CN216794946U - Power amplifier circuit, playing device and audio system - Google Patents
Power amplifier circuit, playing device and audio system Download PDFInfo
- Publication number
- CN216794946U CN216794946U CN202123234302.XU CN202123234302U CN216794946U CN 216794946 U CN216794946 U CN 216794946U CN 202123234302 U CN202123234302 U CN 202123234302U CN 216794946 U CN216794946 U CN 216794946U
- Authority
- CN
- China
- Prior art keywords
- circuit
- power amplifier
- audio
- output
- amplifier circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000005236 sound signal Effects 0.000 claims abstract description 49
- 230000003321 amplification Effects 0.000 claims abstract description 26
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 26
- 239000003990 capacitor Substances 0.000 claims description 28
- 238000001914 filtration Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 9
- 230000008859 change Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
Images
Landscapes
- Amplifiers (AREA)
Abstract
The utility model discloses a power amplifier circuit, a playing device and an audio system, wherein the power amplifier circuit comprises: the audio input interface is used for accessing an audio signal; an audio output interface for outputting an audio signal; the double-differential power amplifier circuit is arranged between the audio input interface and the audio output interface in series and is used for carrying out differential amplification processing on an input audio signal and outputting the processed signal to the audio output interface; and the input end of the feedback control circuit is connected with the audio output interface, the output end of the feedback control circuit is connected with the second input end of the double-differential power amplifier circuit, and the feedback control circuit is used for converting the audio signal output by the audio output interface into a feedback signal and outputting the feedback signal to the double-differential power amplifier circuit so that the double-differential power amplifier circuit adjusts the output differential signal according to the feedback signal. The utility model can solve the problem of larger output direct current offset of the existing power amplifier.
Description
Technical Field
The utility model relates to the technical field of audio power amplification, in particular to a power amplifier circuit, playing equipment and an audio system.
Background
The output of the audio amplifier is ideally dc free and is ac output to drive the speaker to produce sound. In practice, due to circuit characteristics, component variations, and other factors, a large or small amount of output may remain dc. The output direct current of the power amplifier is more than one of important indexes for measuring the power amplifier. The dc bias high indicates that the circuit cannot completely reproduce the music signal, because the circuit itself has an offset, which means that there is distortion, and the amplified signal has distortion inevitably. The direct current voltage of power amplifier output finally will connect on the loudspeaker, and this direct current can lead to loudspeaker vibrating diaphragm to be in skew position, and it can lead to deviating more obvious to superpose audio signal again, therefore influences tone quality and reappears. The loudspeaker is an alternating current device, and when the output direct current of the power amplifier is large, the loudspeaker is damaged even due to the fact that the loudspeaker is in a heating state.
In order to make the output direct current of the power amplifier as low as possible, the positive voltage and the negative voltage of the power supply are required to be completely symmetrical, the components are required to be strictly paired, and the requirements on the circuit are required to be symmetrical as much as possible, which undoubtedly can cause cost increase and efficiency reduction. The existing power amplifier is usually added with a zero setting circuit, namely a circuit which can generate voltage or current opposite to the original deviation is added, and the zero setting circuit is adjusted by a manual method to offset the original deviation, so that the output state close to zero volt can be really achieved. However, a new offset is generated after the components are heated, which is equivalent to that the original setting is invalid, and the traditional zero setting circuit does not have the functions of automatic tracking and automatic correction unless manual adjustment is carried out again.
SUMMERY OF THE UTILITY MODEL
The utility model mainly aims to provide a power amplifier circuit, which aims to solve the problem that the output direct current offset of the conventional power amplifier is large.
In order to achieve the above object, the power amplifier circuit provided by the present invention comprises:
the audio input interface is used for accessing an audio signal;
an audio output interface for outputting an audio signal;
the double-differential power amplifier circuit is arranged between the audio input interface and the audio output interface in series and is used for carrying out differential amplification processing on an input audio signal and then outputting the audio signal to the audio output interface;
the input end of the feedback control circuit is connected with the audio output interface, the output end of the feedback control circuit is connected with the second input end of the double-differential power amplifier circuit, and the feedback control circuit is used for converting the audio signal output by the audio output interface into a feedback signal and outputting the feedback signal to the double-differential power amplifier circuit, so that the double-differential power amplifier circuit adjusts the output differential signal according to the feedback signal.
