Audio power amplification device with audio isolation

Abstract

The utility model discloses an audio power amplification device with audio isolation, and belongs to the technical field of audio signal processing. The first end of the primary side of the audio isolation amplifier is grounded, and the second end of the primary side of the audio isolation amplifier is electrically connected with the output end of the player; the first end of the secondary side of the audio isolation amplifier is electrically connected with the input end INNR of the audio power amplification chip, the second end of the secondary side of the audio isolation amplifier is electrically connected with the input end INPR of the audio power amplification chip, and the power supply input end of the audio power amplification chip is electrically connected with the output end of the power supply module; the output end of the audio power amplification chip is electrically connected with the first input end of the loudspeaker, and the output end of the audio power amplification chip is electrically connected with the second input end of the loudspeaker. The audio power amplification device with the audio isolation function solves the problems that an existing audio power amplifier is complex in wiring between devices, and the use feeling of a user is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of audio signal processing, in particular to an audio power amplifier with audio isolation. Background Art

[0002] An audio power amplifier is a device that reconstructs the input audio signal on the output element that produces the sound. In the existing solution, Texas Instruments' TPA3118 is generally used as an audio power amplifier, and the output of the audio power amplifier is connected to the speaker; and if the input of the audio power amplifier is directly connected to the player of the audio signal input, the player may be damaged due to the backflow of current in the circuit. Therefore, in the existing solution, an external audio isolator is required between the player and the audio power amplifier. Since the audio isolator is external to the audio power amplifier, and the audio isolator and the audio power amplifier need to be connected and locked with screw terminals, the wiring between the devices is complicated, which reduces the user experience. Utility Model Content

[0003] In order to overcome the defects of the prior art, the utility model provides an audio power amplifier with audio isolation to solve the above problems.

[0004] The technical solution adopted by the utility model to solve the technical problem is: an audio power amplifier device with audio isolation, including a power module and an audio power amplifier chip U1 and an audio isolation amplifier U2 welded on the same circuit board;

[0005] The first end of the primary side of the audio isolation amplifier U2 is grounded, and the second end of the primary side of the audio isolation amplifier U2 is electrically connected to the output end of an external player; the first end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input end INNR of the audio power amplifier chip U1, the second end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input end INPR of the audio power amplifier chip U1, and the power input end PVCC of the audio power amplifier chip U1 is electrically connected to the output end of the power module; the output end OUTNR of the audio power amplifier chip U1 is electrically connected to the first input end of an external speaker, and the output end OUTNL of the audio power amplifier chip U1 is electrically connected to the second input end of the external speaker.

[0006] It is worth noting that the power module includes a Schottky diode D1, a Schottky diode D2, a Schottky diode D3, a Schottky diode D4, a Schottky diode D5, a Schottky diode D6 and a Schottky diode D7 connected in series in sequence; the anode of the Schottky diode D1 serves as the anode of the input end of the power module, the cathode of the input end of the power module is grounded, and the cathode of the Schottky diode D7 serves as the output end of the power module.

[0007] Optionally, the power module also includes capacitors C2, C3, C4, C5, C6, C7, C8 and C9 connected in parallel; the first end of the capacitor C2 is electrically connected to the cathode of the Schottky diode D7, and the second end of the capacitor C2 is grounded.

[0008] Preferably, a capacitor C11 is provided at the second end of the primary side of the audio isolation amplifier U2, so that the second end of the primary side of the audio isolation amplifier U2 is electrically connected to the output end of the external player through the capacitor C11.

[0009] Specifically, a capacitor C14 is provided at the first end of the secondary side of the audio isolation amplifier U2, and the first end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input terminal INNR of the audio power amplifier chip U1 through the capacitor C14; a capacitor C15 is provided at the first end of the secondary side of the audio isolation amplifier U2, and the second end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input terminal INPR of the audio power amplifier chip U1 through the capacitor C15.

[0010] Optionally, it further includes an output processing module, which is arranged between the audio power amplifier chip U1 and an external speaker;

[0011] The output processing module includes an inductor L1, an inductor L2, a capacitor C18, a resistor R9, a capacitor C19, a capacitor C20 and a capacitor C21; the output end OUTNL of the audio power amplifier chip U1 is electrically connected to the first end of the inductor L1 and the first end of the capacitor C18, respectively, and the second end of the inductor L1 is electrically connected to the first end of the capacitor C19, the first end of the capacitor C20 and the second input end of the external speaker, respectively; the output end OUTNR of the audio power amplifier chip U1 is electrically connected to the first end of the inductor L2 and the first end of the resistor R9, respectively, and the second end of the inductor L2 is electrically connected to the second end of the capacitor C19, the first end of the capacitor C21 and the first input end of the external speaker, respectively; the second end of the capacitor C18 is electrically connected to the second end of the resistor R9, and the second end of the capacitor C20 is connected in parallel with the second end of the capacitor C21 and then grounded.

[0012] The beneficial effect of the utility model is that in the audio power amplifier device with audio isolation, after the audio power amplifier chip U1 and the audio isolation amplifier U2 are soldered on the same circuit board, the user only needs to connect the player to the second end of the primary side of the audio isolation amplifier U2 and connect the speaker to the output terminal OUTNR and the output terminal OUTNL of the audio power amplifier chip U1 to complete the wiring, which simplifies the wiring between devices and improves the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A circuit diagram of an audio power amplifier with audio isolation in one embodiment of the utility model;

[0014] Figure 2 A circuit diagram of a power module in one embodiment of the utility model;

[0015] Figure 3 This is a port distribution diagram of the audio power amplifier chip U1 in one embodiment of the utility model. DETAILED DESCRIPTION

[0016] The specific implementation methods of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these implementation methods is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each implementation method of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0017] like Figure 1-3 As shown, an audio power amplifier device with audio isolation includes a power module and an audio power amplifier chip U1 and an audio isolation amplifier U2 welded on the same circuit board; the model of the audio power amplifier chip U1 is CS8673; the audio isolation amplifier U2 is an isolated audio transformer;

[0018] The first end of the primary side of the audio isolation amplifier U2 is grounded through a resistor R4, which effectively enhances the anti-interference ability. The second end of the primary side of the audio isolation amplifier U2 is electrically connected to the output end of an external player (external player terminal CN2); the first end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input end INNR (port 6) of the audio power amplifier chip U1 by welding, the second end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input end INPR (port 7) of the audio power amplifier chip U1 by welding, and the power input end PVCC (port 1 and port 8) of the audio power amplifier chip U1 is electrically connected to the output end of the power module; the output end OUTNR (port 12) of the audio power amplifier chip U1 is electrically connected to the first input end of the external speaker, and the output end OUTNL (port 13) of the audio power amplifier chip U1 is electrically connected to the second input end of the external speaker (terminal CN3).

[0019] In the audio power amplifier device with audio isolation, by soldering the audio power amplifier chip U1 and the audio isolation amplifier U2 on the same circuit board, the user only needs to connect the player to the second end of the primary side of the audio isolation amplifier U2 and connect the speaker to the output terminal OUTNR and the output terminal OUTNL of the audio power amplifier chip U1 to complete the wiring, which simplifies the wiring between devices and improves the user experience.

[0020] The specific principle is that after the audio signal of the player passes through the audio isolation amplifier U2, an audio signal corresponding to its primary side is formed on the secondary side of the audio isolation amplifier U2, and then input into the audio power amplifier chip U1 for power amplification, and then output to the speaker for audio playback.

[0021] This solution eliminates the connection wire between the audio isolation amplifier U2 and the audio power amplifier chip U1, directly solders the audio isolation amplifier U2 and the audio power amplifier chip U1 on the same circuit board, and connects the left and right channel contacts of the audio line input interface (port 2 and port 4 of terminal CN2) together. Although only mono audio can be played, the left or right channel audio can be played without limiting the audio of a certain channel. In this embodiment, terminal CN is provided with port 2, port 3 and port 4.

[0022] It is worth noting that the power module includes Schottky diodes D1, D2, D3, D4, D5, D6 and D7 connected in series; the positive electrode of Schottky diode D1 is used as the positive electrode of the input end of the power module, the negative electrode of the input end of the power module is grounded, and the cathode of Schottky diode D7 is used as the output end of the power module. The power supply of the audio power amplifier chip U1 can be reduced from 24V (connected from terminal CN1) to 19V close to the optimal power supply voltage, and connected to the power supply pin of the audio power amplifier chip U1 for power supply. This processing method can simply obtain the required voltage without going through the DC-DC conversion chip, and the method is simple and reliable.

[0023] Optionally, the power module further includes capacitors C2, C3, C4, C5, C6, C7, C8 and C9 connected in parallel; the first end of the capacitor C2 is electrically connected to the cathode of the Schottky diode D7, and the second end of the capacitor C2 is grounded. In this way, the purpose of filtering can be achieved.

[0024] Preferably, a capacitor C11 is provided at the second end of the primary side of the audio isolation amplifier U2, so that the second end of the primary side of the audio isolation amplifier U2 is electrically connected to the output end of the external player through the capacitor C11.

[0025] Specifically, the first end of the secondary side of the audio isolation amplifier U2 is provided with a capacitor C14, and the first end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input terminal INNR of the audio power amplifier chip U1 through the capacitor C14; the first end of the secondary side of the audio isolation amplifier U2 is provided with a capacitor C15, and the second end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input terminal INPR of the audio power amplifier chip U1 through the capacitor C15. The audio signal is input through the terminal CN2, and after charging the capacitor C10 or the capacitor C11 and inputting the signal to the audio isolation amplifier U2 (the capacitor C10 and the capacitor C11 are connected to the left and right channels of the player), an audio signal corresponding to the terminal CN2 is formed at the rear stage of the audio isolation amplifier U2, and an audio signal is formed by charging and discharging the capacitor C15 and inputted into the audio power amplifier chip U1, and then the audio is outputted through the speaker.

[0026] It is worth noting that it also includes an output processing module, which is arranged between the audio power amplifier chip U1 and the external speaker;

[0027] The output processing module includes an inductor L1, an inductor L2, a capacitor C18, a resistor R9, a capacitor C19, a capacitor C20 and a capacitor C21; the output end OUTNL of the audio power amplifier chip U1 is electrically connected to the first end of the inductor L1 and the first end of the capacitor C18, respectively, and the second end of the inductor L1 is electrically connected to the first end of the capacitor C19, the first end of the capacitor C20 and the second input end of the external speaker, respectively; the output end OUTNR of the audio power amplifier chip U1 is electrically connected to the first end of the inductor L2 and the first end of the resistor R9, respectively, and the second end of the inductor L2 is electrically connected to the second end of the capacitor C19, the first end of the capacitor C21 and the first input end of the external speaker, respectively; the second end of the capacitor C18 is electrically connected to the second end of the resistor R9, and the second end of the capacitor C20 is connected in parallel with the second end of the capacitor C21 and then grounded.

[0028] The two outputs of the speaker corresponding to the inductor L1 and the inductor L2 are used to stabilize the current and voltage. The capacitor C18 and the resistor R9 are a filter network that is used to filter out high-frequency noise. The capacitors C19, C20 and C21 also play the role of filtering out high-frequency noise.

[0029] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. An audio power amplifier with audio isolation, characterized in that: It includes a power module and an audio power amplifier chip U1 and an audio isolation amplifier U2 which are soldered on the same circuit board; The first end of the primary side of the audio isolation amplifier U2 is grounded, and the second end of the primary side of the audio isolation amplifier U2 is electrically connected to the output end of an external player; the first end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input end INNR of the audio power amplifier chip U1, the second end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input end INPR of the audio power amplifier chip U1, and the power input end PVCC of the audio power amplifier chip U1 is electrically connected to the output end of the power module; the output end OUTNR of the audio power amplifier chip U1 is electrically connected to the first input end of an external speaker, and the output end OUTNL of the audio power amplifier chip U1 is electrically connected to the second input end of the external speaker.

2. The audio power amplifier with audio isolation according to claim 1, characterized in that: The power module includes a Schottky diode D1, a Schottky diode D2, a Schottky diode D3, a Schottky diode D4, a Schottky diode D5, a Schottky diode D6 and a Schottky diode D7 which are connected in series in sequence; the anode of the Schottky diode D1 serves as the anode of the input end of the power module, the cathode of the input end of the power module is grounded, and the cathode of the Schottky diode D7 serves as the output end of the power module.

3. The audio power amplifier with audio isolation according to claim 2, characterized in that: The power module also includes capacitors C2, C3, C4, C5, C6, C7, C8 and C9 connected in parallel; a first end of the capacitor C2 is electrically connected to the cathode of the Schottky diode D7, and a second end of the capacitor C2 is grounded.

4. The audio power amplifier with audio isolation according to claim 1, characterized in that: A capacitor C11 is disposed at the second end of the primary side of the audio isolation amplifier U2, so that the second end of the primary side of the audio isolation amplifier U2 is electrically connected to the output end of an external player through the capacitor C11.

5. The audio power amplifier with audio isolation according to claim 1, characterized in that: A capacitor C14 is provided at the first end of the secondary side of the audio isolation amplifier U2, and the first end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input terminal INNR of the audio power amplifier chip U1 through the capacitor C14; a capacitor C15 is provided at the first end of the secondary side of the audio isolation amplifier U2, and the second end of the secondary side of the audio isolation amplifier U2 is electrically connected to the input terminal INPR of the audio power amplifier chip U1 through the capacitor C15.

6. The audio power amplifier with audio isolation according to claim 3, characterized in that: It also includes an output processing module, which is arranged between the audio power amplifier chip U1 and the external speaker; The output processing module includes an inductor L1, an inductor L2, a capacitor C18, a resistor R9, a capacitor C19, a capacitor C20 and a capacitor C21; the output end OUTNL of the audio power amplifier chip U1 is electrically connected to the first end of the inductor L1 and the first end of the capacitor C18, respectively, and the second end of the inductor L1 is electrically connected to the first end of the capacitor C19, the first end of the capacitor C20 and the second input end of the external speaker, respectively; the output end OUTNR of the audio power amplifier chip U1 is electrically connected to the first end of the inductor L2 and the first end of the resistor R9, respectively, and the second end of the inductor L2 is electrically connected to the second end of the capacitor C19, the first end of the capacitor C21 and the first input end of the external speaker, respectively; the second end of the capacitor C18 is electrically connected to the second end of the resistor R9, and the second end of the capacitor C20 is connected in parallel with the second end of the capacitor C21 and then grounded.

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