A power amplifier and a control method thereof, and a vehicle audio system

Abstract

The present application discloses a power amplifier and a control method thereof, and a vehicle audio system. The power amplifier includes: at least two first bridge-connected amplifier circuits and at least two second bridge-connected amplifier circuits; the negative pole of the first load of each first bridge-connected amplifier circuit is coupled to the positive pole of the second load of each second bridge-connected amplifier circuit through a gating circuit; when the input signal input to the first signal input terminal of the first bridge-connected amplifier circuit is less than a preset threshold, the gating circuit is turned on, and the first load current of the first bridge-connected amplifier circuit is transmitted to the second load of the second bridge-connected amplifier circuit by the gating circuit. The above scheme can improve the efficiency of the class AB power amplifier.

Description

Technical Field

[0001] The present application relates to the technical field of integrated circuits, and in particular to a power amplifier and a control method thereof, and a vehicle audio system. Background Art

[0002] Class AB power amplifiers are widely used in entertainment systems for their good sound quality and higher efficiency than Class A. The theoretical maximum efficiency of a Class AB power amplifier is only 75%. Long-term playback can easily cause the chip to overheat, resulting in chip performance degradation or even burnout. Therefore, how to improve efficiency becomes an important consideration in power amplifier design.

[0003] Generally, the following solutions can be used to reduce power consumption. Solution 1 is to use a class H power amplifier to reduce power consumption, and solution 2 is to design a class D power amplifier to reduce power consumption. However, for solution 1, the class H power amplifier saves power by adjusting the input power supply, but it needs to adjust the power control chip, which is costly; and for solution 2, the class D power amplifier uses a high-speed clock signal, which is easy to generate interference at the audio end, and the EMI problem is difficult to solve. In addition, the class D power amplifier needs to be configured with an inductor, which is costly. Summary of the invention

[0004] The main technical problem solved by the present application is to provide a power amplifier and a control method thereof, and a vehicle audio system, which can improve the efficiency of a class AB power amplifier.

[0005] In order to solve the above-mentioned problem, the first aspect of the present application provides a power amplifier, which includes: at least two first bridge-connected amplifier circuits and at least two second bridge-connected amplifier circuits; the negative pole of the first load of each of the first bridge-connected amplifier circuits is respectively coupled to the positive pole of the second load of each of the second bridge-connected amplifier circuits through a gating circuit; wherein, when the input signal input to the first signal input terminal of the first bridge-connected amplifier circuit is less than a preset threshold value, the gating circuit is turned on, and the first load current of the first bridge-connected amplifier circuit is transmitted to the second load of the second bridge-connected amplifier circuit by the gating circuit.

[0006] In order to solve the above-mentioned problem, the second aspect of the present application provides a control method for a power amplifier, which is applied to the power amplifier of the above-mentioned first aspect, and the method includes: receiving input signals input by the signal input terminals corresponding to the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit respectively; controlling the selection circuit to disconnect or conduct according to the size of the input signal, so as to disconnect or conduct the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit.

[0007] In order to solve the above problem, the third aspect of the present application provides a vehicle audio system, which includes the power amplifier of the first aspect.

[0008] The beneficial effects of the present invention are as follows: Different from the prior art, the power amplifier of the present application includes at least two first bridge-connected amplifier circuits and at least two second bridge-connected amplifier circuits, and the negative pole of the load of each first bridge-connected amplifier circuit is coupled to the positive pole of the load of each second bridge-connected amplifier circuit through a gating circuit; wherein, when the input signal input to the signal input end of the first bridge-connected amplifier circuit is less than a preset threshold value, the gating circuit is turned on, and the load current of the first bridge-connected amplifier circuit is transmitted to the load of the second bridge-connected amplifier circuit by the gating circuit. By turning on the gating circuit when the input signal input to the signal input end of the first bridge-connected amplifier circuit is less than a preset threshold value, and transmitting the load current of the first bridge-connected amplifier circuit to the load of the second bridge-connected amplifier circuit by the gating circuit, the current can be shared between the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit, so as to improve the efficiency of the bridge-connected amplifier circuit, so that the power amplifier can achieve greater power saving and improve the efficiency of the class AB power amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic structural diagram of an embodiment of a power amplifier of the present application;

