Power amplifier circuit load detection method and device

Abstract

The invention discloses a power amplifier circuit load detection method and device. The method comprises the steps that S1, initialization parameters of a power amplifier circuit are set; s2, starting a power amplifier, detecting a current value of an output branch of a power amplifier circuit, and converting the current value into a corresponding voltage feedback value C; s3, judging whether load sudden change occurs or not according to the feedback value C; s4, if no sudden load change occurs, adjusting the frequency of the input driving signal, detecting the change of the voltage feedback value, obtaining the target frequency of the load, locking the driving frequency, and returning to execute the step S3; s5, if the load sudden change occurs, judging whether the current sudden change is the first sudden change after the power amplifier is started or not, and if yes, executing the steps S1-S5 again; and if not, stopping operating the power amplifier. Compared with the prior art, the method provided by the invention is more flexible and accurate to monitor and adjust the load of the power amplifier circuit, the performance and the stability are remarkably improved, and the method is suitable for various power amplifier circuit control scenes.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit control, and particularly to a method and device for detecting the load of a power amplifier circuit. Background Art

[0002] In modern electronic devices and various systems, the power amplifier circuit is a core component, and its main function is to amplify a low-power input signal to a level sufficient to drive loads such as speakers and motors. Especially in high-power and high-performance electronic devices, the efficiency and accuracy of the power amplifier circuit become increasingly important. These circuits usually need to adapt to various load conditions and be able to judge and protect against abnormal situations in a timely manner to maintain their performance and reliability. In this context, accurately monitoring and adjusting the output of the power amplifier circuit becomes an important task. The power amplifier circuit needs to be able to respond quickly and accurately to load changes to ensure the quality and stability of the output signal, especially in situations where the load conditions change frequently, such as in underwater ultrasonic communication, motor control systems, and other high-power applications.

[0003] Existing power amplifier circuit load detection technologies usually rely on traditional current and voltage monitoring. Many power amplifier circuits rely on directly monitoring the values of current or voltage to judge the load situation. Although this method works well in some applications with stable loads, when faced with rapidly changing or relatively complex loads, its reaction speed and accuracy are often insufficient, thus unable to effectively prevent circuit damage caused by load mismatch or sudden events. In addition, the load detection in the existing technology usually does not consider adjusting the output frequency of the power amplifier according to the differences of different loads. This lack of precise frequency tracking design causes the power amplifier circuit to not operate at its optimal efficiency point, thus affecting the overall performance. Since these methods usually lack a fast and flexible response mechanism to load changes, when the load conditions change rapidly (such as when working in different media), the power amplifier circuit may not be able to adjust its operating frequency in a timely manner, resulting in energy waste and performance degradation. Summary of the Invention

[0004] To solve at least one of the technical problems existing in the prior art to a certain extent, an object of the present invention is to provide a method and device for detecting the load of a power amplifier circuit.

[0005] The present invention is realized through the following technical solutions: A method for detecting the load of a power amplifier circuit includes the following steps:

[0006] Step S1: Set the initialization parameters of the power amplifier circuit;

[0007] Step S2: Start the power amplifier, detect the current value of the output branch of the power amplifier circuit, and convert this current value into a corresponding voltage feedback value C;

[0008] Step S3: Judge whether a load mutation occurs according to the feedback value C;

[0009] Step S4: If there is no load mutation, adjust the frequency of the input drive signal, detect the change in the voltage feedback value, obtain the load target frequency, lock the drive frequency, and return to execute Step S3;

[0010] Step S5: If a load mutation occurs, determine whether the current mutation is the first mutation after the power amplifier starts. If so, re-execute Steps S1–S5; if not, stop running the power amplifier.

[0011] Further, the initialization parameters include: the duty ratio of the drive signal, the boost duty ratio BOOST_duty of the power amplifier power supply, the time for re-scanning the drive signal frequency, the threshold voltage V corresponding to the load target frequency freq , the output frequency F of the frequency oscillator in the controller PFRC , the target threshold voltage V during the load operation work , the threshold voltage V during the load operation th , the rated change rate R of the threshold voltage during the load operation th .