Optionally, the feedback control circuit comprises:
the input end of the integrating circuit is connected with the audio output interface, and the integrating circuit is used for integrating the audio signal output by the audio output interface and then outputting the audio signal;
and the input end of the inverting amplifying circuit is connected with the output end of the integrating circuit, the output end of the inverting amplifying circuit is connected with the second input end of the double-differential power amplifier circuit, and the inverting amplifying circuit is used for outputting the audio signal output by the integrating circuit after inverting amplification processing.
Optionally, the integrating circuit includes a first capacitor and a first operational amplifier, a negative input end of the first operational amplifier is connected to the audio output interface, a positive input end of the first operational amplifier is grounded, an output end of the first operational amplifier is connected to an input end of the inverting amplifier circuit, a first end of the first capacitor is connected to the negative input end of the first operational amplifier, and a second end of the first capacitor is connected to an output end of the first operational amplifier.
Optionally, the inverting amplifier circuit includes a first resistor, a second capacitor, and a second operational amplifier; the negative input end of the second operational amplifier is connected with the output end of the integrating circuit through the first resistor, the positive input end of the second operational amplifier is grounded, the output end of the second operational amplifier is connected with the second input end of the double-differential power amplifier circuit, the first end of the second resistor is connected with the negative input end of the second operational amplifier, the second end of the second resistor is connected with the output end of the second operational amplifier, and the second capacitor is connected with the second resistor in parallel.
Optionally, the first operational amplifier and the second operational amplifier are integrated in the same chip.
Optionally, the feedback control circuit further comprises:
the input end of the voltage-stabilizing power supply circuit is connected with a power supply, the output end of the voltage-stabilizing power supply circuit is respectively connected with the integrating circuit and the inverting amplifying circuit, and the voltage-stabilizing power supply circuit is used for converting the voltage output by the input power supply into power supply voltage so as to supply power for the integrating circuit and the inverting amplifying circuit.
Optionally, the feedback control circuit further comprises:
the input end of the filter circuit is connected with the audio output interface, the output end of the filter circuit is connected with the input end of the integrating circuit, and the filter circuit is used for filtering and outputting the audio signal output by the audio output interface.
Optionally, the power amplifier circuit further includes:
and the input end of the second amplifying circuit is connected with the output end of the double differential power amplifying circuit, the output end of the second amplifying circuit is connected with the audio output interface, and the second amplifying circuit is used for amplifying the differential signal output by the double differential power amplifying circuit and then outputting the amplified signal.
The utility model also provides a playing device, which comprises a loudspeaker and the power amplifier circuit;
and an audio output interface of the power amplifier circuit is connected with the loudspeaker.
The utility model also provides an audio system, which comprises the power amplifier circuit; or, include the aforementioned playback device.
According to the technical scheme, the double-differential power amplifier circuit is provided with the audio input interface, the audio output interface, the double-differential power amplifier circuit and the feedback control circuit, the double-differential power amplifier circuit is used for carrying out differential amplification processing on input audio signals and then outputting the audio signals to the audio output interface, and the feedback control circuit is used for converting the audio signals output by the audio output interface into feedback signals and outputting the feedback signals to the double-differential power amplifier circuit, so that the double-differential power amplifier circuit adjusts the output differential signals according to the feedback signals. The utility model realizes the function of automatically correcting the direct current offset by arranging the feedback control circuit and solves the problem of larger direct current offset output by the conventional power amplifier.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
Fig. 1 is a schematic diagram of functional modules of an embodiment of a power amplifier circuit according to the present invention;
fig. 2 is a schematic diagram of functional modules of an embodiment of a power amplifier circuit according to the present invention;
fig. 3 is a schematic circuit structure diagram of an embodiment of a double differential power amplifier circuit in the power amplifier circuit of the present invention;
fig. 4 is a schematic circuit structure diagram of an embodiment of a feedback control circuit in the power amplifier circuit according to the present invention;
fig. 5 is a schematic circuit structure diagram of a voltage-stabilizing power supply circuit in the power amplifier circuit according to an embodiment of the present invention.