[0010] Figure 2 It is a schematic diagram of the structure of a power amplifier in an application scenario of the present application;

[0011] Figure 3 and Figure 4 yes Figure 1 A schematic diagram of a simulation curve of power consumption of a power amplifier and an existing class AB power amplifier;

[0012] Figure 5 It is a flowchart of an embodiment of a method for controlling a power amplifier of the present application. DETAILED DESCRIPTION

[0013] The scheme of the embodiment of the present application is described in detail below in conjunction with the drawings of the specification.

[0014] In the following description, for the purpose of explanation rather than limitation, specific details such as specific system structures, interfaces, and technologies are provided to facilitate a thorough understanding of the present application.

[0015] The terms "system" and "network" are often used interchangeably in this article. The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship. In addition, "many" in this article means two or more than two.

[0016] The present application provides a power amplifier, such as Figure 1 As shown, Figure 1 1 is a schematic diagram of the structure of an embodiment of the power amplifier of the present application. The power amplifier of the present embodiment includes: at least two first bridge-connected amplifier circuits 10 and at least two second bridge-connected amplifier circuits 12; the negative electrode of the first load 100 of each first bridge-connected amplifier circuit 10 is respectively coupled to the positive electrode of the second load 120 of each second bridge-connected amplifier circuit 12 through a gating circuit 111; wherein, when the input signal inputted by the first signal input terminal 101 of the first bridge-connected amplifier circuit 10 is less than a preset threshold value, the gating circuit 111 is turned on, and the load current IL of the first bridge-connected amplifier circuit 10 is transmitted to the second load 120 of the second bridge-connected amplifier circuit 12 through the gating circuit 111.

[0017] In the present embodiment, when the input signal inputted into the first signal input terminal 101 of the first bridge-connected amplifier circuit 10 and the input signal inputted into the second signal input terminal 121 of the second bridge-connected amplifier circuit 12 are both smaller than the preset threshold value, the gating circuit 111 is turned on, and the load current IL of the first bridge-connected amplifier circuit 10 is transmitted to the second load 120 of the second bridge-connected amplifier circuit 12 by the gating circuit 111, and the load current IIL of the second bridge-connected amplifier circuit 12 is also transmitted to the first load 100 of the first bridge-connected amplifier circuit 10, so that the current can be shared between the first bridge-connected amplifier circuit 10 and the second bridge-connected amplifier circuit 12, so as to improve the efficiency of the bridge-connected amplifier circuit, thereby enabling the power amplifier to achieve greater power consumption savings and improve the efficiency of the class AB power amplifier.

[0018] Furthermore, the first bridge-connected amplifier circuit 10 includes a first differential amplifier 102, a second differential amplifier 103 and a first common-mode feedback circuit 104. The positive input terminal of the first differential amplifier 102 and the positive input terminal of the second differential amplifier 103 are respectively connected to the first signal input terminal 101. A first load 100 is connected between the output terminal of the first differential amplifier 102 and the output terminal of the second differential amplifier 103. The input terminal of the first common-mode feedback circuit 104 is used to input a common-mode level. The output terminal of the first common-mode feedback circuit 104 serves as the common-mode circuit input terminal of the first differential amplifier 102 and the second differential amplifier 103 to stabilize the output stage common-mode level of the first differential amplifier 102 and the second differential amplifier 103. level; the second bridge-connected amplifier circuit 12 includes a third differential amplifier 122, a fourth differential amplifier 123 and a second common-mode feedback circuit 124, the positive input terminal of the third differential amplifier 122 and the positive input terminal of the fourth differential amplifier 123 are respectively connected to the second signal input terminal 121, a second load 120 is connected between the output terminal of the third differential amplifier 122 and the output terminal of the fourth differential amplifier 123, the input terminal of the second common-mode feedback circuit 124 is used to input the common-mode level, and the output terminal of the second common-mode feedback circuit 124 is used as the common-mode circuit input terminal of the third differential amplifier 122 and the fourth differential amplifier 123 to stabilize the output stage common-mode level of the third differential amplifier 122 and the fourth differential amplifier 123.

