Modulation method, circuit, class-d audio amplifier, chip and electronic device

Abstract

This application provides a modulation method, circuit, Class D audio amplifier, chip, and electronic device, relating to the field of electronic circuit technology. The method includes: a common-mode control module acquiring a first quantized signal and a second quantized signal corresponding to the input signal from an integrator, and acquiring a preset threshold from a triangular wave generation module; the common-mode control module determining the category of the input signal based on the relationship between a first voltage value of the first quantized signal and the preset threshold, and the relationship between a second voltage value of the second quantized signal and the preset threshold; and then dynamically adjusting the duty cycle of the output signal of the Class D audio amplifier based on the category of the input signal. This method can avoid signal truncation distortion and minimize power loss when the input signal is a large signal.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and more particularly to a modulation method, circuit, Class D audio amplifier, chip, and electronic device. Background Technology

[0002] Class D audio amplifiers amplify the power of input audio signals using pulse width modulation (PWM), converting the input audio signal (analog audio signal) into a high-frequency PWM switching signal to drive high-power loads. Typically, Class D audio amplifiers are connected to an LC filter, which filters noise and restores the high-frequency PWM signal to its original analog audio signal before delivering it to loads such as speakers.

[0003] For example, Figure 1 A schematic diagram of an LC filter structure is shown according to some embodiments of this application. Figure 1 As shown, the LC filter includes an inductor L and a capacitor C. The input terminals of the LC filter (such as the positive and negative terminals) are used to connect to the high-frequency PWM switching signal output by the Class D audio amplifier, and the output terminal of the LC filter is connected to the speaker a.

[0004] It is understandable that LC filters generate ripple current during operation. When this ripple current is applied to the parasitic resistance of inductor L (i.e., the inherent resistance of inductor L itself), it results in additional power loss. Furthermore, as... Figure 2 As shown, the duty cycle of the high-frequency PWM switching signal output by the Class D audio amplifier is positively correlated with the ripple current; that is, the larger the duty cycle, the larger the peak value of the ripple current.

[0005] Therefore, setting a large duty cycle for the high-frequency PWM switching signal will result in a large peak value of the ripple current in the LC filter, leading to higher power loss in the circuit. However, setting a small duty cycle for the high-frequency PWM switching signal will limit the maximum output power of the Class D audio amplifier, causing truncated distortion in signals with large amplitudes. Summary of the Invention

[0006] This application provides a modulation method, circuit, Class D audio amplifier, chip, and electronic device through several embodiments. The following description covers various aspects, and the embodiments and beneficial effects described herein can be referenced interchangeably.

[0007] In a first aspect, embodiments of this application provide a modulation method applied to a Class D audio amplifier. The Class D audio amplifier includes an integrator, a common-mode control module, and a triangular wave generation module. The method includes: the common-mode control module acquiring a first quantized signal and a second quantized signal corresponding to the input signal from the integrator, and acquiring a preset threshold from the triangular wave generation module; the common-mode control module determining the category of the input signal based on the relationship between a first voltage value of the first quantized signal and the preset threshold, and the relationship between a second voltage value of the second quantized signal and the preset threshold; and the common-mode control module dynamically adjusting the duty cycle of the output signal of the Class D audio amplifier based on the category of the input signal.

[0008] Compared to using a fixed duty cycle, the method provided in this application can dynamically adjust the duty cycle of the output signal of the Class D audio amplifier according to the type of input signal, thereby ensuring the quality of the output signal.

[0009] In one possible implementation of the first aspect, the input signal includes a first analog signal and a second analog signal, wherein the first quantized signal is obtained by integrating the first analog signal with an integrator, and the second quantized signal is obtained by integrating the second analog signal with an integrator.

[0010] In one possible implementation of the first aspect, the first quantized signal and the second quantized signal have a first common-mode voltage value; and the common-mode control module determines the category of the input signal based on the relationship between the first voltage value of the first quantized signal and a preset threshold, and the relationship between the second voltage value of the second quantized signal and the preset threshold, including: when the absolute value of the first difference between the first voltage value and the first common-mode voltage value and the absolute value of the second difference between the second voltage value and the first common-mode voltage value are both less than or equal to the preset threshold, the common-mode control module determines the input signal as a first-type signal; when the absolute value of the first difference or the absolute value of the second difference is greater than the preset threshold, the common-mode control module determines the input signal as a second-type signal; wherein the amplitude of the first-type signal is less than the amplitude of the second-type signal.

[0011] The method provided in this application determines whether an audio signal is a first type of signal (e.g., a small signal) or a second type of signal (e.g., a large signal) by using a first quantization signal and a second quantization signal output by an integrator, thereby improving the accuracy of determining whether an audio signal is a large signal or a small signal.

[0012] In one possible implementation of the first aspect, the common-mode control module dynamically adjusts the duty cycle of the output signal of the Class D audio amplifier based on the type of the input signal, including: when the input signal is a Class I signal, the common-mode control module inputs a common-mode signal with a first common-mode voltage value to an integrator; when the input signal is a Class II signal, the common-mode control module determines a second common-mode voltage value based on the absolute value of a first difference or the absolute value of a second difference, and inputs a common-mode signal with the second common-mode voltage value to the integrator; wherein the absolute value of the first difference is negatively correlated with the second common-mode voltage value, the absolute value of the second difference is negatively correlated with the second common-mode voltage value, the first common-mode voltage value is greater than the second common-mode voltage value, and the first duty cycle corresponding to the first common-mode voltage value is less than the second duty cycle corresponding to the second common-mode voltage value.

[0013] In this method, when the audio signal from the Class D audio amplifier is a small signal, a fixed and relatively small first duty cycle is used to reduce power loss. When the audio signal is a large signal, a second duty cycle larger than the first duty cycle is used to ensure signal quality and avoid truncation distortion.

[0014] Furthermore, the second common-mode voltage value can change linearly with the absolute value of either the first or second difference, causing the second duty cycle to also exhibit a linear trend. Compared to the approach of directly adjusting the second duty cycle to a fixed and large value when the amplitude of the input audio signal is large, this method can minimize power loss while avoiding signal truncation distortion.

[0015] In one possible implementation of the first aspect, the common-mode control module determines a second common-mode voltage value based on the absolute value of a first difference or the absolute value of a second difference, including: if the absolute value of the first difference is greater than a preset threshold, the common-mode control module determines a second common-mode voltage value of the common-mode signal based on the absolute value of the first difference, the preset threshold, and the first common-mode voltage value; if the absolute value of the second difference is greater than the preset threshold, the common-mode control module determines a second common-mode voltage value of the common-mode signal based on the absolute value of the second difference, the preset threshold, and the first common-mode voltage value.

[0016] In one possible implementation of the first aspect, the triangular wave signal of the triangular wave generation module has a peak voltage, and the sum of the first common-mode voltage value, the preset threshold and the first common-mode voltage value is greater than a first multiple of the power supply voltage and less than the peak voltage, the second common-mode voltage value is greater than or equal to the first multiple of the power supply voltage, and the first multiple is greater than 0 and less than 1.

[0017] In one possible implementation of the first aspect, there is a third difference between the sum and the peak voltage. This third difference is used to allow the common-mode control module to adjust the duty cycle before the voltage value of the first quantized signal or the voltage value of the second quantized signal reaches the peak voltage, thereby avoiding input signal truncation distortion.

