quartz crystal of the Colpitts oscillator under test via the aforementioned connecting resistor. It should also be understood that, regarding the bias voltage and offset voltage detection terminals, in order to realize the detection of the offset voltage of the Colpitts oscillator under test and the application of the bias voltage, such as... Figure 8 The diagram illustrates a circuit structure for bias voltage and offset voltage detection. In this example, the bias voltage circuit consists of a buffer circuit composed of N1, N2, P1, and P2. The output bias voltage Vbias is equal to the reference voltage Vref, which is variable. P3 and R1 form a circuit that can indirectly detect the offset current Ioffset. The principle is as follows: When the crystal oscillator waveform is clamped by the diode, a DC current flows into N2 through the bias resistor R0. Since there are constant current sources below N1 and N2, when the current in N2 increases, the current in N1 decreases, and consequently, the current in P1 decreases. Because P3 mirrors the current in P1, the current in P3 decreases, which in turn reduces the output offset voltage Voffset. Furthermore, during amplitude detection, if there is an offset current Ioffset, the reference voltage Vref is actively increased, thereby increasing the bias voltage Vbias and reducing diode clamping distortion. At this time, the offset voltage Voffset will increase. When the bias voltage Vbias is increased and the offset voltage Voffset no longer increases, the offset current Ioffset becomes 0. At this point, the sine wave is no longer distorted by the diode clamping. It should be understood that, for example... Figure 8 As shown, the proposed offset current Ioffset enters from the port marked Vbias, while the offset voltage Voffset marked in the illustrated embodiment is actually the voltage across resistor R1. It should also be understood that... Figure 8 In the example embodiment, the main focus is on whether Voffset changes or remains unchanged, and the trend of change. The specific value of Voffset may vary depending on the specific values ​​assigned to each device in the figure.

[0043] In addition to the aforementioned device, this disclosure also proposes an amplitude detection method for a Colpitts oscillator. The amplitude detection method includes: detecting the offset voltage near one end of the connecting resistor and the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test; adjusting the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test; when the offset voltage decreases as the bias voltage increases, increasing the applied bias voltage so that the offset voltage gradually increases until it stops changing; and obtaining the amplitude value of the voltage waveform output from the output pin of the quartz crystal of the Colpitts oscillator under test based on the bias voltage value at the critical state and the conduction voltage value of the electrostatic protection diode of the Colpitts oscillator under test.

[0044] Furthermore, in some embodiments, the amplitude detection method of the Colpitts oscillator can be as follows: Figure 9 Flowchart. (For example) Figure 9 As shown and referenced Figure 7 Set the initial bias voltage Vbias, read the diode forward voltage Vdio, and read the offset voltage Voffset. Increase the bias voltage Vbias. If the offset voltage Voffset increases at this point, it indicates that there is an offset current in the connecting resistor R0 (or the bias resistor). The oscillation waveform output from the output pin of the quartz crystal of the tested oscillator is clamped and distorted by diode D0. At this point, the bias voltage Vbias needs to be further increased until the offset voltage Voffset no longer increases. If the offset voltage Voffset does not increase when the bias voltage is increased for the first time, it indicates that the bias voltage Vbias is too high and needs to be decreased. When the offset voltage Voffset decreases after decreasing, it indicates that the bias voltage Vbias is now too low. The oscillation waveform output from the output pin of the quartz crystal of the tested oscillator is clamped and distorted by diode D0. At this point, the bias voltage Vbias needs to be returned to the previous level (i.e., a small step back). The amplitude detection process ends, and the amplitude Vamp = Vbias + Vdio is now obtained. Clearly, the offset current Ioffset = 0 at this point. It should also be understood that... Figure 9 In this context, increasing or decreasing Vbias refers to adjusting or changing one level (or, in some scenarios, the smallest step, one bit, or 1 bit).