[0019] Furthermore, the first common-mode feedback circuit 104 includes a first common-mode operational amplifier 1040, a first common-mode feedback resistor 1041, and a second common-mode feedback resistor 1042; the output end of the first common-mode operational amplifier 1040 serves as the common-mode circuit input end of the first differential amplifier 102 and the second differential amplifier 103, the two ends of the first common-mode feedback resistor 1041 are respectively connected to the output end of the second differential amplifier 103 and the second input end of the first common-mode operational amplifier 1040, one end of the second common-mode feedback resistor 1042 is connected to the second input end of the first common-mode operational amplifier 1040, and the other end of the second common-mode feedback resistor 1042 is connected to the second input end of the first common-mode operational amplifier 1040. The second common-mode feedback circuit 124 includes a second common-mode operational amplifier 1240, a third common-mode feedback resistor 1241 and a fourth common-mode feedback resistor 1242; the output end of the second common-mode operational amplifier 1240 is used as the common-mode circuit input end of the third differential amplifier 122 and the fourth differential amplifier 123, the two ends of the third common-mode feedback resistor 1241 are respectively connected to the output end of the third differential amplifier 122 and the second input end of the second common-mode operational amplifier 1240, one end of the fourth common-mode feedback resistor 1242 is connected to the second input end of the second common-mode operational amplifier 1240, and the other end of the fourth common-mode feedback resistor 1242 is grounded. It can be understood that when the gating circuit 111 is closed, one end of the first bridge-connected amplifier circuit 10 and the second bridge-connected amplifier circuit 12 are connected together through the gating circuit 111, and are stabilized at the common-mode level through the first common-mode feedback circuit 104 and the second common-mode feedback circuit 124 respectively.

[0020] In one embodiment, the power amplifier further includes a common mode level input circuit 16; the common mode level input circuit 16 is respectively connected to the first input terminal of the first common mode operational amplifier 1040 and the first input terminal of the second common mode operational amplifier 1240. It can be understood that the first input terminal of the first common mode operational amplifier 1040 and the first input terminal of the second common mode operational amplifier 1240 are input with a fixed common mode level through the common mode level input circuit 16, and the second input terminal of the first common mode operational amplifier 1040 obtains the common mode level through the first common mode feedback resistor 1041 and the second common mode feedback resistor 1042, and the second input terminal of the second common mode operational amplifier 1240 obtains the common mode level through the third common mode feedback resistor 1241 and the fourth common mode feedback resistor 1242.

[0021] Specifically, the common-mode level input circuit 16 includes a fixed power supply 160, a first resistor 161, and a second resistor 162, which are electrically connected in sequence. One end of the second resistor 162 away from the first resistor 161 is grounded, and one end of the second resistor 162 close to the first resistor 161 is respectively connected to the first input end of the first common-mode operational amplifier 1040 and the first input end of the second common-mode operational amplifier 1240. The fixed common-mode level is input to the first input end of the first common-mode operational amplifier 1040 and the first input end of the second common-mode operational amplifier 1240 through the coordination of the fixed power supply 160, the first resistor 161, and the second resistor 162. When the power supply voltage of the fixed power supply is VCC, the resistance value of the first resistor DE is R1, and the resistance value of the second resistor DE is R2, then the fixed common-mode level is VCC*R2 / (R1+R2).