The reference numbers illustrate:
| reference numerals | Name (R) | Reference numerals | Name (R) |
| 10 | Double-difference power amplification circuit | OUT1 | A |
| 20 | Feedback control circuit | OUT2 | |
| 30 | Second amplifying circuit | U1 | A first operational amplifier |
| 21 | Integrating circuit | U2 | Second operationAmplifier with a high- |
| 22 | Inverting amplifier circuit | DZ1 | First voltage regulator diode |
| 23 | Filter circuit | DZ2 | Second |
| 24 | Voltage-stabilizing power supply circuit | Q1～Q4 | First to fourth triodes |
| IN | Audio input interface | R1～R18 | First to eighteenth resistors |
| OUT | Audio output interface | C1～C8 | First to eighth capacitors |
| FB | Second input terminal |
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.
In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.
The utility model provides a power amplifier circuit, which is applied to a playing device, wherein the playing device comprises a loudspeaker.
At present, in order to make the power amplifier output direct current as low as possible, the positive voltage and the negative voltage of a power supply need to be completely symmetrical, components need to be strictly paired, and the requirements on the circuit are symmetrical as much as possible, which undoubtedly can cause cost increase and efficiency reduction. The existing power amplifier is usually added with a zero setting circuit, namely a circuit which can generate voltage or current opposite to the original deviation is added, and the zero setting circuit is adjusted by a manual method to offset the original deviation, so that the output state close to zero volt can be really achieved. However, a new offset is generated after the components are heated, which is equivalent to that the original setting is invalid, and the traditional zero setting circuit does not have the functions of automatic tracking and automatic correction unless manual adjustment is carried out again.
To solve the above problem, referring to fig. 1 to 5, in an embodiment, the power amplifier circuit includes:
an audio input interface IN for accessing an audio signal;
an audio output interface OUT for outputting an audio signal;
the double-differential power amplifier circuit 10 is arranged between the audio input interface IN and the audio output interface OUT IN series, and the double-differential power amplifier circuit 10 is used for carrying OUT differential amplification processing on an input audio signal and then outputting the processed signal;
the input end of the feedback control circuit 20 is connected to the audio output interface OUT, the output end of the feedback control circuit 20 is connected to the second input end FB of the double differential power amplifier circuit 10, and the feedback control circuit 20 is configured to convert the audio signal output by the audio output interface OUT into a feedback signal and output the feedback signal to the double differential power amplifier circuit 10, so that the double differential power amplifier circuit 10 adjusts the output differential signal according to the feedback signal.
In this embodiment, the double-differential power amplifier circuit 10 may be a double-differential amplifier circuit, which is a very classic preceding circuit in a power amplifier, and generally includes a power amplifier preceding circuit and a power amplifier subsequent circuit in an audio power amplifier, where the power amplifier preceding circuit converts an audio signal into a differential signal, and then sends the differential signal to the power amplifier subsequent circuit for amplification, and then outputs the differential signal to a speaker. As shown IN fig. 3, fig. 3 is a schematic circuit structure diagram of an embodiment of a double differential power amplifier circuit 10, wherein an audio input interface IN is connected to an audio signal input and connected to a first input terminal of the double differential power amplifier circuit 10, the audio signal is coupled through a fourth capacitor C4, a fifth resistor R5 is used for limiting a current, a filter circuit 23 composed of a sixth resistor R6 and a fifth capacitor C5 is output to a first triode Q1 and a second triode Q2 for differential amplification, and a first output terminal OUT1 and a second output terminal OUT2 output symmetric differential signals to a next stage of power amplifier circuit, that is, output differential signals with the same amplitude and opposite phases. The double-differential amplifying circuit is simple and good in overall performance in practical application, but symmetrical differential signals can be output only by manually selecting the amplification factors of the first triode Q1, the second triode Q2, the third triode Q3 and the fourth triode Q4 to ensure that the upper and lower tubes are symmetrical and consistent.
The amplifier tube in the double-differential power amplifier circuit 10 generates an error after working and heating, so that the voltages output by the first output end OUT1 and the second output end OUT2 are asymmetric, and the direct current offset is finally large through amplification of a power amplifier post-stage circuit. In this embodiment, the feedback control circuit 20 is connected to the second input terminal FB of the double differential power amplifier circuit 10, and the feedback control circuit 20 can generate a feedback signal by using the audio signal output by the audio output interface OUT, so that the double differential power amplifier circuit 10 can automatically correct the voltages output by the first output terminal OUT1 and the second output terminal OUT2 to approximately symmetrical levels, so that the dc offset is minimized, and the automatic servo function is realized. Specifically, the feedback control circuit 20 may be composed of an operational amplifier and a low pass filter, and the feedback control circuit 20 may utilize the operational amplifier to form the integrating circuit 21, and filter the audio signal output by the audio output interface OUT through the low pass filter to remove unnecessary signals, and finally generate the feedback signal. By utilizing the characteristics of the integrator circuit 21 in the feedback control circuit 20, the drift phenomenon of the double differential power amplifier circuit 10 caused by device mismatch or temperature change can be corrected, and finally, the voltage output by the first output end OUT1 and the second output end OUT2 of the double differential power amplifier circuit 10 is automatically corrected to a nearly symmetrical level, so that the direct current offset is minimized. The utility model enables the input of the power amplification circuit to follow the output by arranging the feedback control circuit 20, thereby forming a signal closed loop and realizing the function of automatic servo.