[0045] Furthermore, this disclosure also provides an amplitude calibration method based on the aforementioned device, with reference to... Figure 10The amplitude calibration method includes: determining the target amplitude value of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test; determining a target bias voltage adjustment value based on the target amplitude value of the voltage waveform, and adjusting the applied bias voltage to the determined target bias voltage adjustment value; adjusting the bias current of the Colpitts oscillator under test so that the amplitude of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test is sufficiently large, i.e., achieving a similar amplitude as shown in the figure. Figure 3 The distorted waveform shown indicates that the offset voltage will change with the aforementioned bias current, for example, increasing and decreasing. Adjusting and decreasing the bias current until the offset voltage stops changing (e.g., gradually increasing until it just stops changing), at the critical point, the waveform will resemble... Figure 4 As shown, the obtained bias current can make the voltage waveform output by the output pin of the quartz crystal of the tested Colpitts oscillator reach the target amplitude value. It should be understood that the oscillation amplitude can be calibrated to a suitable value by adjusting the bias current. Reading the diode forward voltage Vdio, according to the target calibration amplitude value, we can obtain Vbias = Vtag_amp - Vdio. It should be understood that the target amplitude value Vtag_amp is specified and cannot be directly measured. Increasing the bias current of the tested Colpitts oscillator to make the current amplitude value exceed the target amplitude value will inevitably lead to an excessively large amplitude value, resulting in phenomena such as... Figure 3 The distortion shown is adjusted by changing the bias current to achieve the desired result. Figure 4 The critical state shown indicates that the voltage waveform output by the output pin of the quartz crystal of the tested Cobbitz oscillator under the current bias current is the target amplitude value, thus completing the calibration.

[0046] In other embodiments, an electronic device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described above.

[0047] In some other embodiments, a computer-readable storage medium is also provided, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the steps of the method described above.

[0048] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

[0049] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A Colpitts crystal oscillator amplitude detection device, characterized in that, include: The bias voltage and offset voltage detection terminals are used to connect to the output pin of the quartz crystal of the Colpitts oscillator under test via a connecting resistor, so as to detect the offset current output by the output pin of the quartz crystal near the end of the connecting resistor, and to adjust the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test. The Colpitts crystal oscillator amplitude detection device is configured to: The bias voltage is adjusted so that the offset current changes with the change of the bias voltage; Adjust and increase the applied bias voltage so that the offset current gradually becomes just zero; The amplitude of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test is obtained by using the bias voltage value when the offset current gradually changes to just zero and the conduction voltage value of the electrostatic protection diode of the Colpitts oscillator under test.

2. The amplitude detection device according to claim 1, characterized in that, Also includes: The electrostatic discharge protection diode forward voltage acquisition terminal is used to connect with the electrostatic discharge protection diode detection circuit of the same type in the Colpitts oscillator under test, so as to detect the forward voltage of the electrostatic discharge protection diode of the same type in the Colpitts oscillator under test, thereby obtaining the forward voltage value of the electrostatic discharge protection diode of the Colpitts oscillator under test.

3. The amplitude detection device according to claim 1, characterized in that, The tested Colpitts oscillator includes: A PMOS transistor with its drain grounded, wherein the gate of the PMOS transistor is connected to the output pin of a quartz crystal, and an electrostatic protection diode is provided between the gate and the drain of the PMOS transistor. A connecting resistor is provided with a first end and a second end. The first end of the connecting resistor is configured to be connected to the gate of the PMOS transistor, and the second end of the connecting resistor is configured to be connected to the bias voltage and offset voltage detection terminal. The bias current is configured such that its output is connected to the source of the PMOS transistor.

4. The amplitude detection device according to claim 3, characterized in that, The bias current is set to an adjustable bias current.

5. The amplitude detection device according to claim 4, characterized in that, Also includes: The bias current control terminal is used to connect to the adjustable bias current of the Colpitts oscillator under test, so as to control the voltage waveform amplitude output by the output pin of the quartz crystal of the Colpitts oscillator under test by controlling the adjustable bias current of the Colpitts oscillator under test.

6. An amplitude detection method for the apparatus according to any one of claims 1-5, characterized in that, include: The offset current near the end of the connecting resistor and the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test are detected. Adjust the bias voltage applied to the output pin of the quartz crystal of the Colpitts oscillator under test; When the offset current decreases as the bias voltage increases, the applied bias voltage is adjusted to increase so that the offset current gradually decreases to just zero. The amplitude of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test is obtained by using the bias voltage value when the offset current gradually changes to just zero and the conduction voltage value of the electrostatic protection diode of the Colpitts oscillator under test.

7. An amplitude calibration method for the device as described in claim 5, characterized in that, include: Determine the target amplitude value of the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test; The target bias voltage adjustment value is determined based on the target amplitude value of the voltage waveform, and the applied bias voltage is adjusted to the determined target bias voltage adjustment value. Adjust the bias current of the Colpitts oscillator under test so that the voltage waveform output by the output pin of the quartz crystal of the Colpitts oscillator under test has a sufficiently large amplitude so that the voltage waveform reaches a distorted waveform. Adjust and reduce the bias current so that the offset current gradually decreases until it reaches exactly zero.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in claim 6 or 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in claim 6 or 7.

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