[0022] It is understandable that the power amplifier also includes a control circuit (not shown), which is coupled to the selection circuit 111, and is used to control the selection circuit 111 to be disconnected or turned on according to the size of the input signal input by the first signal input terminal 101 and the second signal input terminal 121.

[0023] In one embodiment, the power amplifier is an audio amplifier, and the first load 100 of the first bridge-connected amplifier circuit 10 and the second load 120 of the second bridge-connected amplifier circuit 12 are both speakers. It is understandable that the class AB power amplifier is widely used in the audio field due to the compromise between sound quality and efficiency. In order to improve the sound quality of the class AB power amplifier when a small signal audio is input to achieve an effect close to that of the class A power amplifier, the output transistor of the class AB power amplifier will be in a slightly conductive state when there is no signal. In order to work in a form close to that of the class A power amplifier in a wider power range, the bias current will be adjusted to a very high place, which will cause the efficiency of the power amplifier to drop sharply and generate a lot of heat. The chip is in a high temperature state for a long time, resulting in a sharp drop in chip reliability. In order to solve this problem, the present application introduces a high-efficiency mode (HE mode) into the design of a class AB power amplifier. According to the characteristics of the audio signal, the first bridge-connected amplifier circuit 10 and the second bridge-connected amplifier circuit 12 are connected through a gating circuit 111 when the input is a small audio signal. By utilizing the connection of the gating circuit 111, current can be shared between the first bridge-connected amplifier circuit 10 and the second bridge-connected amplifier circuit 12 to improve the efficiency of the bridge-connected amplifier circuit.