[0018] It is understandable that the sum of the first threshold and the first common-mode voltage is less than the peak voltage. In this way, the common-mode voltage can be reduced in advance when the audio signal is about to approach the top of the triangular wave, so as to ensure that the audio signal will not be truncated and distorted.

[0019] In one possible implementation of the first aspect, the first duty cycle corresponding to the first common-mode voltage value is 15%, and the second duty cycle corresponding to the second common-mode voltage value is greater than 15% and less than or equal to 50%.

[0020] This application limits the maximum output duty cycle to 50%, thus avoiding limiting the maximum output amplitude and ensuring the output quality of the audio signal.

[0021] Secondly, this application provides a modulation circuit, which includes an integrator, a common-mode control module, and a triangular wave generation module. The first input terminal of the common-mode control module is connected to the first output terminal of the integrator, and the second input terminal of the common-mode control module is connected to the second output terminal of the integrator. The third input terminal of the common-mode control module is connected to the first output terminal of the triangular wave generation module, and the fourth input terminal of the common-mode control module is connected to the second output terminal of the triangular wave generation module.

[0022] In one possible implementation of the second aspect, the fifth input terminal of the common-mode control module is connected to the third output terminal of the triangular wave generation module.

[0023] In one possible implementation of the second aspect, the modulation circuit further includes a first comparator, a second comparator, and a driving module; wherein, the first input terminal of the first comparator is connected to the first output terminal of the integrator, and the second input terminal of the first comparator is connected to the fourth output terminal of the triangular wave generation module; the first input terminal of the second comparator is connected to the second output terminal of the integrator, and the second input terminal of the second comparator is connected to the fourth output terminal of the triangular wave generation module; the first output terminal of the first comparator is connected to the first input terminal of the driving module, and the first output terminal of the second comparator is connected to the second input terminal of the driving module.

[0024] In one possible implementation of the second aspect, the triangular wave generation module includes a reference current generation submodule, a third comparator, and a triangular wave generator; the first terminal of the reference current generation submodule is connected to the first terminal of a first resistor and the first terminal of the triangular wave generator; the second terminal of the first resistor is connected to the first terminal of a second resistor, the second terminal of the second resistor is connected to the first terminal of a third resistor, the second terminal of the third resistor is connected to the first input terminal of the third comparator and the first terminal of a fourth resistor; the second terminal of the fourth resistor is connected to the first terminal of a fifth resistor and the second terminal of the triangular wave generator; the second terminal of the fifth resistor is connected to the drain of a first transistor, the source of the first transistor is grounded, and the gate of the first transistor is connected to the first output terminal of the third comparator.

[0025] In one possible implementation of the second aspect, the common-mode control module includes a reference voltage generation circuit, a first target transistor, a second target transistor, a target amplifier, and a target resistor; a first terminal of the reference voltage generation circuit is connected to the source of the first target transistor, and a second terminal of the reference voltage generation circuit is connected to the gate of the first target transistor; the drain of the first target transistor is connected to the first terminal of the target resistor, the first input terminal of the target amplifier, and the drain of the second target transistor; the source of the second target transistor is connected to the power supply voltage, and the gate of the second target transistor is connected to the first output terminal of the target amplifier.

[0026] Thirdly, embodiments of this application provide a Class D audio amplifier, including the modulation circuit provided by the second aspect and various possible implementations of the second aspect.

[0027] Fourthly, embodiments of this application provide a chip that includes the modulation circuit provided in the second aspect and various possible implementations of the second aspect, or includes the Class D audio amplifier provided in the third aspect.

[0028] Fifthly, embodiments of this application provide an electronic device, including the modulation circuit provided in the second aspect above, or including the Class D audio amplifier provided in the third aspect, or including the chip provided in the fourth aspect. Attached Figure Description

[0029] Figure 1 According to some embodiments of this application, a schematic diagram of an LC filter structure is shown;

[0030] Figure 2 According to some embodiments of this application, a schematic diagram showing the relationship between the duty cycle and ripple current of a high-frequency PWM switching signal output by a Class D audio amplifier is shown.

[0031] Figure 3 According to some embodiments of this application, a schematic diagram of an audio signal exhibiting truncated distortion is shown;

[0032] Figure 4 According to some embodiments of this application, a schematic flowchart of a modulation method is shown;

[0033] Figure 5 According to some embodiments of this application, a schematic diagram showing the relationship between the output duty cycle and the common-mode voltage VCOM of a Class D audio amplifier is shown;

[0034] Figure 6 According to some embodiments of this application, a schematic diagram of the structure of a Class D audio amplifier 100 is shown;

[0035] Figure 7 According to some embodiments of this application, a schematic diagram of the structure of a first triangular wave generating module B1 is shown;

[0036] Figure 8 According to some embodiments of this application, a schematic diagram of the structure of the second triangular wave generation module B1 is shown;

[0037] Figure 9 According to some embodiments of this application, a structural schematic diagram of a common-mode control module E1 is shown;

[0038] Figure 10 According to some embodiments of this application, a schematic diagram is shown showing how the common-mode voltage changes with the voltage value of the quantized signal;

[0039] Figure 11 According to some embodiments of this application, a schematic diagram is shown showing how the output duty cycle changes with the common-mode voltage;

[0040] Figure 12 According to some embodiments of this application, a schematic diagram of the normalization amplitude in the method provided in this application is shown. Detailed Implementation

[0041] The illustrative embodiments of this application include, but are not limited to, modulation methods, circuits, Class D audio amplifiers, chips, and electronic devices.

[0042] The following describes the principle behind the truncated distortion phenomenon that occurs when the duty cycle of a high-frequency PWM switching signal is set to a small value, as mentioned earlier.

[0043] For example, Figure 3 According to some embodiments of this application, a schematic diagram illustrating a truncated distortion phenomenon in an audio signal is shown. For example... Figure 3As shown, the common-mode voltage VCOM of the audio signal IN0 is VCM0, and VCM0 is close to the power supply voltage VDD. The voltage change of the audio signal IN0 between t0 and t1 is shown by the dashed line. However, due to the large value of VCM0 (i.e., a small duty cycle) and the limitation imposed by the power supply voltage VDD, the voltage of the audio signal IN0 between t0 and t1 is forced to cut off at VDD. In other words, the audio signal IN0 experiences losses in the Class D audio amplifier, resulting in signal truncation distortion.

[0044] Therefore, to address the issues of high power loss in the circuit when the duty cycle of a high-frequency PWM switching signal is set too large, and truncation distortion when the duty cycle is set too small for signals with large amplitudes, this application provides a modulation method. This method allows for a smaller duty cycle (e.g., the duty cycle of the output audio signal of a Class D audio amplifier) ​​when the amplitude of the input / output audio signal is small, thus reducing power loss in the circuit. Conversely, it allows for a larger duty cycle when the amplitude of the input / output audio signal is large, thus avoiding truncation distortion of the input signal caused by a small duty cycle.