[0012] Further, Step S3 includes:

[0013] Real-time detect the voltage feedback value C, perform average algorithm processing according to the voltage feedback value C to obtain the value A;

[0014] Obtain the change rate B of the value A at two moments within a preset time interval;

[0015] If the value A is not within the first preset value range, or the change rate B is not within the second preset value range, it is determined that a load mutation has occurred.

[0016] Further, the average algorithm is arithmetic mean, weighted mean, geometric mean, harmonic mean, Kalman mean, simple moving average, weighted moving average or exponential weighted moving average.

[0017] Further, Step S4 includes:

[0018] If no mutation is detected, perform a frequency scanning power amplifier drive operation on the load by adjusting the frequency of the input drive signal. As the frequency of the input drive signal scans and changes, the voltage feedback value C will change;

[0019] When it is detected that the voltage feedback value C reaches the threshold voltage V freq , use the frequency corresponding to the voltage feedback value C as the load target frequency;

[0020] Lock the load drive frequency according to the load target frequency, keep the power amplifier running, and return to execute Step S3.

[0021] Further, the operation of driving the power amplifier for frequency scanning of the load by adjusting the frequency of the input driving signal includes:

[0022] When the voltage feedback value C is less than the threshold voltage V freq , continuously increase the frequency F PFRC ; when the voltage feedback value C is greater than the threshold voltage V freq , continuously decrease the frequency F PFRC ; update the voltage feedback value C and continuously compare it with the threshold voltage V freq until the voltage feedback value C reaches or approaches the threshold voltage V freq .

[0023] Further, the operation of updating the voltage feedback value C and continuously comparing it with the threshold voltage V freq until the voltage feedback value C reaches or approaches the threshold voltage V freq includes:

[0024] When the voltage feedback value C reaches or approaches the threshold voltage V freq , the counter Count increments. When the counter reaches a preset value, it is considered that the load target frequency tracking is successful, and the frequency F PFRC at this time is used as the load target frequency;

[0025] When the voltage feedback value C exceeds the threshold voltage V freq range, the counter Count is cleared.

[0026] Further, step S4 of the method further includes the following steps:

[0027] Perform boost control on the power amplifier output voltage amplitude until the value A reaches the target value V work , and return to execute step S3.

[0028] Further, the operation of performing boost control on the power amplifier output voltage amplitude until the value A reaches the target value V work , and returning to execute step S3 includes:

[0029] When the value A is less than the target value V work , continuously increase BOOST_duty; when the value A is greater than the target value V work , continuously decrease BOOST_duty; update the value A and continuously compare it with the target value V work until the value A reaches or approaches the target value V work ; return to execute step S3.

[0030] The present invention also provides a load detection device for a power amplifier circuit, including:

[0031] A load detection device for a power amplifier circuit, comprising:

[0032] At least one processor for data processing;

[0033] At least one physical circuit for detecting and controlling the load;

[0034] When the at least one program is executed by the at least one processor, the at least one processor implements the above method.

[0035] The beneficial effects of the present invention are:

[0036] Compared with the prior art, the present invention realizes the accurate tracking of load changes by converting and continuously monitoring the current value of the output branch of the power amplifier circuit. By comparing the processed voltage feedback value with the threshold voltage V th and calculating the change rate and comparing it with the rated change rate R of the threshold voltage th These two methods are combined to comprehensively judge whether the load has a sudden change. If a sudden change is detected, the above steps are re-executed according to the situation of the sudden change or the operation of the power amplifier is stopped. If no sudden change is detected, the frequency of the input drive signal is adjusted for frequency scanning, and frequency locking is performed when the target voltage is reached.