[0024] because Figure 1 There are two first bridge-connected amplifier circuits 10 and two second bridge-connected amplifier circuits 12 in the embodiment, so the output end of the second differential amplifier 103 of each first bridge-connected amplifier circuit 10 and the output end of the third differential amplifier 122 of each second bridge-connected amplifier circuit 12 are connected through a gate circuit 111. Figure 1The two first bridge-connected amplifier circuits 10 are respectively labeled as the first bridge-connected amplifier circuit 10 and the fourth bridge-connected amplifier circuit 14, and the two second bridge-connected amplifier circuits 12 are respectively labeled as the second bridge-connected amplifier circuit 12 and the third bridge-connected amplifier circuit 13. The negative electrode of the first load 100 of the first bridge-connected amplifier circuit 10 is coupled to the positive electrode of the second load 120 of the second bridge-connected amplifier circuit 12 through the first gating circuit 111, and the negative electrode of the first load 100 of the first bridge-connected amplifier circuit 10 is coupled to the positive electrode of the third load 130 of the third bridge-connected amplifier circuit 13 through the second gating circuit 112. The third bridge-connected amplifier circuit 13 comprises a fifth differential amplifier 132, a sixth differential amplifier 133 and a third common-mode feedback circuit 134. The positive input terminal of the fifth differential amplifier 132 and the positive input terminal of the sixth differential amplifier 133 are respectively connected to the third signal input terminal 131. A third load 130 is connected between the output terminal of the fifth differential amplifier 132 and the output terminal of the sixth differential amplifier 133. The input terminal of the third common-mode feedback circuit 134 is used to input a common-mode level. The output terminal of the third common-mode feedback circuit 134 is used as the fifth differential amplifier 132 and the sixth differential amplifier 133. The common-mode circuit input terminal of the fourth bridge-connected amplifier circuit 14 is connected to the common-mode circuit input terminal of the fifth differential amplifier 132 and the sixth differential amplifier 133 to stabilize the common-mode level of the output stages of the fifth differential amplifier 132 and the sixth differential amplifier 133; the negative electrode of the fourth load 140 of the fourth bridge-connected amplifier circuit 14 is coupled to the positive electrode of the third load 130 of the third bridge-connected amplifier circuit 13 through the third selection circuit 113, and the negative electrode of the fourth load 140 of the fourth bridge-connected amplifier circuit 14 is coupled to the positive electrode of the second load 120 of the second bridge-connected amplifier circuit 12 through the fourth selection circuit 114. The fourth bridge-connected amplifier circuit 14 includes a seventh differential amplifier 142, an eighth differential amplifier 143 and a fourth common-mode The feedback circuit 144, the positive input terminal of the seventh differential amplifier 142 and the positive input terminal of the eighth differential amplifier 143 are respectively connected to the fourth signal input terminal 141, and a fourth load 140 is connected between the output terminal of the seventh differential amplifier 142 and the output terminal of the eighth differential amplifier 143. The input terminal of the fourth common-mode feedback circuit 144 is used to input the common-mode level, and the output terminal of the fourth common-mode feedback circuit 144 serves as the common-mode circuit input terminal of the seventh differential amplifier 142 and the eighth differential amplifier 143 to stabilize the common-mode level of the output stages of the seventh differential amplifier 142 and the eighth differential amplifier 143.Specifically, the third common-mode feedback circuit 134 includes a third common-mode operational amplifier 1340, a fifth common-mode feedback resistor 1341 and a sixth common-mode feedback resistor 1342; the output end of the third common-mode operational amplifier 1340 serves as the common-mode circuit input end of the fifth differential amplifier 132 and the sixth differential amplifier 133, the two ends of the fifth common-mode feedback resistor 1341 are respectively connected to the output end of the fifth differential amplifier 132 and the second input end of the third common-mode operational amplifier 1340, one end of the sixth common-mode feedback resistor 1342 is connected to the second input end of the third common-mode operational amplifier 1340, and the other end of the sixth common-mode feedback resistor 1342 is grounded; the fourth common-mode feedback circuit 144 includes a fourth common-mode operational amplifier 1440, a seventh common-mode feedback resistor 1441 and an eighth common-mode feedback resistor 1442; the fourth common-mode operational amplifier 1440 is connected to the fifth common-mode operational amplifier 132 and the sixth common-mode operational amplifier 133; the fifth common-mode feedback resistor 1341 is connected to the fifth common-mode operational amplifier 132 and the sixth common-mode operational amplifier 133; the sixth common-mode feedback resistor 1342 is connected to the sixth common-mode operational amplifier 1342; the fourth common-mode operational amplifier 1440 is connected to the fifth common-mode operational amplifier 132; the sixth common-mode operational amplifier 1340 is connected to the sixth common-mode operational amplifier 134 ... The output end of the common-mode operational amplifier 1440 serves as the common-mode circuit input end of the seventh differential amplifier 142 and the eighth differential amplifier 143, the two ends of the seventh common-mode feedback resistor 1441 are respectively connected to the output end of the eighth differential amplifier 143 and the second input end of the fourth common-mode operational amplifier 1440, one end of the eighth common-mode feedback resistor 1442 is connected to the second input end of the fourth common-mode operational amplifier 1440, and the other end of the eighth common-mode feedback resistor 1442 is grounded; the end of the second resistor 162 in the common-mode level input circuit 16 close to the first resistor 161 is respectively connected to the first input end of the first common-mode operational amplifier 1040, the first input end of the second common-mode operational amplifier 1240, the first input end of the third common-mode operational amplifier 1340 and the first input end of the fourth common-mode operational amplifier 1440. It can be understood that the power amplifier in this embodiment can control the selection of high-efficiency mode between different channels through the first selection circuit 111, the second selection circuit 112, the third selection circuit 113 and the fourth selection circuit 114, so that when the input signals input into each signal input terminal are of different sizes and different phases, the current between the channels can be shared to save current, so as to improve the efficiency of each bridge-connected amplifier circuit, so that the power amplifier can achieve greater power consumption savings and improve the efficiency of the Class AB power amplifier.