[0045] Specifically, taking a Class D audio amplifier including an integrator, a common-mode control module, and a triangular wave generation module as an example, the integrator outputs a quantized signal S1 (as an example of a first quantized signal) and a quantized signal S2 (as an example of a second quantized signal) corresponding to the input signal. The quantized signals S1 and S2 may have an initial common-mode voltage VCM1 (as an example of a first common-mode voltage value). Then, the common-mode control module obtains the first and second quantized signals from the integrator and a preset threshold from the triangular wave generation module. Based on the relationship between the first voltage value of the first quantized signal and the preset threshold, and the relationship between the second voltage value of the second quantized signal and the preset threshold, it determines the category of the input signal, for example, whether the input signal belongs to the first or second category (i.e., whether the audio signal is a large signal (signal with a large amplitude) or a small signal (signal with a small amplitude)).

[0046] Next, the common-mode control module dynamically adjusts the duty cycle of the Class D audio amplifier's output signal based on the type of the input signal. For example, when the input signal is a Class I signal (e.g., a small signal), the common-mode control module inputs a common-mode signal with a first common-mode voltage value to the integrator, such that the duty cycle of the Class D audio amplifier's output signal is the smaller first duty cycle corresponding to VCM1. As another example, when the input signal is a Class II signal (e.g., a large signal), the common-mode control module can determine VCM2 (as an example of a second common-mode voltage value) and input a common-mode signal with VCM2 to the integrator, such that the duty cycle of the Class D audio amplifier's output signal is the larger second duty cycle corresponding to VCM2. It can be understood that VCM2 is less than VCM1, and the second duty cycle is greater than the first duty cycle.

[0047] In the method provided in this application, when the audio signal is a small signal, a fixed and relatively small first duty cycle is used to reduce power loss. When the audio signal is a large signal, a second duty cycle larger than the first duty cycle is used to ensure signal quality and avoid signal truncation distortion.

[0048] The modulation method provided in this application will now be described in detail with reference to the accompanying drawings.

[0049] For example, Figure 4 According to some embodiments of this application, a schematic flowchart of a modulation method is shown. The execution entity of each step of the method can be the common-mode control module in a Class D audio amplifier, which will not be described in detail below.

[0050] Specifically, see Figure 4 The modulation may include the following S401-S403.

[0051] S401: The common-mode control module obtains the first quantized signal and the second quantized signal corresponding to the input signal from the integrator, and obtains the preset threshold from the triangular wave generation module.

[0052] It can be understood that the integrator can output a first quantized signal and a second quantized signal corresponding to the input signal. The input signal includes a first analog signal and a second analog signal. The first quantized signal is obtained by integrating the first analog signal, and the second quantized signal is obtained by integrating the second analog signal.

[0053] It is understandable that the connection relationship between the common mode control module, the integrator, and the triangular wave generation module will be described later, and will not be elaborated here.

[0054] S402: The common-mode control module determines the type of the input signal based on the relationship between the first voltage value of the first quantized signal and the preset threshold, and the relationship between the second voltage value of the second quantized signal and the preset threshold.

[0055] It can be understood that the first quantized signal and the second quantized signal have a first common-mode voltage value. If the absolute value of the first difference between the first voltage value and the first common-mode voltage value, and the absolute value of the second difference between the second voltage value and the first common-mode voltage value, are both less than or equal to a preset threshold, then the input signal is determined to be a first-type signal (e.g., a small signal). If the absolute value of the first difference or the absolute value of the second difference is greater than the preset threshold, then the input signal is determined to be a second-type signal (e.g., a large signal).

[0056] Among them, a small signal can refer to a signal with a small amplitude, and a large signal can refer to a signal with a large amplitude, that is, the amplitude of a small signal is smaller than the amplitude of a large signal.

[0057] S403: The common-mode control module dynamically adjusts the duty cycle of the output signal of the Class D audio amplifier based on the type of the input signal.

[0058] For example, when the input signal is a first type signal, a common-mode signal with a first common-mode voltage value is input to the integrator, and the duty cycle of the output signal of the Class D audio amplifier is the first duty cycle. When the input signal is a second type signal, a second common-mode voltage value (the second common-mode voltage value is less than the first common-mode voltage value) is determined based on the absolute value of the first difference or the absolute value of the second difference, and a common-mode signal with the second common-mode voltage value is input to the integrator, and the duty cycle is the second duty cycle, which is greater than the first duty cycle.

[0059] It is understandable that the absolute value of the first difference and the absolute value of the second difference can be the same or different.

[0060] The following section first describes the principle of how different common-mode voltages affect the output duty cycle.

[0061] It can be understood that the relationship between the output duty cycle of a Class D audio amplifier and the common-mode voltage VCOM can be found in the following formula (1).

[0062] D = (VH - V1) avg / V2 avg Formula (1) is: ) / (VH-VL)

[0063] In formula (1), D represents the output duty cycle of a Class D audio amplifier; V1 avg / V2 avg VCOM represents the average voltage of either of the two quantized signals over a fixed time period, which is equal to the common-mode voltage VCOM; VH represents the peak voltage of the triangular wave signal generated by the triangular wave generation mode; and VL represents the valley voltage of the triangular wave signal generated by the triangular wave generation mode.

[0064] For example, Figure 5According to some embodiments of this application, a schematic diagram showing the relationship between the output duty cycle and the common-mode voltage VCOM of a Class D audio amplifier is shown.

[0065] like Figure 5 As shown, the relationship between the output duty cycle and the common-mode voltage VCOM satisfies the above formula (1). For example, if the common-mode voltage VCOM is equal to (VH+VL) / 2, the output duty cycle is 50%; if the common-mode voltage VCOM is greater than (VH+VL) / 2, the output duty cycle is less than 50%.

[0066] According to formula (1) and Figure 5 It can be seen that the output duty cycle of a Class D audio amplifier is negatively correlated with the common-mode voltage VCOM. That is, the larger the common-mode voltage VCOM, the smaller the output duty cycle, and the smaller the common-mode voltage VCOM, the larger the output duty cycle.

[0067] Therefore, in this S403, if the absolute value of the first difference and the absolute value of the second difference are both less than or equal to a preset threshold, the audio signal can be determined to be a small signal. At this time, the common-mode signal with the first common-mode voltage value can continue to be output to the integrator, so that the output duty cycle (e.g., the first duty cycle) is small.

[0068] This application does not limit the principle of setting the magnitude of the first common-mode voltage value. In some embodiments, the magnitude of the first common-mode voltage value can be set based on experience, as long as the first duty cycle corresponding to the first common-mode voltage value is small (e.g., less than the second duty cycle).

[0069] This application does not limit the value of the first duty cycle in its embodiments. For example, the first duty cycle can be 15% or 20%, etc.

[0070] If the absolute value of the first difference or the absolute value of the second difference is greater than a preset threshold, the audio signal can be determined to be a large signal. At this time, the second common-mode voltage value can be determined based on the difference between the first difference and the preset threshold, or based on the difference between the second difference and the preset threshold, and the common-mode signal with the second common-mode voltage value is output to the integrator, so that the output duty cycle (e.g., the second duty cycle) is larger, for example, greater than the first duty cycle.

[0071] For example, the second common-mode voltage value can be determined by the following formula (2).

[0072] VCM2=VCM1-(||V1 / V2-VCM1|-Q|)*L Formula (2)

[0073] In formula (2), V1 represents the first voltage value of the quantized signal S1; V2 represents the second voltage value of the quantized signal S2; Q represents the preset threshold; and L represents the influence coefficient, which can be set according to experience or the actual circuit structure.