[0037] By comprehensively considering the voltage feedback value and the change rate, the present invention can more accurately detect the real-time change of the load, thereby providing more effective circuit protection. At the same time, by continuously adjusting the frequency of the input drive signal and performing frequency scanning, the present invention can accurately track the target frequency of the load, ensure that the power amplifier operates at the optimal working frequency of the load, and improve the overall efficiency and performance. The present invention not only improves the stability and reliability of the power amplifier circuit, but also improves its operating efficiency under variable load conditions. The present invention also has the characteristics of high precision, high efficiency and easy integration, meeting the requirements of applications such as underwater acoustic communication, sonar, ultrasonic cleaning instrument, ultrasonic atomizer, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following introduces the accompanying drawings related to the technical solutions in the embodiments of the present invention or the prior art. It should be understood that the accompanying drawings below only conveniently and clearly express some embodiments of the technical solutions in the present invention. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 It is a flowchart of a load detection method for a power amplifier circuit in Embodiment 1 of the present invention;

[0040] Figure 2 It is a schematic diagram of the voltage feedback value and the corresponding voltage feedback value change rate in Embodiment 1 of the present invention;

[0041] Figure 3 It is a flowchart for boosting the output voltage amplitude of the power amplifier after successful frequency scanning in Embodiment 1 of the present invention;

[0042] Figure 4 It is a flowchart for the scanning change process of the frequency in Embodiment 1 of the present invention;

[0043] Figure 5 It is a schematic structural diagram of the ultrasonic nebulizer in Embodiment 3 of the present invention;

[0044] Figure 6 It is a schematic structural diagram of the power amplifier circuit 4 of the present invention

[0045] Figure 7 It is a flowchart for the power amplifier circuit load detection method in Embodiment 3 of the present invention when applied to the nebulizer;

[0046] Figure 8 It is a schematic structural diagram of another embodiment of the power amplifier circuit 4 of the present invention;

[0047] Figure 9 It is an application schematic diagram of the power amplifier circuit load detection method in the embodiments of the present invention. Detailed implementation manners

[0048] The embodiments of the present application are described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described by referring to the drawings below are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application. For the step numbers in the following embodiments, they are only set for the convenience of elaboration and explanation, and no limitation is imposed on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0049] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. The singular forms of "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. In addition, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0050] In the description of the present application, it should be understood that regarding the orientation description, for example, the orientation or positional relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0051] In the description of the present application, the meaning of "a number of" is one or more, the meaning of "a plurality of" is two or more. Understandings such as greater than, less than, exceeding, etc. do not include the present number, and understandings such as above, below, within, etc. include the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0052] In the description of the present application, "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0053] Embodiment 1

[0054] Please refer to Figure 1 , this embodiment provides a method for detecting the load of a power amplifier circuit, which specifically includes the following steps:

[0055] Step S1: Set the initialization parameters of the power amplifier circuit.

[0056] Exemplarily, the initialization parameters include: the intermittent ratio of the drive signal, the boost duty cycle BOOST_duty of the power amplifier power supply, the time for rescan of the drive signal frequency, the threshold voltage V corresponding to the target frequency of the load freq , the output frequency F of the frequency oscillator in the controller PFRC , the target threshold voltage V during the operation of the load work , the threshold voltage V during the operation of the load th , the rated change rate R of the threshold voltage during the operation of the load th .

[0057] Among them, the threshold voltage and the rated change rate of the threshold voltage can also be the threshold current, the rated change rate of the threshold current, or the threshold and the change rate of other parameters in the circuit.

[0058] All the above initialization parameters may not be all included in different applications. For example, for a power amplifier without a boost circuit, there is no boost duty cycle BOOST_duty.

[0059] Step S2: Start the power amplifier, detect the current value of the output branch of the power amplifier circuit, and convert this current value into a corresponding voltage feedback value C.

[0060] In this embodiment, the method of converting the current value of the output branch of the power amplifier circuit into the corresponding voltage feedback value C includes but is not limited to using a sampling resistor, using a Hall effect sensor, using a current transformer, etc.

[0061] Step S3: Determine whether a load mutation occurs according to the feedback value C.