According to the utility model, the audio input interface IN, the audio output interface OUT, the double differential power amplifier circuit 10 and the feedback control circuit 20 are arranged, the double differential power amplifier circuit 10 is used for carrying OUT differential amplification processing on input audio signals and outputting symmetrical differential signals, the feedback control circuit 20 converts the audio signals output by the audio output interface OUT into feedback signals and outputs the feedback signals to the double differential power amplifier circuit 10, so that the double differential power amplifier circuit 10 adjusts the output differential signals according to the feedback signals, and the direct current offset of the output differential signals is minimized. According to the utility model, by arranging the feedback control circuit 20, the feedback control circuit 20 can generate a feedback signal by using an audio signal output by the audio output interface OUT, so that the drift phenomenon of the double differential power amplification circuit 10 caused by mismatching of devices or temperature change is corrected, and finally, the voltage output by the double differential power amplification circuit 10 is automatically corrected to a nearly symmetrical level, so that the direct current offset is minimized, the input and the output of the power amplification circuit are followed, a signal closed loop is formed, the automatic servo function is realized, the tone quality of the power amplification is improved, and the service life of the power amplification is prolonged. In addition, the utility model does not need to manually select the multiple of the differential tube to reduce the direct current offset, thereby avoiding the action that the differential tube needs to be additionally paired and improving the efficiency of mass production.
Referring to fig. 1 to 5, in an embodiment, the feedback control circuit 20 includes:
the input end of the integrating circuit 21 is connected to the audio output interface OUT, and the integrating circuit 21 is configured to integrate the audio signal output by the audio output interface OUT and output the integrated signal;
the input end of the inverting amplifier circuit 22 is connected to the output end of the integrating circuit 21, the output end of the inverting amplifier circuit 22 is connected to the second input end FB of the double differential power amplifier circuit 10, and the inverting amplifier circuit 22 is configured to perform inverting amplification processing on the audio signal output by the integrating circuit 21 and then output the audio signal.
In this embodiment, the integrating circuit 21 may be formed by an operational amplifier and a capacitor, and the inverting amplifying circuit 22 may be formed by an operational amplifier and discrete electronic devices such as a capacitor and a resistor. The integrating circuit 21 integrates the audio signal output from the audio output interface OUT and outputs the integrated signal, and the integrating circuit 21 has a function of integral compensation, but since the signal output from the integrating circuit 21 is inverted, the signal output from the integrating circuit 21 can be inverted and amplified by the inverting amplifier circuit 22, and a positive feedback signal can be obtained. The feedback control circuit 20 outputs the feedback signal to the negative phase of the double differential power amplifier circuit 10, that is, to the third transistor Q3 and the fourth transistor Q4, so as to adjust the amplification factors of the third transistor Q3 and the fourth transistor Q4, and realize automatic correction, so that the double differential power amplifier circuit 10 can correct the voltages output by the first output terminal OUT1 and the second output terminal OUT2 to approximately symmetrical levels. When the voltages output by the first output terminal OUT1 and the second output terminal OUT2 are approximately symmetrical, the dc offset of the second amplifying circuit 30 will be very small, so that the power amplifier output is close to a 0V state, and the tone quality of the power amplifier can be improved.
Further, the feedback control circuit 20 further includes:
the input end of the filter circuit 23 is connected to the audio output interface OUT, the output end of the filter circuit 23 is connected to the input end of the integrating circuit 21, and the filter circuit 23 is configured to filter the audio signal output by the audio output interface OUT and then output the filtered audio signal.
