A circuit for output channel detection and adaptation and a control method thereof

Abstract

The application discloses a circuit for output channel detection and adaptation and a control method thereof, which is suitable for a power amplifier containing single-channel and double-channel modes, and comprises a load interface, a switch module, a microcontroller and a power amplification module. The load interface comprises four terminals of 1, 2, 3 and 4, and in the single-channel mode, the 12 terminals are connected in parallel to one end of a load, and the 34 terminals are connected in parallel to the other end of the load; in the double-channel mode, the 24 terminals are connected to one load, and the 13 terminals are connected to another load. The microcontroller controls the on-off between the control signal and the terminals through the switch module, judges the load connection mode according to different on-off conditions, and controls the power amplification module to adapt. When the power amplifier is connected to an input signal, the power amplifier can automatically judge the single-channel or stereo mode without extra operation, and adjust the settings of the front-stage power amplification circuit according to the mode, so that the power amplifier is convenient to use and damage of the power amplifier body caused by incorrect channel connection or setting is avoided.

Description

Technical Field

[0001] This invention relates to the field of electronic circuits, and more specifically to a circuit and its control method for power amplifier output channel detection and subsequent stage adaptation. Background Technology

[0002] Mono and stereo are the two most common modes in power amplifiers. Mono outputs a mixed audio signal, resulting in a more monotonous sound compared to natural sound; it is a more primitive mode. Stereo, on the other hand, typically outputs two channels simultaneously, producing a more realistic and fuller sound. However, considering factors such as sound quality, power, and energy consumption, mono and stereo still each have their share in the audio market.

[0003] Since mono and stereo have different channels, changing the load without altering the power amplifier circuit can damage the circuit or even the load. Therefore, power amplifiers that can switch between mono and stereo must identify or protect the load.

[0004] Therefore, in order to avoid mismatches between load connection and circuit settings caused by errors, it is necessary to have a circuit that automatically detects and adapts the output channel. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a circuit for output channel detection and adaptation, applicable to power amplifiers with both mono and stereo modes. The circuit includes a load interface, a switching module, a microcontroller, and a power amplifier module. The load interface comprises four terminals: 1, 2, 3, and 4. In mono mode, terminal 12 is connected in parallel to one end of the load, and terminals 3 and 4 are connected in parallel to the other end of the load. In stereo mode, terminal 24 is connected to one channel load, and terminal 13 is connected to the other channel load. The microcontroller controls the switching module to control the connection between the control signal and the terminals, determining the load connection method based on different on / off conditions, thereby controlling the power amplifier module for adaptation.

[0006] The load interface includes four terminals: 1, 2, 3, and 4. In single-channel mode, terminals 1 and 2 are connected in parallel to one end of the load; terminals 3 and 4 are connected in parallel to the other end of the load. In dual-channel mode, terminals 2 and 4 are connected to one channel of the load; terminals 1 and 3 are connected to the other channel of the load.

[0007] The power amplifier module amplifies the input signal and includes a signal processing unit and a power stage. The signal processing unit processes the input signal and has two inputs: one connected to an external input signal, and the other connected to an output terminal of the microcontroller; its output terminal is connected to the power stage. The power stage amplifies the processed signal to the power rail; its input terminal is connected to the output terminal of the signal processing unit, its power supply terminal is connected to an external power source, and its output terminal is connected to the load interface via the switching module.

[0008] The switching module is used to switch signals between the load terminals and the load terminals. It has three sets of modules connected to the signal paths of terminals 2, 3, and 4, respectively. One set mainly includes MOSFETs M1 and M2 and transistor J1. M1 and M2 are identical MOSFETs, with their drains and gates connected together in a back-to-back configuration, connected in series in the signal path of each terminal in the load interface. The collector of J1 is connected to the gate of M1 and M2, its base is connected to one of the microcontroller's outputs, and its emitter is grounded. All three sets of switching modules are connected in the same way.