[0062] As an implementation manner, algorithm processing is performed according to the voltage feedback value C, and it is determined whether a load mutation occurs by comparing the feedback value threshold voltage, the voltage change rate and the rated change rate of the threshold voltage. The voltage feedback value is detected in real time, average algorithm processing is performed according to the voltage feedback value to obtain the processed value A, and the value A is compared with the threshold voltage V th during the load operation process; at the same time, the change rate B of the value A at two moments within a certain time interval is obtained, and the value B is compared with the rated change rate R th of the threshold voltage during the load operation process. Through these two conditional judgments, as long as one of the conditions reaches the threshold, it is determined that a load mutation has occurred.

[0063] Among them, the average algorithm includes but is not limited to arithmetic mean, weighted mean, geometric mean, harmonic mean, Kalman mean, simple moving average, weighted moving average, exponentially weighted moving average, etc.

[0064] Specifically, comparing the value A with the threshold voltage V th during the load operation process to determine whether the load power consumption situation has changed suddenly further includes:

[0065] The V th includes a first threshold voltage upper limit and a first threshold voltage lower limit.

[0066] When the value A is greater than the first threshold voltage lower limit and less than the first threshold voltage upper limit, it is determined that the load is operating normally; otherwise, it is determined that a load mutation has occurred.

[0067] Among them, the threshold voltage Vth can be either fixed or change with the power supply voltage of the power amplifier.

[0068] Step S4: If no load mutation occurs, adjust the frequency of the input drive signal, detect the change of the voltage feedback value, obtain the load target frequency, lock the drive frequency, and return to execute step S3.

[0069] As an implementation, if no mutation is detected, the frequency of the input drive signal is continuously adjusted to perform a frequency sweep power amplifier drive operation on the load. The current value of the output branch of the power amplifier circuit is converted into a corresponding voltage feedback value C. As the frequency of the input drive signal sweeps and changes, C will change. When it is detected that C reaches or approaches V freq it is regarded that the load target frequency tracking is successful. Subsequently, the load drive frequency is locked, the power amplifier keeps running, and step S3 is continued to be executed.

[0070] Step S5: If a load mutation occurs, determine whether the current mutation is the first mutation after the power amplifier starts. If so, steps S1–S5 are executed again; if not, the power amplifier stops running.

[0071] As an implementation, determining whether the current mutation is the first mutation after the power amplifier starts is to prevent the power amplifier from stopping running erroneously due to accidental data fluctuations or other accidental reasons. The condition for the power amplifier to stop running can be the first detection of a mutation situation, or the detection of a mutation situation any number of times.

[0072] Figure 2 In (a), it is the relationship between the value A obtained by performing an average algorithm process based on the voltage feedback value and time collected in an embodiment of the present application under the working conditions of the power amplifier. Figure 2 In (b), it is the relationship between the change rate B of the value A at two moments within a certain time interval and time. Figure 2 It also marks the threshold voltage V during the working process. th and the rated change rate R of the threshold voltage during the working process of the load. th .

[0073] The working state of the load is first stable. At a certain moment, the voltage feedback value suddenly rises, and the load has a mutation. From Figure 2 in (b), it can be seen that the change rate B of this mutation exceeds the rated change rate R of the threshold voltage. th , and at this time the voltage does not exceed the upper limit V of the first threshold voltage. th1 . Next, the load voltage feedback value slowly decreases until it drops below the lower limit V of the second threshold voltage. th2 Below.

[0074] As Figure 3 shown, in an exemplary embodiment, after the frequency sweep in step S4 is successful, the following steps are further included:

[0075] Step S301: Compare the value A with the target threshold voltage V work during the working process of the load.

[0076] Step S302: If the value A and the target threshold voltage V workThere are significant differences. Boost control is executed. The purpose is to adjust the output power of the power amplifier circuit by adjusting the power supply voltage of the power amplifier circuit until the value A reaches or approaches the target value V work .

[0077] Step S303: After the boost control ends, return to continue executing Step S3.