[0074] It can be understood that if only the absolute value of the first difference is greater than the preset threshold, then the second common-mode voltage value is determined based on the absolute value of the first difference, the preset threshold, and the first common-mode voltage value. If only the absolute value of the second difference is greater than the preset threshold, then the second common-mode voltage value is determined based on the absolute value of the second difference, the preset threshold, and the first common-mode voltage value.

[0075] If the absolute value of the first difference and the absolute value of the second difference are both greater than a preset threshold, the second common-mode voltage value can be determined based on either the absolute value of the first difference or the absolute value of the second difference, the preset threshold, or the first common-mode voltage value; or, the second common-mode voltage value can be determined based on a voltage value with a larger difference from the preset threshold, the preset threshold, or the first common-mode voltage value.

[0076] According to the above formula (2), if the absolute value of the first difference or the absolute value of the second difference is larger than the absolute value of the difference between the preset threshold, the common mode voltage value is smaller, resulting in a larger second duty cycle.

[0077] Taking a first duty cycle of 15% as an example, in some embodiments, the second duty cycle is greater than 15% and less than or equal to 50%.

[0078] Compared to a fixed duty cycle approach, the method provided in this application can dynamically adjust the duty cycle of the output signal of a Class D audio amplifier based on the type of input signal, thereby ensuring the quality of the output signal.

[0079] The method provided in this application uses a fixed and relatively small first duty cycle when the audio signal of the Class D audio amplifier is a small signal, which can reduce power loss. When the audio signal is a large signal, a second duty cycle larger than the first duty cycle is used, which can both ensure signal quality, avoid signal clipping distortion, and reduce power loss.

[0080] Furthermore, the second common-mode voltage value can change linearly with the absolute value of the first difference, causing the second duty cycle to also exhibit a linear changing trend. Compared to the approach of directly adjusting the second duty cycle to a fixed and large value when the amplitude of the input audio signal is large, this method can minimize power loss while avoiding signal truncation distortion.

[0081] Furthermore, this method determines whether an audio signal is a large or small signal by using the quantization signals S1 and S2 output by the integrator, which can improve the accuracy of determining whether an audio signal is a large or small signal.

[0082] It is understood that the above in this application Figure 4The provided modulation method can be applied to a modulation circuit. In some embodiments, the modulation circuit can be applied to a Class D audio amplifier.

[0083] Therefore, the structure of a Class D audio amplifier capable of performing the modulation method provided in this application will be described below.

[0084] For example, Figure 6 According to some embodiments of this application, a schematic diagram of the structure of a Class D audio amplifier 100 is shown.

[0085] like Figure 6 As shown, the Class D audio amplifier 100 includes an integrator A1, a triangular wave generation module B1, a comparator C1, a comparator D1, an output common-mode control module E1, and a driver module F1.

[0086] like Figure 6 As shown, the integrator A1 includes a first input terminal, a second input terminal, a third input terminal, a fourth input terminal, a first output terminal, and a second output terminal.

[0087] The first input terminal of integrator A1 is connected to the first output terminal of common mode control module E1, the first output terminal of integrator A1 is connected to the first input terminal of common mode control module E1 and the first input terminal of comparator C1, and the second output terminal of integrator A1 is connected to the second input terminal of common mode control module E1 and the first input terminal of comparator D1.

[0088] The second and third input terminals of integrator A1 can be connected to a differential signal generation module (not shown in the figure). For example, the second input terminal of integrator A1 is used to receive the differential signal IN1, and the third input terminal of integrator A1 is used to receive the differential signal IN2. The fourth input terminal of the integrator is used to connect to the power supply voltage VDD.

[0089] Continue as Figure 6 As shown, the triangular wave generation module B1 includes a first output terminal, a second output terminal, a third output terminal, a fourth output terminal, and a first input terminal.

[0090] Specifically, the first output terminal of the triangular wave generation module B1 is connected to the third input terminal of the common mode control module E1, the second output terminal of the triangular wave generation module B1 is connected to the fourth input terminal of the common mode control module E1, and the third output terminal of the triangular wave generation module B1 is connected to the fifth input terminal of the common mode control module E1.

[0091] The fourth output terminal of the triangular wave generation module B1 is connected to the second input terminal of comparator C1 and the second input terminal of comparator D1. The first input terminal of the triangular wave generation module B1 is connected to the power supply voltage PVDD.

[0092] Continue as Figure 6As shown, comparator C1 includes a first input terminal, a second input terminal, a third input terminal, and a first output terminal. The connection method of the first and second input terminals of comparator C1 can be found in the previous description and will not be repeated here.

[0093] The third input terminal of comparator C1 is connected to the power supply voltage VDD. The first output terminal of comparator C1 is connected to the first input terminal of driver module F1.

[0094] Continue as Figure 6 As shown, comparator D1 includes a first input terminal, a second input terminal, a third input terminal, and a first output terminal. The connection method of the first and second input terminals of comparator D1 can be found in the previous description and will not be repeated here.

[0095] The third input terminal of comparator D1 is connected to the power supply voltage VDD. The first output terminal of comparator D1 is connected to the second input terminal of driver module F1.

[0096] Continue as Figure 6 As shown, the common-mode control module E1 includes a first input terminal, a second input terminal, a third input terminal, a fourth input terminal, a fifth input terminal, and a first output terminal. The connection methods of each terminal of the common-mode control module E1 are described above and will not be repeated here.

[0097] Continue as Figure 6 As shown, the driver module F1 includes a first input terminal, a second input terminal, a third input terminal, a first output terminal, and a second output terminal. The connection method of the first and second input terminals of the driver module F1 is described above and will not be repeated here.

[0098] The third input terminal of driver module F1 is connected to the power supply voltage PVDD. The first and second output terminals of driver module F1 can be connected to an LC filter (e.g., Figure 1 (LC filter in the middle) connection.

[0099] Based on the above Figure 6 The function of each module in the Class D audio amplifier 100 is described.

[0100] In some embodiments, integrator A1 can be used to integrate the differential signal to obtain the corresponding quantized signal.

[0101] For example, integrator A1 can obtain differential signals IN1 and IN2 through the first input terminal and the second output terminal respectively, integrate differential signals IN1 and IN2 to obtain quantized signals S1 and S2, and then output quantized signals S1 and S2 through the first output terminal and the second output terminal respectively.

[0102] It is understandable that the differential signal IN1 can be, for example, a positive terminal (P terminal) signal, and the differential signal IN2 can be, for example, a negative terminal (N terminal) signal. Furthermore, the differential signals IN1 and IN2 are analog audio signals, such as sinusoidal audio signals.

[0103] In some embodiments, comparator C1 and comparator D1 can both be used to compare the quantized signal and the triangular wave signal to obtain a high-frequency PWM switching signal.

[0104] For example, comparator C1 can obtain the quantized signal S1 and the triangular wave signal TW through the first input terminal and the second input terminal respectively, compare the quantized signal S1 and the triangular wave signal TW to obtain the high-frequency PWM switching signal P1, and then output the high-frequency PWM switching signal P1 through the first output terminal.