[0009] The microcontroller is used to detect and logically determine the load status. Its input terminal is connected to terminals 2 of the load interface, and its multiple output terminals are respectively connected to the bases of the transistors in the three sets of switching modules and one input terminal of the signal processing unit. The microcontroller first disconnects all switching devices in the switching module; it then checks if the power stage is connected to a power source. If not, the detection is repeated until a power source is connected. If a power source is connected, an enable signal is sent to the power amplifier module. Next, the switching module connected to load ports 1 and 4 is turned on to generate a half-voltage signal, and a signal is detected at terminal 2. If no signal is generated, it indicates the load is not connected, and the detection is repeated. If a signal is generated, it indicates the load is connected, and the switching module connected to load port 4 is disconnected, and the signal at terminal 2 is checked again. If a signal is generated, the load is in single-channel mode; if no signal is generated, the load is in dual-channel mode. The microcontroller then sends the judgment result to the signal processing unit, which adjusts the signal gain. Finally, all switching devices in the switching module are turned on.

[0010] The present invention also provides a control method for a circuit for output channel detection and adaptation, comprising:

[0011] S1: Disconnect all switching devices of the switching module.

[0012] S2: Detect whether the power stage is connected to a power source. If it is connected to a power source, proceed to step S3; if it is not connected to a power source, repeat step S2.

[0013] S3: Send an enable signal to the power amplifier module.

[0014] S4: The microcontroller turns on the switch module connected to the load ports 1 and 4 to generate a half-voltage signal and detects whether a signal is generated at terminal 2; if a signal is generated, it means that the load is connected and proceeds to step S5; if no signal is generated, it means that the load is not connected and step S4 is repeated.

[0015] S5: The microcontroller disconnects the switch module connected to the load port 4 and checks again whether a signal is generated at terminal 2; if there is a signal, it means that the load is in single-channel mode, and if there is no signal, it means that the load is in dual-channel mode.

[0016] S6: The microcontroller sends the judgment result to the signal processing unit, which then adjusts the signal gain.

[0017] S7: Turn on all the switching devices of the switching module.

[0018] The circuit described in this invention for output channel detection and adaptation can automatically determine whether the power amplifier is in single-channel or dual-channel mode without additional operation when an input signal is connected, and adjust the settings of the pre-amplifier circuit according to the mode. It is convenient to use and effectively avoids damage to the power amplifier body caused by incorrect channel connection or settings.

[0019] To make the above description of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the load interface described in this invention under different modes;

[0022] Figure 2 This is a system block diagram of a circuit for output channel detection and adaptation according to the present invention;

[0023] Figure 3 This is a connection circuit diagram of the switching module described in this invention;

[0024] Number in the picture:

[0025] 10: Load interface; 20: Switching module; 30: Microcontroller; 40: Power amplifier module;

[0026] M1, M2, M3, M4, M5, M6: Same type of MOSFET;

[0027] J1, J2, J3: Transistors. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0029] Please see Figure 1 This diagram illustrates the load interface of the present invention in different modes. In single-channel mode, terminals 1 and 2 are connected, simultaneously connecting one end of load A; terminals 3 and 4 are connected, simultaneously connecting the other end of load A. In dual-channel mode, terminals 2 and 4 are connected to both ends of load B1; terminals 1 and 3 are connected to both ends of load B2. If a signal is received from channel 1, in single-channel mode, terminals 2, 3, and 4 can all detect the signal; in dual-channel mode, only terminal 3 can detect the signal.

[0030] Please see Figure 2 This is a system block diagram of a circuit for output channel detection and adaptation according to the present invention. It includes a load interface 10, a switching module 20, a microcontroller 30, and a power amplifier module 40. The microcontroller 30 controls the switching module 20 to control the connection between the control signal and the terminals, and determines the load connection method based on different on / off conditions, thereby controlling the power amplifier module 40 to perform adaptation.

[0031] Please see Figure 3This is a connection circuit diagram of the switching module described in this invention. M1, M2, and J1 constitute a set of switching modules for controlling terminal 4; M3, M4, and J2 constitute a set of switching modules for controlling terminal 2; M5, M6, and J3 constitute a set of switching modules for controlling terminal 3. M1, M2, M3, M4, M5, and M6 are identical MOS transistors. Taking M1, M2, and J1 as an example, the drains and gates of M1 and M2 are connected together and connected in series in the signal path between the fourth output channel of the power amplifier module and terminal 4. The collector of J1 is connected to the gates of M1 and M2, the emitter is grounded, and the base is connected to the output port 1 of the microcontroller. The three sets of switch modules are connected in the same way. M3, M4 and J2 are connected in series in the signal path between the second output channel of the power amplifier module and terminal 2. The base of J2 is connected to the output port 2 of the microcontroller. M5, M6 and J3 are connected in series in the signal path between the third output channel of the power amplifier module and terminal 3. The base of J3 is connected to the output port 3 of the microcontroller. Terminal 1 is directly connected to the first output channel of the power amplifier module.