[0078] The boost control further includes the following steps:

[0079] Step S421: Compare the value A with V work When the current value A is less than V work , continuously increase BOOST_duty, update the value of A and continuously compare it with V work ; otherwise, continuously decrease BOOST_duty, update the value of A and continuously compare it with V work until the value A reaches or approaches the target value V work ; and then continue to execute Step S3.

[0080] As Figure 4 shown, in an exemplary embodiment, the process of the scanning change of the frequency in Step S4 further includes the following steps:

[0081] Step S401: Compare the magnitude relationship between the voltage feedback value C and V freq . If C is close to V freq , the frequency scanning ends. Otherwise, if C is less than V freq , execute Step S402; if C is greater than V freq , execute Step S403;

[0082] Step S402: When C is less than V freq , increase the frequency F PFRC of the adjustable oscillator, update the value of C, and return to Step S401 for judgment.

[0083] Step S403: When C is greater than V freq , decrease the frequency F PFRC of the adjustable oscillator, update the value of C, and return to Step S401 for judgment.

[0084] Among them, the method of frequency adjustment can also be to continuously decrease the frequency starting from the highest value of a frequency, or continuously increase the frequency starting from the lowest value of a frequency until the obtained voltage feedback value C is close to V freq .

[0085] Embodiment 2

[0086] This embodiment is basically the same as Embodiment 1, and the difference is that:

[0087] The comparison of the detected C and V freq also includes the following steps:

[0088] Step S411: When the value of C reaches or approaches V freq the counter Count is incremented. When the counter reaches a certain value, it is considered that the load target frequency tracking is successful, and the F PFRC at this time is the load target frequency;

[0089] Step S412: When the value of C exceeds the range of V freq the counter Count is cleared.

[0090] Embodiment 3

[0091] As Figure 5 and Figure 6 shown, this embodiment demonstrates an application scenario of applying the present invention to an ultrasonic atomizer, including:

[0092] Load 1, used to convert the electrical signal generated by the power amplifier circuit into mechanical power or acoustic wave signal, etc.;

[0093] Load detection circuit 2, used to monitor the operating state of the load and accordingly adjust and control other components of the circuit, including the boost module and the power amplifier circuit;

[0094] Boost module 3, used for loads with a relatively high operating voltage. The boost module is used to raise the power supply voltage to the operating voltage range of the load, and can cooperate with the load detection circuit to control the output current within an appropriate range;

[0095] Power amplifier circuit 4, used to convert data information or control waveforms into high-power waveforms and output them to the load.

[0096] In an exemplary embodiment, the power amplifier circuit 4 includes:

[0097] Oscillator 401, used to generate ultrasonic signal segments that can be finely tuned. Its frequency can be finely tuned by the load detection circuit 2 until it achieves the best match with the load.

[0098] Push-pull amplifier circuit 402, used to amplify the small signal generated by the oscillator, used to drive components such as MOS tubes in the subsequent power amplifier circuit, and at the same time isolate the oscillator operating at a low voltage from the power amplifier circuit operating at a high voltage to prevent the subsequent power amplifier circuit from affecting the previous stage.

[0099] The power amplification circuit 403 is used to further amplify the signal of the push-pull amplification circuit into a high-voltage and large-current signal that can drive the load, and its power supply voltage is provided by the boost module 3. The implementation methods of the power amplification circuit include, but are not limited to, push-pull, half-bridge, full-bridge, inductive boost, transformer boost, etc.

[0100] As Figure 7 shown, in an exemplary embodiment, after the atomizer is powered on, it first performs initialization settings, and then samples the voltage sampling value in the circuit and obtains the voltage feedback value by calculating the average value through moving average. According to the feedback value, the change rate of the feedback value is further obtained, and the working state of the atomizer is judged based on the feedback value and the change rate of the feedback value.

[0101] The no-water detection at startup is performed after a period of time after startup to avoid the power amplification circuit and the feedback network not reaching the stable operation state during the no-water detection at startup.

[0102] The no-water detection includes:

[0103] Judge whether the voltage feedback value is greater than the lower threshold and less than the upper threshold. When the voltage feedback value is greater than the lower threshold and less than the upper threshold, it is determined that there is water; otherwise, it is determined that there is no water.