[0105] For example, comparator D1 can obtain the quantized signal S2 and the triangular wave signal TW through the first input terminal and the second input terminal respectively, compare the quantized signal S2 and the triangular wave signal TW to obtain the high-frequency PWM switching signal P2, and then output the high-frequency PWM switching signal P2 through the first output terminal.

[0106] In some embodiments, the drive module F1 can be used to amplify a high-frequency PWM switching signal with a VDD level into a high-frequency PWM switching signal with a PVDD level.

[0107] For example, the drive module F1 can obtain the high-frequency PWM switch signal P1 and the high-frequency PWM switch signal P2 through the first input terminal and the second input terminal respectively, and amplify the signals to obtain the amplified high-frequency PWM switch signal P3 and the high-frequency PWM switch signal P4 respectively. Then, the high-frequency PWM switch signal P3 and the high-frequency PWM switch signal P4 are output through the first output terminal and the second output terminal respectively.

[0108] High-frequency PWM switching signals P3 and P4 can be input to... Figure 1 The LC filter shown is used to filter out noise and restore the high-frequency PWM signal to the original analog audio signal, thereby driving loads such as speakers.

[0109] In some embodiments, the triangular wave generation module B1 can be used to generate and output a high-frequency triangular wave signal TW, a signal having a voltage value DYNAMIC_VH (as an example of the sum of a preset threshold and VCM1), a signal having a voltage value VCM1 (as an example of a first common-mode voltage value), and a signal having a voltage value VDD*m (as an example of a first multiple).

[0110] For example, after the triangular wave generation module B1 generates a triangular wave signal TW, it can output the triangular wave signal TW through the fourth output terminal. In addition, the triangular wave generation module B1 can also output signals with voltage value DYNAMIC_VH, signals with voltage value VCM1, and signals with voltage value VDD*m to the common mode control module E1 through the first output terminal, the second output terminal, and the third output terminal, respectively.

[0111] In some embodiments, the common-mode control module E1 can be used to compare the absolute value of the first voltage value of the quantized signal S1 and the first difference of VCM1 with the magnitude of a preset threshold, and the absolute value of the second voltage value of the quantized signal S2 and the second difference of VCM1 with the magnitude of a preset threshold, and output a common-mode signal with a corresponding common-mode voltage based on the magnitude relationship (i.e., execute the above S402-S403).

[0112] For example, the common-mode control module E1 acquires signals with voltage values ​​DYNAMIC_VH, VCM1, and VDD*m through its third, fourth, and fifth input terminals, respectively. Then, the common-mode control module E1 outputs a common-mode signal with the corresponding common-mode voltage through its first output terminal.

[0113] The following section first describes the principle of how the triangular wave generation module B1 outputs signals with voltage values ​​DYNAMIC_VH, VCM1, and VDD*m, based on the circuit structure of the triangular wave generation module B1.

[0114] For example, Figure 7 According to some embodiments of this application, a schematic diagram of the structure of a first triangular wave generating module B1 is shown.

[0115] like Figure 7 As shown, the triangular wave generation module B1 includes a reference current generation submodule, a triangular wave generator, multiple resistors, and a comparator C2 (as an example of a third comparator).

[0116] The reference current generation submodule generates a reference current IREF1 related to the power supply voltage (e.g., PVDD), which can be a preset current. For example, IREF1 = K1 * PVDD. Here, K1 is a preset scaling parameter determined based on the circuit structure of the reference current generation submodule. The triangular wave generator generates a triangular wave signal, i.e., the TW signal, with a peak voltage of TW_VH and a valley voltage of TW_VL.

[0117] One end of the reference current generation submodule is connected to the first end of the first resistor R1 and the first end of the triangular wave generator. The second end of the first resistor R1 (i.e., Figure 6The first output terminal of the triangular wave generation module B1 is connected to the first terminal of the second resistor R2, and the second terminal of the second resistor R2 (i.e., Figure 6 The second output terminal of the triangular wave generation module B1 is connected to the first terminal of the third resistor R3, and the second terminal of the third resistor R3 is connected to the first input terminal of the comparator C2 and the first terminal of the fourth resistor R4 (i.e., Figure 6 Connect the third output terminal of the triangular wave generation module B1. The voltage at the second input terminal of comparator C2 is 0.5*VDD.

[0118] The second end of the fourth resistor R4 is connected to the first end of the fifth resistor R5, and also to the second end of the triangular wave generator.

[0119] The second terminal of the fifth resistor R5 is connected to the drain of the first metal-oxide-semiconductor field-effect transistor (MOSFET, hereinafter referred to as transistor) M1, the source of the first transistor M1 is grounded, and the gate of the first transistor M1 is connected to the first output terminal of the comparator C2.

[0120] In addition, the third terminal of the triangular wave generator (i.e. Figure 4 The fourth output terminal of the triangular wave generation module B1 is used to output the triangular wave signal TW.

[0121] based on Figure 7 It can be seen that the voltage at the second terminal of the first resistor R1 is DYNAMIC_VH, the voltage at the second terminal of the second resistor R2 is VCM1, the voltage at the first terminal of the first resistor R1 is the peak voltage TW_VH of the triangular wave signal, the voltage at the second terminal of the fourth resistor R4 is the valley voltage TW_VL of the triangular wave signal, and the voltage VC at the first input terminal of comparator C2 is 0.5*VDD.

[0122] Therefore, in Figure 7 In the circuit shown, the expressions for TW_VH and TW_VL can be found in Equations (3) and (4) below, respectively.

[0123] TW_VH=VC+IREF*(R1+R2+R3)=0.5*VDD+K1*PVDD*(R1+R2+R3) Formula (3)

[0124] TW_VL=VC-IREF*R4=0.5*VDD-K1*PVDD*R4 Formula (4)

[0125] The expressions for DYNAMIC_VH and VCM1 can be found in formulas (5) and (6) below, respectively.

[0126] DYNAMIC_VH=VC+IREF*(R2+R3)=0.5*VDD+K1*PVDD*(R2+R3) Formula (5)

[0127] VCM1=VC+IREF*R3=0.5*VDD+K1*PVDD*R3 Formula (6)

[0128] It is understood that, in the embodiments of this application, the triangular wave generation module B1 can output information such as DYNAMIC_VH and VCM1 with specific voltage values ​​to the common mode control module E1 based on the above circuit structure and the resistance values ​​of different resistors.

[0129] In this embodiment, DYNAMIC_VH is preset. In some embodiments, the size of DYNAMIC_VH can be set based on experience. In other embodiments, the size of DYNAMIC_VH can be set based on a voltage threshold (e.g., a first threshold) for determining whether the input audio signal / output audio signal is a large signal or a small signal.

[0130] It can be understood that DYNAMIC_VH is used to determine whether the input audio signal (e.g., differential signal IN1, differential signal IN2) / output audio signal (e.g., high-frequency PWM switching signal P3, high-frequency PWM switching signal P4) is a large signal or a small signal. Therefore, the magnitude of DYNAMIC_VH can be determined based on a voltage threshold (e.g., a first threshold) for determining whether the input audio signal / output audio signal is a large signal or a small signal.

[0131] Taking the case where the output audio signal voltage is greater than the first threshold (large signal) and the output audio signal is less than or equal to the first threshold (small signal) as an example, in this case, a preset threshold can be determined based on the first threshold and the fixed gain K2, and then DYNAMIC_VH can be obtained based on the preset threshold and VCM1. For example, ... Figure 6 As shown, the fixed gain K2 is the gain between the quantized signal S1 / S2 and the high-frequency PWM switching signal P3 / P4.

[0132] Thus, given a first threshold, a preset threshold can be determined based on the first threshold and the fixed gain K. For example, the quotient of the first threshold and the fixed gain K can be used as the preset threshold, and then DYNAMIC_VH can be obtained based on the preset threshold and VCM1.

[0133] For example, the fixed gain K can be determined based on the following formula (7).

[0134] K2 = PVDD / (VH - VCOM) Formula (7)

[0135] In formula (7), K2 represents the fixed gain; PVDD represents the power supply voltage; VH represents the peak voltage of the triangular wave signal TW; and VCOM represents the common-mode voltage of the common-mode signal.

[0136] In some embodiments, the first threshold may be related to PVDD, that is, the relationship between the voltage value of the output audio signal and PVDD is used to determine whether the output audio signal is a large signal or a small signal. For example, the first threshold is equal to n*PVDD, where n is greater than 0 and less than 1.

[0137] In some embodiments, K2 can be made a fixed value by adjusting the size of VH. For example, let VH = VCOM + b * PVDD, then K2 = 1 / b. Here, K2 and b are both constants.

[0138] The following is based on Figure 8 This section introduces the detailed circuit structure of another triangular wave generation module, B1.

[0139] For example, Figure 8 According to some embodiments of this application, a structural schematic diagram of a second triangular wave generation module B1 is shown.

[0140] like Figure 8 As shown, Figure 7 The reference current generation submodule includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a comparator C3, a second transistor M2, a third transistor M3, and a fourth transistor M4.

[0141] Among them, the first end of the sixth resistor R6 is connected to the power supply voltage PVDD, the second end of the sixth resistor R6 is connected to the first end of the seventh resistor R7 and the first input end of the comparator C3, and the second end of the seventh resistor R7 is grounded.

[0142] The second input terminal of comparator C3 is connected to the first terminal of the eighth resistor R8 and the source of the second transistor M2. The first output terminal of comparator C3 is connected to the gate of the second transistor M2. The second terminal of the eighth resistor R8 is grounded.

[0143] The drain of the second transistor M2 is connected to the drain of the third transistor M3, the gate of the third transistor M3, and the gate of the fourth transistor M4. The source of the third transistor M3 is connected to the power supply voltage VDD.

[0144] The source of the fourth transistor M4 is connected to the power supply voltage VDD, and the drain of the fourth transistor M4 is connected to the first terminal of the first resistor R1 and the first input terminal of the comparator C4.

[0145] Continue as Figure 8 As shown, Figure 7The triangular wave generator in the diagram includes a first current source X1, a second current source X2, a first capacitor G1, a comparator C4, a comparator C5, and a comparator C6.

[0146] In this circuit, the first input terminal of comparator C4 is connected to the drain of the fourth transistor M4 and the first terminal of the first resistor R1. The second input terminal of comparator C4 is connected to the second input terminal of comparator C5, the first input terminal of comparator C6, the first terminal of the first capacitor G1, the first terminal of the first switch Z1, and the first terminal of the second current source X2. The second terminal of the first switch Z1 is connected to the first terminal of the first current source X1, and the second terminal of the first current source X1 is connected to the power supply voltage VDD.

[0147] The second terminal of the second current source X2 is connected to the first terminal of the second switch Z2, and the second terminal of the second switch Z2 is grounded. The second terminal of the first capacitor G1 is grounded.

[0148] The first output of comparator C4 is connected to the first input of the first NAND gate T1, the second input of the first NAND gate T1 is connected to the first output of the second NAND gate T2, the first output of the first NAND gate T1 is connected to the first input of the second NAND gate T2, and the second input of the second NAND gate T2 is connected to the first output of comparator C5.

[0149] The first input terminal of comparator C5 is connected to the second terminal of the fourth resistor R4. The second input terminal of comparator C6 is connected to the first output terminal (i.e., the fourth output terminal of the triangular wave generation module B1).

[0150] also, Figure 8 It also includes a ninth resistor R9 and a tenth resistor R10. The first terminal of the ninth resistor R9 is connected to the second input terminal of comparator C2 and the first terminal of the tenth resistor R10. The second terminal of the ninth resistor R9 is connected to the power supply voltage VDD. The second terminal of the tenth resistor R10 is grounded.

[0151] exist Figure 8 In the circuit shown, the expressions for TW_VH and TW_VL can be found in Equations (8) and (9) below, respectively.

[0152] TW_VH=VC+IREF*(R1+R2+R3)=0.5*VDD+PVDD*R2*(R1+R2+R3) / (R3*(R1+R2)) Formula (8)

[0153] TW_VL=VC-IREF*R4=0.5*VDD-PVDD*R2*R4 / (R3*(R1+R2)) Formula (9)

[0154] The expressions for DYNAMIC_VH and VCM1 can be found in formulas (10) and (11) below, respectively.

[0155] DYNAMIC_VH=VC+IREF*(R2+R3)=0.5*VDD+PVDD*R2*(R2+R3) / (R3*(R1+R2)) Formula (10)

[0156] VCM1=VC+IREF*R3=0.5*VDD+PVDD*R2*R3 / (R3*(R1+R2)) Formula (11)

[0157] The following is an introduction Figure 6 The circuit structure of the common-mode control module E1 in the middle.

[0158] For example, Figure 9 According to some embodiments of this application, a schematic diagram of the structure of a common mode control module E1 is shown.

[0159] like Figure 9 As shown, the common-mode control module E1 includes a reference voltage generation circuit, a fifth transistor MOS5 (e.g., NMOS), a sixth transistor MOS6 (e.g., PMOS), an eleventh resistor R11 (as an example of a target resistor), and an amplifier AMP_VCM (as an example of a target amplifier).

[0160] The reference voltage generation circuit is used to output the VREF voltage based on the first voltage value V1 of the first quantization signal S1, the second voltage value V2 of the second quantization signal S2, DYNAMIC_VH, and VCM1.

[0161] The first terminal of the reference voltage generation circuit is connected to the source of the fifth transistor MOS5 (as an example of the first target transistor), the second terminal of the reference voltage generation circuit is used to output the VREF voltage, and the second terminal of the reference voltage generation circuit is connected to the gate of the fifth transistor MOS5.

[0162] The third terminal (i.e. the first input terminal of the common mode control module E1), the fourth terminal (i.e. the second input terminal of the common mode control module E1), and the fifth terminal (i.e. the third input terminal of the common mode control module E1) of the reference voltage generation circuit are used to input the first voltage value V1, the second voltage value V2, and DYNAMIC_VH, respectively.

[0163] The drain of the fifth transistor MOS5 is connected to the first terminal of the eleventh resistor R11, the first input terminal of the amplifier AMP_VCM, and the drain of the sixth transistor MOS6. The second terminal of the eleventh resistor R11 (i.e., the fourth input terminal of the common-mode control module E1) is used for the output voltage VCM1.

[0164] The source of the sixth transistor MOS6 (as an example of the second target transistor) is connected to the power supply voltage, and the gate of the sixth transistor MOS6 is connected to the first output terminal of the amplifier AMP_VCM. The voltage at the second input terminal of the amplifier AMP_VCM is 0.5VDD.

[0165] based on Figure 9 It can be seen that the voltage at the first input terminal of the amplifier AMP_VCM is VCOM.

[0166] It can be understood that if the absolute value of the first difference between the first voltage value V1 and VCM1, and the absolute value of the second difference between the second voltage value V2 and VCM1 are both less than or equal to the difference between DYNAMIC_VH and VCM1 (i.e., the preset threshold), then VREF is 0, the fifth transistor MOS5 is not conducting, IREF2 is very small, approximately 0, and VCOM is approximately equal to VCM1. At this time, the common-mode control module E1 outputs a common-mode signal with VCM1 to the integrator A1, and the duty cycle of the Class D audio amplifier is the first duty cycle, for example, 15%.

[0167] If the absolute value of the first difference or the absolute value of the second difference is greater than the preset threshold, the larger the difference between the absolute value of the first difference or the absolute value of the second difference and the preset difference, the larger VREF and IREF2 will be. Since VCOM = VCM1 - IREF2 * R11, the larger IREF2 is, the smaller VCOM is, and the larger the duty cycle of the Class D audio amplifier will be.

[0168] As VCOM gradually increases to 0.5VDD, the output voltage VG of the amplifier AMP_VCM gradually decreases, causing the sixth transistor MOS6 to turn on. At this point, current no longer flows through the eleventh resistor R11, but instead flows through the sixth transistor MOS6, clamping VCOM at 0.5VDD and preventing it from decreasing below 0.5VDD. When VCOM is 0.5VDD, the duty cycle of the Class D audio amplifier is 50%.

[0169] For example, Figure 10 According to some embodiments of this application, a schematic diagram is shown showing how the common-mode voltage changes with the voltage value of the quantization signal. Figure 11 According to some embodiments of this application, a schematic diagram is shown showing a case where the output duty cycle changes with the common-mode voltage.

[0170] It is understandable that, since the quantized signals S1 and S2 can be sine waves with a 180° phase difference, in this case, the absolute values ​​of the differences between the quantized signals S1 and S2 and the common-mode voltage VCOM at the same moment are the same. Therefore, for ease of illustration, Figure 10 The diagram only shows the change in the voltage value of the quantized signal S1.

[0171] like Figure 10 As shown, VH represents the peak voltage of the triangular wave signal, VL represents the valley voltage of the triangular wave signal, and DYNAMIC_VH (i.e., the sum of the preset threshold and VCM1) is less than VH. At times t2-t3, the quantized signal S1 is in an idle state. It can be seen that the absolute value of the first difference between V1 and VCM1 is 0, which is less than the preset threshold (e.g., the difference between DYNAMIC_VH and VCM1). The common-mode voltage VCOM used is still VCM1. At this time, as... Figure 11 As shown, the first duty cycle corresponding to VCM1 is, for example, 15%.

[0172] At time t3-t4, the quantized signal S1 is a small signal, that is, the absolute value of the first difference between V1 and VCM1 is less than the preset threshold, the common mode voltage VCOM used is still VCM1, and the first duty cycle is still 15%.

[0173] At time t4-t5, the quantized signal S1 is transformed into a large signal, that is, the absolute value of the first difference between V1 and VCM1 is greater than the preset threshold, and V1 gradually increases with time. At this time, the common mode voltage VCOM (e.g., VCM2) gradually decreases based on VCM1, and correspondingly, the second duty cycle gradually increases based on the first duty cycle.

[0174] At time t5-t6, the quantized signal S1 is still a large signal, that is, the absolute value of the first difference between V1 and VCM1 is greater than the preset threshold, and as time increases, V1 gradually decreases. At this time, the common mode voltage VCOM (e.g., VCM2) gradually increases, and correspondingly, the second duty cycle gradually decreases.

[0175] It can be understood that the larger the absolute value of the difference between the first difference and the preset threshold, the larger the second duty cycle. In some embodiments, the second duty cycle is less than or equal to 50%. Figure 11 As shown, the second duty cycle is cut off at 50% between times t7 and t8.

[0176] based on Figure 10 It can be seen that DYNAMIC_VH and VH have a certain difference, Delta_V (as an example of the third difference). This allows the common-mode voltage to be reduced in advance when the audio signal is about to reach the top of the triangular wave, ensuring that the audio signal does not suffer from truncated distortion. Furthermore, based on... Figure 11 As can be seen, the maximum output duty cycle is limited to 50% in this application, which avoids limiting the maximum output amplitude and ensures the output quality of the audio signal.

[0177] It is understandable that the solution provided in this application, while ensuring that both output signals are flipped (i.e., have PWM waveforms), avoids signal truncation distortion and reduces power loss. Compared to some solutions where only one differential signal is flipped (i.e., using a single-sided modulation mode), which leads to a worse common-mode rejection ratio (CMRR) and a reduced ability of the power amplifier to resist common-mode changes, resulting in more severe output signal distortion and reduced linearity of the power amplifier, the solution provided in this application uses a dual-sided modulation mode, meaning that both the P-terminal and N-terminal output signals can be flipped, resulting in higher linearity of the power amplifier.

[0178] Furthermore, unlike some solutions where only one end of the differential output signal has a changing duty cycle while the other has a fixed duty cycle, resulting in a normalized amplitude of 0.8 and preventing the maximum output voltage from reaching the power supply voltage, thus reducing the quality of the output signal, the solution provided in this application allows the duty cycles of the two output signals to change synchronously. Figure 12 As shown, in the solution provided in this application, the maximum output duty cycle is 50% when the signal is large, which allows the normalized amplitude of the output signal to reach 1, that is, the maximum output amplitude of the output signal can reach the power supply voltage, thus ensuring the accuracy of the output signal.

[0179] This application provides a chip, including the aforementioned... Figure 6 The Class D audio amplifier 100 shown is shown.

[0180] This application also provides an electronic device, including the aforementioned... Figure 6 The Class D audio amplifier 100 shown or the aforementioned includes Figure 6 The chip of the Class D audio amplifier 100 shown.

[0181] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0182] All methods and implementations of this application can be implemented in the form of software, magnetic files, firmware, etc.

[0183] Program code can be applied to input instructions to perform the functions described herein and generate output information. The output information can be applied to one or more output devices in a known manner. For the purposes of this application, the processing system includes any system having a processor such as, for example, a Digital Signal Processor (DSP), a microcontroller, an Application-Specific Integrated Circuit (ASIC), or a microprocessor.

[0184] The program code can be implemented using a high-level procedural language or an object-oriented programming language to communicate with the processing system. Assembly language or machine language can also be used when needed. In fact, the mechanisms described in this paper are not limited to any particular programming language. In either case, the language can be a compiled language or an interpreted language.

[0185] One or more aspects of at least one embodiment can be implemented by representational instructions stored on a computer-readable storage medium, the instructions representing various logics in a processor, which, when read by a machine, cause the machine to create logic for performing the techniques described herein. These representations, referred to as “Intellectual Property (IP) cores,” can be stored on a tangible computer-readable storage medium and provided to multiple customers or production facilities for loading into manufacturing machines that actually manufacture the logic or processor.