[0025] See also Figure 2 , Figure 2It is a schematic diagram of the structure of a power amplifier in an application scenario of the present application. In an application scenario, the input signals inputted by the first signal input terminal 101 of the first bridge-connected amplifier circuit 10, the second signal input terminal 121 of the second bridge-connected amplifier circuit 12 and the fourth signal input terminal 141 of the fourth bridge-connected amplifier circuit 14 are all small signals less than a preset threshold value, while the input signal inputted by the third signal input terminal 131 of the third bridge-connected amplifier circuit 13 is a large signal exceeding the preset threshold value; since the class AB power amplifier can make the output transistor in the on state when the signal is small, but there is a waste of standby power and a loss of power efficiency, therefore, the first gating circuit 111 and the fourth gating circuit 114 can be closed, so that the first bridge-connected amplifier circuit 10, the second bridge-connected amplifier circuit 12 and the fourth bridge-connected amplifier circuit 14 are in a conductive state. The large circuits 14 can share current, so the actual power consumption of the first bridge-connected amplifier circuit 10, the second bridge-connected amplifier circuit 12 and the fourth bridge-connected amplifier circuit 14 to achieve the required output power is less than that of the existing Class AB power amplifier, that is, the efficiency of the first bridge-connected amplifier circuit 10, the second bridge-connected amplifier circuit 12 and the fourth bridge-connected amplifier circuit 14 can be improved. At the same time, since the input signal input by the third signal input terminal 131 is a large signal exceeding the preset threshold, the third bridge-connected amplifier circuit 13 can achieve the required output power through the standard bridge mode. Therefore, it is necessary to disconnect the second selection circuit 112 and the third selection circuit 113 to disconnect the third bridge-connected amplifier circuit 13 from the other bridge-connected amplifier circuits.

[0026] The present application also provides a vehicle audio system, which includes the power amplifier as described above. In one application scenario, Figure 1The power amplifier shown is an audio amplifier in a car audio system. The first load 100, the second load 120, the third load 130 and the fourth load 140 are respectively a left front speaker, a left rear speaker, a right front speaker and a right rear speaker. As the current audio system is improved, the sound source input is usually processed to achieve a stereo effect, which causes the audio signals at each signal input end to be not only inconsistent in size, but also in phase. When a small signal is input to the first signal input terminal 101, the second signal input terminal 121, the third signal input terminal 131 and the fourth signal input terminal 141 of the power amplifier of the present application, the first selection circuit 111, the second selection circuit 112, the third selection circuit 113 and the fourth selection circuit 114 are turned on, so that the 4-bridge high-efficiency mode can be realized; specifically, when the signals input to the first signal input terminal 101, the second signal input terminal 121, the third signal input terminal 131 and the fourth signal input terminal 141 are all lower than the preset threshold value, one end of each of the four channels is connected together and stabilized at the common mode value through the first selection circuit 111, the second selection circuit 112, the third selection circuit 113 and the fourth selection circuit 114, and the other four ends will output a large signal to realize the playback of the load speaker. In addition, when the input signal exceeds the preset threshold value, the input ends of each common mode feedback circuit will be switched at the same time to ensure that the output common mode level is normal. Therefore, the power amplifier can control the conduction and disconnection between different channels through various selection circuits, thereby realizing efficient mode selection between any channels, so that not only can the power consumption be reduced when the signals input to each signal input end are consistent, but also a large power consumption saving can be achieved when the signals input to each signal input end are inconsistent.