In this embodiment, the filter circuit 23 may be formed by discrete electronic devices such as a capacitor and a resistor, as shown in fig. 4, fig. 4 is a schematic circuit structure diagram of an embodiment of the feedback control circuit 20, wherein the third resistor R3, the fourth resistor R4, and the third capacitor C3 form the filter circuit 23. The audio signal output by the audio output interface OUT is filtered by the filter circuit 23 and then output to the integrating circuit 21, the integrating circuit 21 performs integration processing on the audio signal and then outputs to the inverting amplifier circuit 22, and the inverting amplifier circuit 22 performs inverting amplification processing, so that a positive-phase feedback signal can be obtained.
Referring to fig. 1 to 5, in an embodiment, the integrating circuit 21 includes a first capacitor C1 and a first operational amplifier U1, a negative input terminal of the first operational amplifier U1 is connected to the audio output interface OUT, a positive input terminal of the first operational amplifier U1 is connected to ground, an output terminal of the first operational amplifier U1 is connected to the input terminal of the inverting amplifier circuit 22, a first terminal of the first capacitor C1 is connected to the negative input terminal of the first operational amplifier U1, and a second terminal of the first capacitor C1 is connected to the output terminal of the first operational amplifier U1.
The inverting amplification circuit 22 comprises a first resistor R1, a second resistor R2, a second capacitor C2 and a second operational amplifier U2; the negative input end of the second operational amplifier U2 is connected to the output end of the integrating circuit 21 through the first resistor R1, the positive input end of the second operational amplifier U2 is grounded, the output end of the second operational amplifier U2 is connected to the second input end FB of the double differential power amplifier circuit 10, the first end of the second resistor R2 is connected to the negative input end of the second operational amplifier U2, the second end of the second resistor R2 is connected to the output end of the second operational amplifier U2, and the second capacitor C2 is connected to the second resistor R2 in parallel.
In this embodiment, as shown in fig. 4, fig. 4 is a schematic circuit diagram of an embodiment of the feedback control circuit 20, wherein a filter circuit 23 composed of a third resistor R3, a fourth resistor R4, and a third capacitor C3 performs filtering processing on an input audio signal, an integrating circuit 21 composed of a first capacitor C1 and a first operational amplifier U1 performs integration compensation, an inverting amplifier circuit 22 composed of a first resistor R1, a second resistor R2, a second capacitor C2, and a second operational amplifier U2 performs inverting amplification processing on a signal output by the integrating circuit 21, and then outputs a positive-phase feedback signal. The second capacitor C2 is connected in parallel across the second resistor R2, which can reduce signal interference.
Further, the first operational amplifier and the second operational amplifier are integrated within the same chip.
In this embodiment, the first operational amplifier U1 and the second operational amplifier U2 may be integrated on the same chip, and an operational amplifier chip with a model of TL072 may be selected, wherein pins 5, 6, and 7 of TL072 constitute the first operational amplifier U1, pins 1, 2, and 3 of TL072 constitute the second operational amplifier U2, pin 8 of TL072 is a power supply terminal, and pin 4 of TL072 is a ground terminal, i.e., the feedback control circuit 20 may select an operational amplifier chip with a model of TL072 and a peripheral circuit to implement feedback control.
Referring to fig. 1 to 5, in an embodiment, the feedback control circuit 20 further includes:
the input end of the voltage-stabilizing power supply circuit 24 is connected to a power supply, the output end of the voltage-stabilizing power supply circuit 24 is connected to the integrating circuit 21 and the inverting amplifier circuit 22, and the voltage-stabilizing power supply circuit 24 is configured to convert the voltage output by the input power supply into a power supply voltage to supply power to the integrating circuit 21 and the inverting amplifier circuit 22.
In this embodiment, as shown in fig. 5, fig. 4 is a schematic circuit diagram of an embodiment of the regulated power supply circuit 20, wherein the power supply supplies power to the integrating circuit 21 and the inverting amplifier circuit 22 through a seventeenth resistor R17, an eighteenth resistor R1, a seventh capacitor C7, an eighth capacitor C8, a first zener diode, and a second zener diode, that is, supplies power to the first operational amplifier U1 and the second operational amplifier U2. According to the utility model, by arranging the voltage-stabilizing power supply circuit 24, when the power output of the power supply changes, a 15V power supply voltage can still be provided for the first operational amplifier U1 and the second operational amplifier U2, so that the stability of the feedback control circuit 20 is improved.