[0186] In some cases, an instruction translator can be used to translate instructions from a source instruction set to a target instruction set. For example, an instruction translator can transform (e.g., using static binary transformation, including dynamically compiled dynamic binary transformation), morph, emulate, or otherwise translate instructions into one or more other instructions that will be processed by the core. Instruction translators can be implemented in software, hardware, firmware, or a combination thereof. Instruction translators can be on the processor, off-processor, or partially on and partially off-processor.

Claims

1. A modulation method, characterized in that, This is applied to a Class D audio amplifier, which includes an integrator, a common-mode control module, and a triangular wave generation module. The method includes: The common-mode control module obtains the first quantized signal and the second quantized signal corresponding to the input signal from the integrator, and obtains the preset threshold from the triangular wave generation module; The common-mode control module determines the category of the input signal based on the relationship between the first voltage value of the first quantized signal and the preset threshold, and the relationship between the second voltage value of the second quantized signal and the preset threshold. The common-mode control module dynamically adjusts the duty cycle of the output signal of the Class D audio amplifier based on the type of the input signal.

2. The method according to claim 1, characterized in that, The input signal includes a first analog signal and a second analog signal. The first quantized signal is obtained by integrating the first analog signal with the integrator, and the second quantized signal is obtained by integrating the second analog signal with the integrator.

3. The method according to claim 1, characterized in that, The first quantized signal and the second quantized signal have a first common-mode voltage value; and, The common-mode control module determines the category of the input signal based on the relationship between the first voltage value of the first quantized signal and the preset threshold, and the relationship between the second voltage value of the second quantized signal and the preset threshold, including: If the absolute value of the first difference between the first voltage value and the first common-mode voltage value and the absolute value of the second difference between the second voltage value and the first common-mode voltage value are both less than or equal to the preset threshold, the common-mode control module determines that the input signal is a first type of signal. If the absolute value of the first difference or the absolute value of the second difference is greater than the preset threshold, the common-mode control module determines that the input signal is a second type of signal; The amplitude of the first type of signal is smaller than the amplitude of the second type of signal.

4. The method according to claim 3, characterized in that, The common-mode control module dynamically adjusts the duty cycle of the output signal of the Class D audio amplifier based on the type of the input signal, including: When the input signal is the first type of signal, the common-mode control module inputs a common-mode signal having the first common-mode voltage value to the integrator; When the input signal is the second type of signal, the common-mode control module determines the second common-mode voltage value based on the absolute value of the first difference or the absolute value of the second difference, and inputs the common-mode signal with the second common-mode voltage value to the integrator; Wherein, the absolute value of the first difference is negatively correlated with the second common-mode voltage value, the absolute value of the second difference is negatively correlated with the second common-mode voltage value, the first common-mode voltage value is greater than the second common-mode voltage value, and the first duty cycle corresponding to the first common-mode voltage value is less than the second duty cycle corresponding to the second common-mode voltage value.

5. The method according to claim 4, characterized in that, The common-mode control module determines the second common-mode voltage value based on the absolute value of the first difference or the absolute value of the second difference, including: If the absolute value of the first difference is greater than the preset threshold, the common-mode control module determines the second common-mode voltage value of the common-mode signal based on the absolute value of the first difference, the preset threshold, and the first common-mode voltage value. If the absolute value of the second difference is greater than the preset threshold, the common-mode control module determines the second common-mode voltage value of the common-mode signal based on the absolute value of the second difference, the preset threshold, and the first common-mode voltage value.

6. The method according to claim 5, characterized in that, The triangular wave signal generated by the triangular wave generation module has a peak voltage, and, The sum of the first common-mode voltage value, the preset threshold, and the first common-mode voltage value is greater than a first multiple of the power supply voltage and less than the peak voltage. The second common-mode voltage value is greater than or equal to the first multiple of the power supply voltage, where the first multiple is greater than 0 and less than 1.

7. The method according to claim 6, characterized in that, There is a third difference between the sum and the peak voltage. This third difference is used to allow the common-mode control module to adjust the duty cycle before the voltage value of the first quantized signal or the voltage value of the second quantized signal reaches the peak voltage, thereby avoiding truncation distortion of the input signal.

8. The method according to any one of claims 4 to 7, characterized in that, The first duty cycle is 15%, and the second duty cycle is greater than 15% and less than or equal to 50%.

9. A modulation circuit, characterized in that, The modulation circuit includes an integrator, a common-mode control module, and a triangular wave generation module, wherein... The first input terminal of the common-mode control module is connected to the first output terminal of the integrator, and the second input terminal of the common-mode control module is connected to the second output terminal of the integrator. The third input terminal of the common-mode control module is connected to the first output terminal of the triangular wave generation module, and the fourth input terminal of the common-mode control module is connected to the second output terminal of the triangular wave generation module.

10. The modulation circuit according to claim 9, characterized in that, The fifth input terminal of the common-mode control module is connected to the third output terminal of the triangular wave generation module.

11. The modulation circuit according to claim 10, characterized in that, The modulation circuit further includes a first comparator, a second comparator, and a driving module; wherein, The first input terminal of the first comparator is connected to the first output terminal of the integrator, and the second input terminal of the first comparator is connected to the fourth output terminal of the triangular wave generation module. The first input terminal of the second comparator is connected to the second output terminal of the integrator, and the second input terminal of the second comparator is connected to the fourth output terminal of the triangular wave generation module. The first output terminal of the first comparator is connected to the first input terminal of the driver module, and the first output terminal of the second comparator is connected to the second input terminal of the driver module.

12. The modulation circuit according to any one of claims 9 to 11, characterized in that, The triangular wave generation module includes a reference current generation submodule, a third comparator, and a triangular wave generator. The first terminal of the reference current generating submodule is connected to the first terminal of the first resistor and the first terminal of the triangular wave generator. The second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the first input terminal of the third comparator and the first end of the fourth resistor. The second end of the fourth resistor is connected to the first end of the fifth resistor and the second end of the triangular wave generator; The second end of the fifth resistor is connected to the drain of the first transistor, the source of the first transistor is grounded, and the gate of the first transistor is connected to the first output of the third comparator.

13. The modulation circuit according to any one of claims 9 to 11, characterized in that, The common-mode control module includes a reference voltage generation circuit, a first target transistor, a second target transistor, a target amplifier, and a target resistor; The first terminal of the reference voltage generating circuit is connected to the source of the first target transistor, and the second terminal of the reference voltage generating circuit is connected to the gate of the first target transistor. The drain of the first target transistor is connected to the first terminal of the target resistor, the first input terminal of the target amplifier, and the drain of the second target transistor. The source of the second target transistor is connected to the power supply voltage, and the gate of the second target transistor is connected to the first output terminal of the target amplifier.

14. A Class D audio amplifier, characterized in that, Includes the modulation circuit as described in any one of claims 9 to 13.

15. A chip, characterized in that, It includes the modulation circuit as described in any one of claims 9 to 13, or the Class D audio amplifier as described in claim 14.

16. An electronic device, characterized in that, It includes the modulation circuit according to any one of claims 9 to 13, or the Class D audio amplifier according to claim 14, or the chip according to claim 15.

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