[0032] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A circuit for output channel detection and adaptation, characterized in that, Includes load interface, switching module, microcontroller, and power amplifier module; The load interface includes four terminals: 1, 2, 3, and 4. In single-channel mode, terminal 1 and terminal 2 are connected in parallel to one end of the load, and terminal 3 and terminal 4 are connected in parallel to the other end of the load. In dual-channel mode, terminal 2 and terminal 4 are connected to one channel of the load, and terminal 1 and terminal 3 are connected to the other channel of the load. The output of the power amplifier module is connected to the load interface via the switch module; The microcontroller controls the connection and disconnection between the switching module and the terminals, and determines the load connection method according to different connection and disconnection conditions, thereby controlling the power amplifier module to adapt. The power amplifier module includes a signal processing unit and a power stage; the signal processing unit has two inputs, one connected to an external input signal and the other connected to an output terminal of the microcontroller; the output terminal is connected to the power stage. The power stage is used to amplify the processed signal to the power rail. Its input terminal is connected to the output terminal of the signal processing unit, its power supply terminal is connected to an external power supply, and its output terminal is connected to the load interface via the switching module. The switching module has three sets connected to the signal paths of terminals 2, 3, and 4 respectively. One set mainly includes MOSFETs M1 and M2 and transistor J1. M1 and M2 are identical MOSFETs, with their drains and gates connected together in a "back-to-back" configuration, and are connected in series in the signal path of each terminal of the load interface. The collector of J1 is connected to the gate of M1 and M2, its base is connected to one of the outputs of the microcontroller, and its emitter is grounded. The three sets of switching modules are connected in the same way. The microcontroller is used to detect the load condition and make logical judgments. Its input terminal is connected to the two terminals of the load interface, and its multiple output terminals are respectively connected to the base of the transistors in the three sets of the switching module and one input terminal of the signal processing unit. The microcontroller first disconnects all the switching devices in the switching module; The system checks whether the power stage is connected to a power source. If it is not connected, the check is repeated until it is connected. If it is connected, an enable signal is sent to the power amplifier module. Then, the switch module connected to the load interfaces 1 and 4 is turned on to generate a half-voltage signal, and the system checks whether a signal is generated at terminal 2. If there is no signal, it means the load is not connected, and the check is repeated. If there is a signal, it means the load is connected, and the system disconnects the switch module connected to the load interface 4 and checks whether a signal is generated at terminal 2 again. If there is a signal, it means the load is in single-channel mode; if there is no signal, it means the load is in dual-channel mode. The microcontroller then sends the judgment result to the signal processing unit, which adjusts the signal gain; finally, all the switching devices of the switching module are turned on.

2. The control method for the circuit used for output channel detection and adaptation as described in claim 1, characterized in that, include: S1: Disconnect all switching devices in the switching module; S2: Detect whether the power stage is connected to a power source. If it is connected to a power source, proceed to step S3; if it is not connected to a power source, repeat step S2. S3: Send an enable signal to the power amplifier module; S4: The microcontroller turns on the switch module connected to the load interface terminal 1 and terminal 4 to generate a half-voltage signal and detects whether a signal is generated at terminal 2; if there is a signal, it means that the load is connected and proceeds to step S5; if there is no signal, it means that the load is not connected and step S4 is repeated. S5: The microcontroller disconnects the switch module connected to the load interface terminal 4 and checks again whether a signal is generated at terminal 2; if there is a signal, it means that the load is in single-channel mode; if there is no signal, it means that the load is in dual-channel mode. S6: The microcontroller sends the judgment result to the signal processing unit, which then adjusts the signal gain. S7: Turn on all the switching devices of the switching module.

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