Referring to fig. 1 to 5, in an embodiment, the power amplifier circuit further includes:
the input end of the second amplifying circuit 30 is connected with the output end of the double differential power amplifier circuit 10, the output end of the second amplifying circuit 30 is connected with the audio output interface OUT, and the second amplifying circuit 30 is used for amplifying the differential signal output by the double differential power amplifier circuit 10 and then outputting the amplified signal.
In this embodiment, the power amplifier circuit includes a double differential power amplifier circuit 10 and a second amplifier circuit 30, which are equivalent to a power amplifier pre-stage circuit and a power amplifier post-stage circuit in an audio power amplifier. The second amplifying circuit 30 is used for further amplifying the signal output by the double differential power amplifying circuit 10 to push the speaker to output sound. The second amplifying circuit 30 may be formed by a basic amplifying circuit, and may further be provided with a power amplifying circuit to increase the signal power, so as to better drive the speaker to emit sound. The second amplifying circuit 30 is mainly used for further amplifying the signal output by the double differential power amplifying circuit 10, so that when the voltage output by the double differential power amplifying circuit 10 is asymmetric, the second amplifying circuit 30 further amplifies the signal output by the double differential power amplifying circuit 10, which may result in a large dc offset of the finally output signal. Therefore, in this embodiment, the feedback control circuit 20 is arranged to convert the audio signal output by the audio output interface OUT, i.e. the audio signal output by the second amplifying circuit 30, into a feedback signal, so that the double-differential power amplifier circuit 10 adjusts the output voltage to a nearly symmetrical level according to the feedback signal, and the signal dc offset after the amplification by the second amplifying circuit 30 is small, so that the power amplifier outputs a state close to 0V, thereby improving the sound quality of the power amplifier.
The present invention further provides a playing device, which includes a speaker and the above power amplifier circuit, and the specific structure of the power amplifier circuit refers to the above embodiments, and since the playing device adopts all the technical solutions of all the above embodiments, the playing device at least has all the beneficial effects brought by the technical solutions of the above embodiments, and is not described herein any more; wherein,
and an audio output interface OUT of the power amplifier circuit is connected with the loudspeaker.
The present invention further provides an audio system, where the electronic device includes the power amplifier circuit or includes the playback device, and the specific structure of the audio system refers to the foregoing embodiments.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. A power amplifier circuit, comprising:
the audio input interface is used for accessing an audio signal;
an audio output interface for outputting an audio signal;
the double-differential power amplifier circuit is arranged between the audio input interface and the audio output interface in series and is used for carrying out differential amplification processing on an input audio signal and then outputting the audio signal to the audio output interface;
the input end of the feedback control circuit is connected with the audio output interface, the output end of the feedback control circuit is connected with the second input end of the double-differential power amplifier circuit, and the feedback control circuit is used for converting the audio signal output by the audio output interface into a feedback signal and outputting the feedback signal to the double-differential power amplifier circuit, so that the double-differential power amplifier circuit adjusts the output differential signal according to the feedback signal.
2. The power amplifier circuit of claim 1, wherein the feedback control circuit comprises:
the input end of the integrating circuit is connected with the audio output interface, and the integrating circuit is used for integrating the audio signal output by the audio output interface and then outputting the audio signal;
and the input end of the inverting amplifying circuit is connected with the output end of the integrating circuit, the output end of the inverting amplifying circuit is connected with the second input end of the double-differential power amplifier circuit, and the inverting amplifying circuit is used for outputting the audio signal output by the integrating circuit after inverting amplification processing.
3. The power amplifier circuit according to claim 2, wherein the integrator circuit comprises a first capacitor and a first operational amplifier, a negative input terminal of the first operational amplifier is connected to the audio output interface, a positive input terminal of the first operational amplifier is grounded, an output terminal of the first operational amplifier is connected to the input terminal of the inverting amplifier circuit, a first terminal of the first capacitor is connected to the negative input terminal of the first operational amplifier, and a second terminal of the first capacitor is connected to the output terminal of the first operational amplifier.
4. The power amplifier circuit of claim 3, wherein the inverting amplifier circuit comprises a first resistor, a second capacitor, and a second operational amplifier; the negative input end of the second operational amplifier is connected with the output end of the integrating circuit through the first resistor, the positive input end of the second operational amplifier is grounded, the output end of the second operational amplifier is connected with the second input end of the double-differential power amplifier circuit, the first end of the second resistor is connected with the negative input end of the second operational amplifier, the second end of the second resistor is connected with the output end of the second operational amplifier, and the second capacitor is connected with the second resistor in parallel.