[0104] Judge whether the change rate of the voltage feedback value is greater than the rated change rate. When the change rate of the voltage feedback value is less than the rated change rate, it is determined that there is water; otherwise, it is determined that there is no water.

[0105] If there is water at startup, frequency tracking is performed. The so-called frequency tracking is to first set a high frequency point, and by judging the voltage feedback value, when the frequency point is not reached, the frequency point is decreased; when it is less than the frequency point, it is increased until the frequency tracking is successful and then the frequency tracking stops.

[0106] If the frequency tracking is successful, the boost module is adjusted. The so-called boost of the boost module is to control the gate duty cycle of the MOS tube of the boost module through the chip to perform boosting. The implementation methods of the boost module circuit include, but are not limited to, BOOST, flyback, forward, SEPIC, charge pump, etc. First, set the voltage value at which the target circuit operates, and then compare the sampled voltage feedback value in the circuit with the voltage value at which the target circuit operates; if the voltage feedback value is lower than the target voltage value, increase the duty cycle of the MOS tube; otherwise, decrease the duty cycle of the MOS tube.

[0107] After the boost is successful, perform a running waterless detection. The running waterless detection is a waterless detection carried out during normal operation. The difference from the startup waterless detection lies in the threshold voltage and the threshold change rate. If waterlessness is detected during operation, it is determined whether it is the first time of waterlessness. If so, the machine is restarted once. This is because the experimental results of this embodiment show that there is a small probability of misjudgment due to various external factors during operation, and there will be no misjudgment if it is determined to be waterless for two consecutive times. If the detected waterlessness this time is not the first time, it is regarded as the atomizer being waterless, and the machine automatically shuts down for protection to prevent the atomizing sheet from being unloaded, damaging the atomizing sheet or causing the temperature of the atomizing sheet to be too high, resulting in safety hazards.

[0108] Embodiment 4

[0109] This embodiment shows an application scenario of applying the present invention to an underwater ultrasonic amplifier. As Figure 8 shown, underwater ultrasonic amplifiers are commonly used in fields such as underwater communication and underwater detection. The power amplifier circuit load detection method proposed by the present invention can be used to monitor whether the ultrasonic transducer is in water and whether there are obstacles near the ultrasonic transducer and other abnormal situations. The signals emitted by underwater ultrasonic amplifiers are usually modulated ultrasonic signals carrying the information contained in the information source. This embodiment is basically the same as Embodiment 3, and the differences are as follows:

[0110] Information source 411, the source of the information carried by the transmitted signal, is usually a low-frequency broadband signal;

[0111] Signal modulation circuit 412, used to modulate the information from the information source into an ultrasonic signal, modulating the low-frequency broadband signal into a high-frequency narrowband signal for convenient transmission.

[0112] Load 1: The load in this embodiment is an ultrasonic transducer, which is used to send ultrasonic signals underwater. Its power is usually greater than that of the atomizer in Embodiment 3. Therefore, the monitoring and protection of this load are particularly important.

[0113] As Figure 9 shown, the power amplifier circuit load detection device 102 described in the present invention is respectively connected to the power amplifier circuit 101 and the transducer 103. The circuit load detection device 102 can control the power amplifier circuit 101 in various ways. The transducer 103 can be various high-power and continuous loads.

[0114] The power amplifier circuit load detection device 102 can be composed of at least one processor and at least one circuit physical object. Among them, the processor is used for the processing of feedback data, and the circuit physical object is used for detecting and controlling the load and is the source of the feedback signal.

[0115] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0116] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those ordinary skilled in the art to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the essence of the content of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for detecting a load of a power amplifier circuit, characterized in that: The following steps are involved: Step S1: setting initialization parameters of the power amplifier circuit; Step S2: starting the power amplifier, detecting the current value of the output branch of the power amplifier circuit, and converting the current value into a corresponding voltage feedback value C; Step S3: judging whether a load mutation occurs according to the feedback value C; Step S4: If no sudden load change occurs, adjust the input drive signal frequency, detect the change of the voltage feedback value, obtain the load target frequency, lock the drive frequency, and return to step S3; Step S5: If a sudden load change occurs, determine whether the current sudden change is the first sudden change after the power amplifier is started. If so, re-execute steps S1-S5; if not, stop running the power amplifier.

2. A power amplifier circuit load detection method according to claim 1, characterized in that: The initialization parameters include: the intermittent ratio of the driving signal, the boost duty ratio of the power amplifier power supply BOOST_duty, the rescanning time of the driving signal frequency, the threshold voltage V corresponding to the load target frequency freq , the frequency oscillator in the controller outputs the frequency F PFRC , target threshold voltage V during load operation work , threshold voltage V during load operation th , Rated change rate of threshold voltage during load operation R th .

3. A power amplifier circuit load detection method according to claim 1, characterized in that: The step S3 comprises: The voltage feedback value C is detected in real time, and an average algorithm is performed according to the voltage feedback value C to obtain a value A; Calculate the rate of change B of value A at two moments within a preset time interval; If the value A is not within the first preset value range, or the change rate B is not within the second preset value range, it is determined that a sudden load change occurs.

4. A power amplifier circuit load detection method according to claim 3, characterized in that: The averaging algorithm is arithmetic mean, weighted mean, geometric mean, harmonic mean, Kalman mean, simple moving average, weighted moving average or exponentially weighted moving average.

5. A power amplifier circuit load detection method according to claim 1, characterized in that: The step S4 comprises: If no sudden change is detected, the frequency of the input drive signal is adjusted to perform a frequency scanning amplifier drive operation on the load. As the frequency of the input drive signal changes, the voltage feedback value C will change; When the voltage feedback value C reaches the threshold voltage V freq , the frequency corresponding to the voltage feedback value C is used as the load target frequency; The load driving frequency is locked according to the load target frequency, the power amplifier is kept running, and the process returns to step S3.

6. A method for detecting a load of a power amplifier circuit according to claim 5, characterized in that: The method of performing a frequency scanning power amplifier driving operation on the load by adjusting the frequency of the input driving signal comprises: When the voltage feedback value C is less than the threshold voltage V freq When the frequency F is continuously increased PFRC ; When the voltage feedback value C is greater than the threshold voltage V freq When the frequency F is continuously reduced PFRC ; Update the voltage feedback value C and continuously compare it with the threshold voltage V freq Comparison is performed until the voltage feedback value C reaches or approaches the threshold voltage V freq .

7. A method for detecting a load of a power amplifier circuit according to claim 6, characterized in that: The updated voltage feedback value C is constantly updated with the threshold voltage V freq Comparison is performed until the voltage feedback value C reaches or approaches the threshold voltage V freq ,include: When the voltage feedback value C reaches or approaches the threshold voltage V freq When the counter reaches the preset value, it is considered that the load target frequency tracking is successful, and the frequency F at this time is PFRC As the load target frequency; When the voltage feedback value C exceeds the threshold voltage V freq When the range is reached, the counter Count is cleared.

8. A method for detecting a load of a power amplifier circuit according to claim 1, characterized in that: The step S4 further comprises the following steps: The output voltage of the power amplifier is boosted until the value A reaches the target value V work , return to execute step S3.

9. A method for detecting a load of a power amplifier circuit according to claim 8, characterized in that: The power amplifier output voltage amplitude is boosted until the value A reaches the target value V work , return to execute step S3, including: When the value A is less than the target value V work When the value A is greater than the target value V work When , BOOST_duty is continuously reduced; the value A is updated and continuously compared with the target value V work Compare until the value A reaches or approaches the target value V work ; Return to execute step S3.

10. A power amplifier circuit load detection device, characterized in that: include: at least one processor for data processing; One less physical circuit for detecting and controlling the load; When the at least one program is executed by the at least one processor, the at least one processor implements the method according to any one of claims 1 to 9.

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