[0027] See also Figure 3 and Figure 4 , Figure 3 and Figure 4 yes Figure 1 The power amplifier and the existing AB class power amplifier are shown in the simulation curve diagram. Figure 1 The power amplifier and the existing class AB power amplifier are simulated and verified, where: Figure 3 is a schematic diagram of a curve of output power (abscissa, Pout) and output stage power consumption (ordinate, Pdiss) when the input signals are of the same magnitude and the same phase, La1 is a power consumption curve of the power amplifier of the present application, La2 is a power consumption curve of an existing class AB power amplifier, Figure 4It is a curve diagram of output power (horizontally, Pout) and output stage power consumption (vertically, Pdiss) when the input signals are of the same magnitude and have a phase difference of 90°, Lb1 is a power consumption curve diagram of the power amplifier of the present application, and Lb2 is a power consumption curve diagram of the existing class AB power amplifier. According to the simulation results, it can be found that whether the input signals are of the same magnitude and the same phase, or the input signals are of the same magnitude and different phases, the power consumption consumed by the power amplifier of the present application when outputting the same power is much lower than that of the existing traditional class AB power amplifier.

[0028] The present application also provides a control method for a power amplifier. Figure 5 , Figure 5 1 is a flow chart of an embodiment of a control method for a power amplifier of the present application. In this embodiment, the control method is applied to any of the above-mentioned power amplifiers, and includes the following steps:

[0029] S61: receiving input signals inputted from the signal input terminals corresponding to the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit respectively.

[0030] S62: Controlling the gating circuit to be disconnected or connected according to the magnitude of the input signal, so as to disconnect or connect the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit.

[0031] Specifically, the above-mentioned step S62 specifically includes: determining whether the size of the input signal is greater than a preset threshold; if so, controlling the gating circuit to be disconnected so as to disconnect the first bridge-connected amplifier circuit from the second bridge-connected amplifier circuit; if not, controlling the gating circuit to be turned on so as to transmit the load current of the first bridge-connected amplifier circuit to the load of the second bridge-connected amplifier circuit through the gating circuit.

[0032] In the present embodiment, by respectively receiving input signals inputted by the signal input terminals corresponding to the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit, when the input signal is greater than a preset threshold value, the gating circuit is controlled to be disconnected, at which time the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit will enter the standard bridge mode to achieve the required output power, and when the input signal is a small signal less than the preset threshold value, the gating circuit is controlled to be turned on, and the load current of the first bridge-connected amplifier circuit is transmitted to the load of the second bridge-connected amplifier circuit by the gating circuit, so that the power amplifier can achieve greater power consumption savings and improve the efficiency of the Class AB power amplifier.

[0033] In the several embodiments provided in the present application, it should be understood that the disclosed methods and power amplifiers can be implemented in other ways. For example, the power amplifier implementation described above is only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0034] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0035] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0036] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to perform all or part of the steps of each implementation method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

Claims

1. A power amplifier, characterized in that: The power amplifier comprises: At least two first bridge-connected amplifier circuits and at least two second bridge-connected amplifier circuits, each of the first bridge-connected amplifier circuits includes a first signal input terminal, and each of the second bridge-connected amplifier circuits includes a second signal input terminal; the negative pole of the first load of each of the first bridge-connected amplifier circuits is coupled to the positive pole of the second load of each of the second bridge-connected amplifier circuits through a gating circuit; wherein, when the input signal input to the first signal input terminal of one of the at least two first bridge-connected amplifier circuits and the input signal input to the second signal input terminal of one of the at least two second bridge-connected amplifier circuits are both less than a preset threshold value, the gating circuit is turned on, and the gating circuit enables one of the at least two first bridge-connected amplifier circuits and one of the at least two second bridge-connected amplifier circuits to share the load current.

2. The power amplifier according to claim 1, characterized in that: Each of the first bridge-connected amplifier circuits comprises a first differential amplifier, a second differential amplifier and a first common-mode feedback circuit, wherein the positive input terminal of the first differential amplifier and the positive input terminal of the second differential amplifier are respectively connected to the first signal input terminal, the first load is connected between the output terminal of the first differential amplifier and the output terminal of the second differential amplifier, the negative input terminal of the first differential amplifier and the negative input terminal of the second differential amplifier are respectively connected to the output terminal of the first common-mode feedback circuit, and the input terminal of the first common-mode feedback circuit is used to input a common-mode level; Each of the second bridge-connected amplifier circuits includes a third differential amplifier, a fourth differential amplifier and a second common-mode feedback circuit, the positive input terminal of the third differential amplifier and the positive input terminal of the fourth differential amplifier are respectively connected to the second signal input terminal, the second load is connected between the output terminal of the third differential amplifier and the output terminal of the fourth differential amplifier, the negative input terminal of the third differential amplifier and the negative input terminal of the fourth differential amplifier are respectively connected to the output terminal of the second common-mode feedback circuit, and the input terminal of the second common-mode feedback circuit is used to input a common-mode level.

3. The power amplifier according to claim 2, characterized in that: The first common-mode feedback circuit includes a first common-mode operational amplifier, a first common-mode feedback resistor and a second common-mode feedback resistor; a negative input terminal of the first differential amplifier and a negative input terminal of the second differential amplifier are respectively connected to an output terminal of the first common-mode operational amplifier, two ends of the first common-mode feedback resistor are respectively connected to an output terminal of the second differential amplifier and a second input terminal of the first common-mode operational amplifier, one end of the second common-mode feedback resistor is connected to the second input terminal of the first common-mode operational amplifier, and the other end of the second common-mode feedback resistor is grounded; The second common-mode feedback circuit includes a second common-mode operational amplifier, a third common-mode feedback resistor and a fourth common-mode feedback resistor; a negative input terminal of the third differential amplifier and a negative input terminal of the fourth differential amplifier are respectively connected to the output terminal of the second common-mode operational amplifier, two ends of the third common-mode feedback resistor are respectively connected to the output terminal of the third differential amplifier and the second input terminal of the second common-mode operational amplifier, one end of the fourth common-mode feedback resistor is connected to the second input terminal of the second common-mode operational amplifier, and the other end of the fourth common-mode feedback resistor is grounded.

4. The power amplifier according to claim 3, characterized in that: The power amplifier further comprises a common-mode level input circuit; the common-mode level input circuit is respectively connected to the first input end of the first common-mode operational amplifier and the first input end of the second common-mode operational amplifier.

5. The power amplifier according to claim 4, characterized in that: The common-mode level input circuit includes a fixed power supply, a first resistor and a second resistor electrically connected in sequence, wherein an end of the second resistor away from the first resistor is grounded, and an end of the second resistor close to the first resistor is respectively connected to the first input end of the first common-mode operational amplifier and the first input end of the second common-mode operational amplifier.

6. The power amplifier according to claim 1, characterized in that: The power amplifier also includes a control circuit, which is coupled to the gating circuit and is used to control the gating circuit to be disconnected or turned on according to the magnitude of the input signals inputted by the first signal input terminal and the second signal input terminal.

7. The power amplifier according to claim 1, characterized in that: The power amplifier is an audio amplifier, and the load is a speaker.

8. A method for controlling a power amplifier, characterized in that: Applied to the power amplifier according to any one of claims 1 to 7, the method comprising: Respectively receiving input signals inputted from the signal input ends corresponding to the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit; The gate circuit is controlled to be disconnected or connected according to the size of the input signal, so that the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit are disconnected or connected.

9. The control method of the power amplifier according to claim 8, characterized in that: The step of controlling the gating circuit to be disconnected or connected according to the size of the input signal so as to disconnect or connect the first bridge-connected amplifier circuit and the second bridge-connected amplifier circuit comprises: Determine whether the magnitude of the input signal is greater than a preset threshold; If yes, controlling the gating circuit to be disconnected, so as to disconnect the first bridge-connected amplifier circuit from the second bridge-connected amplifier circuit; If not, the gate circuit is controlled to be turned on, so as to transmit the load current of the first bridge-tied amplifier circuit to the load of the second bridge-tied amplifier circuit via the gate circuit.

10. A car audio system, characterized in that: The in-vehicle audio system comprises the power amplifier according to any one of claims 1 to 7.

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