5. The power amplifier circuit of claim 4, wherein the first operational amplifier and the second operational amplifier are integrated within a same chip.
6. The power amplifier circuit of claim 2, wherein the feedback control circuit further comprises:
the input end of the voltage-stabilizing power supply circuit is connected with a power supply, the output end of the voltage-stabilizing power supply circuit is respectively connected with the integrating circuit and the inverting amplifying circuit, and the voltage-stabilizing power supply circuit is used for converting the voltage output by the power supply into power supply voltage so as to supply power for the integrating circuit and the inverting amplifying circuit.
7. The power amplifier circuit of claim 2, wherein the feedback control circuit further comprises:
the input end of the filter circuit is connected with the audio output interface, the output end of the filter circuit is connected with the input end of the integrating circuit, and the filter circuit is used for filtering and outputting the audio signal output by the audio output interface.
8. The power amplifier circuit of claim 1, wherein the power amplifier circuit further comprises:
and the input end of the second amplifying circuit is connected with the output end of the double differential power amplifying circuit, the output end of the second amplifying circuit is connected with the audio output interface, and the second amplifying circuit is used for amplifying the differential signal output by the double differential power amplifying circuit and then outputting the amplified signal.
9. A playback device, comprising a speaker and the power amplifier circuit according to any one of claims 1 to 8;
and an audio output interface of the power amplifier circuit is connected with the loudspeaker.
10. An audio system comprising a power amplifier circuit according to any one of claims 1 to 8; or comprising a playback device as claimed in claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123234302.XU CN216794946U (en) | 2021-12-20 | 2021-12-20 | Power amplifier circuit, playing device and audio system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123234302.XU CN216794946U (en) | 2021-12-20 | 2021-12-20 | Power amplifier circuit, playing device and audio system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216794946U true CN216794946U (en) | 2022-06-21 |
Family
ID=82009893
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202123234302.XU Active CN216794946U (en) | 2021-12-20 | 2021-12-20 | Power amplifier circuit, playing device and audio system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216794946U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115567007A (en) * | 2022-12-05 | 2023-01-03 | 四川湖山电器股份有限公司 | Power amplifier direct current operating point tracking circuit |
-
2021
- 2021-12-20 CN CN202123234302.XU patent/CN216794946U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115567007A (en) * | 2022-12-05 | 2023-01-03 | 四川湖山电器股份有限公司 | Power amplifier direct current operating point tracking circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7843263B2 (en) | Power amplifier with noise shaping function | |
| CN109347513B (en) | bidding procurement information calibration circuit | |
| US7545212B2 (en) | Class ad audio amplifier | |
| CN216794946U (en) | Power amplifier circuit, playing device and audio system | |
| CN105720927A (en) | Frequency-compensated transconductance amplifier | |
| TWI647905B (en) | Pre-compensator for compensating the linearity of the amplifier | |
| CN108776500A (en) | It is a kind of based on frequency compensation and transient response improve circuit without capacitance LDO outside piece | |
| US20050001687A1 (en) | Power amplifier module with distortion compensation | |
| US7696822B2 (en) | Amplifying circuit and associated linearity improving method | |
| US6057737A (en) | Non-linear asymmetrical audio amplifiers | |
| JPH057883B2 (en) | ||
| US9590570B2 (en) | Impedance converter circuit for condenser microphone | |
| CN109150188B (en) | A kind of current mode digital-to-analog converter output-stage circuit of adjustable output common mode level | |
| CN100582991C (en) | Voltage stabilizer circuit | |
| WO2019161655A1 (en) | Feedback control circuit for power amplifier | |
| CN104320105A (en) | A mixed model capacitance multiplier circuit | |
| US7701283B2 (en) | Power amplifier with noise shaping | |
| US20080042744A1 (en) | Output circuit of vacuum-tube amplifier | |
| CN215010182U (en) | Gain adjusting circuit | |
| CN112671233B (en) | Compensation circuit and switching power supply | |
| TWI833350B (en) | Linear amplifier and supply modulator | |
| US5136254A (en) | FM demodulator circuit whose demodulation output is decreased in distortion | |
| CN218481788U (en) | Quick-response voltage stabilizing circuit | |
| US20170054417A1 (en) | System and method for improving total harmonic distortion of an amplifier | |
| TW201843927A (en) | Predistorter for compensating linearity of amplifier |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |