CN109104673B - Digital audio power amplifier system - Google Patents

Digital audio power amplifier system Download PDF

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Publication number
CN109104673B
CN109104673B CN201810979078.0A CN201810979078A CN109104673B CN 109104673 B CN109104673 B CN 109104673B CN 201810979078 A CN201810979078 A CN 201810979078A CN 109104673 B CN109104673 B CN 109104673B
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switch
resistor
input end
output end
power amplifier
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CN109104673A (en
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周佳宁
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Shanghai Awinic Technology Co Ltd
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Shanghai Awinic Technology Co Ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/12—Circuits for transducers, loudspeakers or microphones for distributing signals to two or more loudspeakers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2430/00—Signal processing covered by H04R, not provided for in its groups
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

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  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)

Abstract

The invention provides a digital audio power amplifier system, which comprises: the system comprises a first subsystem, a second subsystem, a feedback module and an adjusting module; according to the digital audio power amplifier system, the feedback module and the adjusting module are arranged, and control signals are combined, so that the adjusting module is in different working states, the resistance matching degree of the first subsystem and the second subsystem is adjusted, and the power supply rejection ratio of the digital audio power amplifier system is adjusted, so that noise on a loudspeaker is eliminated.

Description

Digital audio power amplifier system
Technical Field
The invention relates to the technical field of semiconductor integrated circuits, in particular to a digital audio power amplifier system.
Background
The front class-D audio power amplifier has wide application due to the efficiency exceeding 80%, and particularly, the high efficiency is important for mobile equipment, so that the working time can be prolonged, and the heating value of handheld equipment such as mobile phones can be reduced.
In application fields such as mobile phones, volume and tone quality can have important influence on user experience, and the current trend is that an audio power amplifier outputs higher power to obtain larger volume and better tone quality.
However, in order to output higher emission power, the current digital audio power amplifier system needs to draw a large amount of current from the power supply, and because the power supply has a certain internal resistance, a large range of fluctuation can continuously appear on the power supply, namely the power supply rejection ratio cannot be controlled, and larger noise can be heard on the loudspeaker.
Disclosure of Invention
In order to solve the above problems, the present invention provides a digital audio power amplifier system, which can adjust the power supply rejection ratio to eliminate the noise on the loudspeaker.
In order to achieve the above purpose, the present invention provides the following technical solutions:
a digital audio power amplifier system comprising: the system comprises a first subsystem, a second subsystem, a feedback module and an adjusting module;
the first subsystem includes: the output end of the first current source module is connected with the first input end of the first power amplification loop, the input end of the first current source module is used as the signal input end of the first subsystem and used for receiving PWMP signals, and the output end of the first power amplification loop is used as the output end of the first subsystem;
the second subsystem includes: the output end of the second current source module is connected with the first input end of the second power amplification loop, the input end of the second current source module is used as the signal input end of the second subsystem and used for receiving PWMN signals, and the output end of the second power amplification loop is used as the output end of the second subsystem;
the first input end of the feedback module is connected with the first input end of the first power amplification loop, the second input end of the feedback module is connected with the first input end of the second power amplification loop, the first output end of the feedback module is connected with the first input end of the adjusting module, and the second output end of the feedback module is connected with the second input end of the adjusting module;
the first output end of the adjusting module is connected with the output end of the first power amplifier loop, and the second output end of the adjusting module is connected with the output end of the second power amplifier loop;
the control end of the adjusting module is used for receiving control signals, and the control signals are used for controlling the adjusting module to be in different working states so as to adjust the resistance matching degree of the first subsystem and the second subsystem and further adjust the power supply rejection ratio of the digital audio power amplifier system;
the periods of the control signal, the PWMP signal, and the PWMN signal are the same.
Preferably, the feedback module includes: a first feedback resistor and a second feedback resistor;
the first end of the first feedback resistor is connected with the first input end of the first power amplifier loop, and the second end of the first feedback resistor is connected with the first input end of the regulating module;
and the first end of the second feedback resistor is connected with the first input end of the second power amplifier loop, and the second end of the second feedback resistor is connected with the second input end of the regulating module.
Preferably, the adjusting module includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, and an eighth switch;
the input end of the first switch and the input end of the second switch are connected with the first output end of the feedback module;
the output end of the third switch and the output end of the fourth switch are connected with the output end of the first power amplifier loop;
the input end of the fifth switch and the input end of the sixth switch are connected with the second output end of the feedback module;
the output end of the seventh switch and the output end of the eighth switch are connected with the output end of the second power amplifier loop;
the output end of the first switch and the output end of the fifth switch are connected with the first end of the first resistor, and the second end of the first resistor is connected with the input end of the third switch and the input end of the seventh switch respectively;
the first end of the second resistor is connected with the first end of the first resistor, and the second end of the second resistor is grounded;
the output end of the second switch and the output end of the sixth switch are connected with the first end of the third resistor, and the second end of the third resistor is connected with the input end of the fourth switch and the input end of the eighth switch respectively;
the first end of the fourth resistor is connected with the first end of the third resistor, and the second end of the fourth resistor is grounded;
the control ends of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch and the eighth switch are used for receiving the control signals, and the control signals are used for controlling the working states of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch and the eighth switch;
when the first switch, the third switch, the sixth switch and the eighth switch are in a conducting state, the other switches are in a closing state;
when the second switch, the fourth switch, the fifth switch and the seventh switch are in an on state, the rest switches are in an off state.
Preferably, the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch and the eighth switch are field effect transistors.
Preferably, the first switch, the third switch, the sixth switch and the eighth switch are P-type field effect transistors;
the second switch, the fourth switch, the fifth switch and the seventh switch are N-type field effect transistors.
Preferably, the first switch, the third switch, the sixth switch and the eighth switch are all N-type field effect transistors;
the second switch, the fourth switch, the fifth switch and the seventh switch are P-type field effect transistors.
Preferably, the digital audio power amplifier system further comprises: a common mode voltage generating module;
and the second input end of the first power amplifier loop and the second input end of the second power amplifier loop are connected with the output end of the common-mode voltage generating module.
Preferably, the common mode voltage generating module includes: a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a capacitor;
the first end of the fifth resistor is connected with the voltage input end, the second end of the fifth resistor is connected with the first end of the sixth resistor, the second end of the sixth resistor is connected with the first end of the seventh resistor, and the second end of the seventh resistor is grounded;
the first end of the eighth resistor is connected with the first end of the seventh resistor, the second end of the eighth resistor is connected with the first end of the capacitor, and the second end of the capacitor is connected with the second end of the seventh resistor;
and a connecting node of the eighth resistor and the capacitor is used as an output end of the common-mode voltage generating module.
As can be seen from the above description, the digital audio power amplifier system provided by the invention combines the feedback module and the adjustment module with the control signal to make the adjustment module in different working states so as to adjust the resistance matching degree of the first subsystem and the second subsystem, and further adjust the power supply rejection ratio of the digital audio power amplifier system so as to eliminate noise on the loudspeaker.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a digital power amplifier system according to an embodiment of the present invention;
fig. 2 is another schematic structural diagram of the digital power amplifier system according to the embodiment of the present invention;
fig. 3 is a schematic diagram of a common-mode voltage generating module according to an embodiment of the invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a digital power amplifier system according to an embodiment of the present invention, which is used for converting a PWM signal processed by a digital module into an analog signal, where the digital power amplifier system includes: a first subsystem, a second subsystem, a feedback module 15 and an adjustment module 16;
the first subsystem includes: the output end of the first current source module 11 is connected with the first input end of the first power amplification loop 12, the input end of the first current source module 11 is used as the signal input end of the first subsystem and is used for receiving PWMP signals, and the output end of the first power amplification loop 12 is used as the output end VOUTP of the first subsystem;
the second subsystem includes: the output end of the second current source module 13 is connected with the first input end of the second power amplification loop 14, the input end of the second current source module 13 is used as the signal input end of the second subsystem and is used for receiving PWMN signals, and the output end of the second power amplification loop 14 is used as the output end VOUTN of the second subsystem;
a first input end of the feedback module 15 is connected with a first input end of the first power amplification loop 12, a second input end of the feedback module 15 is connected with a first input end of the second power amplification loop 14, a first output end of the feedback module 15 is connected with a first input end of the adjusting module 16, and a second output end of the feedback module 15 is connected with a second input end of the adjusting module 16;
a first output end of the adjusting module 16 is connected with an output end of the first power amplifier loop 12, and a second output end of the adjusting module 16 is connected with an output end of the second power amplifier loop 14;
the control end of the adjusting module 16 is configured to receive a control signal SWAP, where the control signal SWAP is configured to control the adjusting module 16 to be in different working states, so as to adjust the resistance matching degree of the first subsystem and the second subsystem, and further adjust the power supply rejection ratio of the digital audio power amplifier system;
the control signal SWAP, the PWMP signal, and the PWMN signal have the same period.
As can be seen from the above description, the digital audio power amplifier system provided by the invention combines the feedback module and the adjustment module with the control signal to make the adjustment module in different working states so as to adjust the resistance matching degree of the first subsystem and the second subsystem, and further adjust the power supply rejection ratio of the digital audio power amplifier system so as to eliminate noise on the loudspeaker.
Further, as shown in fig. 1, the digital audio power amplifier system further includes: a common mode voltage generating module 17;
the second input end of the first power amplifier loop 12 and the second input end of the second power amplifier loop 14 are both connected with the output end VREF of the common mode voltage generating module 17.
The common-mode voltage generating module 17 is configured to generate a common-mode voltage signal for maintaining stability of output signals of the first current source module 11 and the second current source module 13.
Further, as shown in fig. 2, the first current source module 11 includes a first current source IDAC1, a second current source IDAC2, a switch a and a switch B.
The input end of the first current source IDAC1 is connected with the power supply voltage end VDD, the output end of the first current source IDAC1 is connected with the input end of the switch a, the output end of the switch a is connected with the input end of the switch B, the output end of the switch B is grounded through the second current source IDAC2, and the control ends of the switch a and the switch B serve as the input end of the first current source module 11 and are used for receiving PWMP signals.
Further, as shown in fig. 2, the first power amplifier loop 12 includes a first operational amplifier 21, a power amplifier loop driving module 23, a first capacitor C1, a first fet P1, and a second fet N1;
the inverting input end of the first operational amplifier 21 is connected with the output end of the first current source module 11, the non-inverting input end of the first operational amplifier 21 is connected with the output end of the common-mode voltage generating module 17, the output end of the first operational amplifier 21 is connected with the input end of the power amplifier loop driving module 23, the first output end of the power amplifier loop driving module 23 is connected with the grid electrode of the first field effect transistor P1, and the second output end of the power amplifier loop driving module 23 is connected with the grid electrode of the second field effect transistor N1.
The source electrode of the first field effect tube P1 is connected with the voltage input end PVDD, the drain electrode of the first field effect tube P1 is connected with the drain electrode of the second field effect tube N1, the source electrode of the second field effect tube N1 is grounded, and the connection node of the first field effect tube P1 and the second field effect tube N1 is used as the output end VOUTP of the first power amplification loop.
The first capacitor C1 has a first end connected to the output terminal of the first operational amplifier 21, and a second end connected to the inverting input terminal of the first operational amplifier 21.
Further, as shown in fig. 2, the second current source module 13 includes a third current source IDAC3, a fourth current source IDAC4, a switch C and a switch D.
The input end of the third current source IDAC3 is connected with the power supply voltage end VDD, the output end of the third current source IDAC3 is connected with the input end of the switch C, the output end of the switch C is connected with the input end of the switch D, the output end of the switch D is grounded through the fourth current source IDAC4, and the control ends of the switch C and the switch D serve as the input end of the second current source module 13 and are used for receiving PWMN signals.
Further, as shown in fig. 2, the second power amplifier loop 14 includes a second operational amplifier 22, a power amplifier loop driving module 24, a second capacitor C2, a third fet P2, and a fourth fet N2;
the inverting input end of the second operational amplifier 22 is connected with the output end of the second current source module 13, the non-inverting input end of the second operational amplifier 22 is connected with the output end of the common-mode voltage generating module 17, the output end of the second operational amplifier 22 is connected with the input end of the power amplifier loop driving module 24, the first output end of the power amplifier loop driving module 24 is connected with the gate of the third field effect transistor P2, and the second output end of the power amplifier loop driving module 24 is connected with the gate of the fourth field effect transistor N2.
The source electrode of the third field effect transistor P2 is connected with the voltage input end PVDD, the drain electrode of the third field effect transistor P2 is connected with the drain electrode of the fourth field effect transistor N2, the source electrode of the fourth field effect transistor N2 is grounded, and the connection node of the third field effect transistor P2 and the fourth field effect transistor N2 is used as the output end of the second power amplifier loop.
The first end of the second capacitor C2 is connected to the output end of the second operational amplifier 22, and the second end is connected to the inverting input end of the second operational amplifier 22.
Further, as shown in fig. 2, the feedback module includes: a first feedback resistor RFB1 and a second feedback resistor RFB2;
a first end of the first feedback resistor RFB1 is connected to the first input end of the first power amplifier loop 12, and a second end is connected to the first input end of the adjusting module 16;
the first end of the second feedback resistor RFB2 is connected to the first input end of the second power amplifier loop 14, and the second end is connected to the second input end of the adjusting module 16.
Further, as shown in fig. 2, the adjusting module 16 includes: the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7 and the eighth switch S8;
the input end of the first switch S1 and the input end of the second switch S2 are both connected with the first output end of the feedback module 15;
the output end of the third switch S3 and the output end of the fourth switch S4 are connected with the output end of the first power amplifier loop 12;
the input end of the fifth switch S5 and the input end of the sixth switch S6 are both connected with the second output end of the feedback module 15;
the output end of the seventh switch S7 and the output end of the eighth switch S8 are connected with the output end of the second power amplification loop 14;
the output end of the first switch S1 and the output end of the fifth switch S5 are both connected with the first end of the first resistor R1, and the second end of the first resistor R1 is connected with the input end of the third switch S3 and the input end of the seventh switch S7 respectively;
the first end of the second resistor R2 is connected with the first end of the first resistor R1, and the second end of the second resistor R2 is grounded;
the output end of the second switch S2 and the output end of the sixth switch S6 are both connected with the first end of the third resistor R3, and the second end of the third resistor R3 is connected with the input end of the fourth switch S4 and the input end of the eighth switch S8 respectively;
the first end of the fourth resistor R4 is connected with the first end of the third resistor R3, and the second end of the fourth resistor R4 is grounded;
the control ends of the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7 and the eighth switch S8 are used for receiving the control signals, and the control signals are used for controlling the working states of the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7 and the eighth switch S8;
when the first switch S1, the third switch S3, the sixth switch S6 and the eighth switch S8 are in a conducting state, the other switches are in a closing state;
when the second switch S2, the fourth switch S4, the fifth switch S5, and the seventh switch S7 are in an on state, the remaining switches are in an off state.
It should be noted that, by setting the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4, the digital audio power amplifier system generates a higher output voltage.
Optionally, the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7 and the eighth switch S8 are field effect transistors.
Optionally, the first switch S1, the third switch S3, the sixth switch S6, and the eighth switch S8 are P-type field effect transistors;
the second switch S2, the fourth switch S4, the fifth switch S5, and the seventh switch S7 are N-type field effect transistors.
Optionally, the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7 and the eighth switch S8 are N-type field effect transistors;
the second switch S2, the fourth switch S4, the fifth switch S5, and the seventh switch S7 are P-type field effect transistors.
Further, as shown in fig. 3, the common-mode voltage generating module 17 includes: a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a capacitor C;
the first end of the fifth resistor R5 is connected with the voltage input end PVDD, the second end of the fifth resistor R5 is connected with the first end of the sixth resistor R6, the second end of the sixth resistor R6 is connected with the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is grounded;
the first end of the eighth resistor R8 is connected with the first end of the seventh resistor R7, the second end of the eighth resistor R8 is connected with the first end of the capacitor C, and the second end of the capacitor C is connected with the second end of the seventh resistor R7;
the connection node of the eighth resistor R8 and the capacitor C serves as the output terminal VREF of the common-mode voltage generating module 17.
The resistance values of the fifth resistor R5, the sixth resistor R6 and the seventh resistor R7 are the same.
Based on the digital audio power amplifier system provided above, when the adjusting module 16 is not provided with the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7 and the eighth switch S8, the adjusting module 16 is divided into two parts, one part is composed of the first resistor R1 and the second resistor R2, the first feedback resistor RFB1 is correspondingly connected with the first subsystem, the other part is composed of the third resistor R3 and the fourth resistor R4, and the second feedback resistor RFB2 is correspondingly connected with the second subsystem.
At this time, assuming that the equivalent output impedance of the first current source module 11 and the second current source module 13 is r0,
the signal ripple Δvip at the output Vip of the first current source module 11 is,
wherein DeltaV OUTP Is the output terminal V of the first subsystem OUTP Is a fluctuation in the output of (a).
Since the gain of the first power amplifier loop 12 is very large at the low frequency band, the gain from the input VREF of the first operational amplifier 21 to Vip is equal to 1, and thus,
where Δpvdd is the voltage ripple at the voltage input.
The finishing is carried out so as to obtain the finished products,
in the same way, it is known that,
wherein DeltaV OUTN Is the output terminal V of the second subsystem OUTN Is a fluctuation in the output of (a).
It is assumed that the number of the sub-blocks,
in the actual manufacturing process, the resistance of the resistor will have a certain fluctuation, and the first resistor R 1 A second resistor R 2 Third resistor R 3 And a fourth voltage R 4 Deviations may occur in the partial pressure ratio and the design value of (c).
It is again assumed that,
α1-α2＝Δα
the equivalent output impedance R0 of the first current source module 11 and the second current source module 13 is much larger than the first feedback resistance R FB1 And a second feedback resistor R FB2 It can therefore be derived that the number of the cells,
ΔV OUT ＝ΔV OUTP -ΔV OUTN
wherein DeltaV OUT Is the total output fluctuation of the digital audio power amplifier system.
That is to say,
then, the power supply rejection ratio PSRR of the digital audio power amplifier system is,
from the above formula, the main factor affecting the power supply rejection ratio PSRR of the high-voltage digital audio power amplifier system is the first resistor R 1 A second resistor R 2 Third resistor R 3 And a fourth voltage R 4 Is a degree of matching of (a).
Thus, in this embodiment, by setting the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7 and the eighth switch S8, the first switch S1, the third switch S3, the sixth switch S6 and the eighth switch S8 are turned on when the switch signal is high, and the other switches are turned off when the switch signal is low, and the output terminal V of the first subsystem is turned on OUTP Through a first feedback resistor R FB1 A first resistor R 1 And a second resistor R 2 Current is fed or drawn into the output Vip of the first current source module, at which time the output V of the second subsystem OUTN Through a second feedback resistor R FB2 Third resistor R 3 And a fourth resistor R 4 Current is sunk or drawn into the output terminal Vin of the second current source module. When the SWAP signal is at low level, the second switch S2, the fourth switch S4, the fifth switch S5 and the seventh switch S7 are in on state, the other switches are in off state, and the output terminal V of the first subsystem OUTP Through a first feedback resistor R FB1 Third resistor R 3 And a fourth resistor R 4 Current is fed or drawn into the output Vip of the first current source module, at which time the output V of the second subsystem OUTN Through a second feedback resistor R FB2 A first resistor R 1 And a second resistor R 2 Current is sunk or drawn into the output terminal Vin of the second current source module.
The PWMP signal period and the PWMN signal period are the same as the SWAP signal period.
Thus, it can be derived that,
at this time, the output terminal V of the first subsystem OUTP And the feedback ratio of the second subsystem and the output V OUTN Is the same in feedback ratio, power supply is suppressedThe voltage division resistance mismatch factor delta alpha caused by the manufacturing process in the system ratio PSRR can be perfectly eliminated, so that the power supply rejection ratio PSRR of the digital audio power amplifier system is improved.
The above describes a digital audio power amplifier system provided by the present invention in detail, and specific examples are applied to illustrate the principles and embodiments of the present invention, and the above examples are only used to help understand the method and core ideas of the present invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.
It should be noted that, in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described as different from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.
It is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include, or is intended to include, elements inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. A digital audio power amplifier system, comprising: the system comprises a first subsystem, a second subsystem, a feedback module and an adjusting module;
the first subsystem includes: the output end of the first current source module is connected with the first input end of the first power amplification loop, the input end of the first current source module is used as the signal input end of the first subsystem and used for receiving PWMP signals, and the output end of the first power amplification loop is used as the output end of the first subsystem;
the second subsystem includes: the output end of the second current source module is connected with the first input end of the second power amplification loop, the input end of the second current source module is used as the signal input end of the second subsystem and used for receiving PWMN signals, and the output end of the second power amplification loop is used as the output end of the second subsystem;
the first input end of the feedback module is connected with the first input end of the first power amplification loop, the second input end of the feedback module is connected with the first input end of the second power amplification loop, the first output end of the feedback module is connected with the first input end of the adjusting module, and the second output end of the feedback module is connected with the second input end of the adjusting module;
the first output end of the adjusting module is connected with the output end of the first power amplifier loop, and the second output end of the adjusting module is connected with the output end of the second power amplifier loop;
the control end of the adjusting module is used for receiving control signals, and the control signals are used for controlling the adjusting module to be in different working states so as to adjust the resistance matching degree of the first subsystem and the second subsystem and further adjust the power supply rejection ratio of the digital audio power amplifier system;
the periods of the control signal, the PWMP signal and the PWMN signal are the same;
wherein, the adjustment module includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, and an eighth switch;
the input end of the first switch and the input end of the second switch are connected with the first output end of the feedback module;
the output end of the third switch and the output end of the fourth switch are connected with the output end of the first power amplifier loop;
the input end of the fifth switch and the input end of the sixth switch are connected with the second output end of the feedback module;
the output end of the seventh switch and the output end of the eighth switch are connected with the output end of the second power amplifier loop;
the output end of the first switch and the output end of the fifth switch are connected with the first end of the first resistor, and the second end of the first resistor is connected with the input end of the third switch and the input end of the seventh switch respectively;
the first end of the second resistor is connected with the first end of the first resistor, and the second end of the second resistor is grounded;
the output end of the second switch and the output end of the sixth switch are connected with the first end of the third resistor, and the second end of the third resistor is connected with the input end of the fourth switch and the input end of the eighth switch respectively;
the first end of the fourth resistor is connected with the first end of the third resistor, and the second end of the fourth resistor is grounded;
the control ends of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch and the eighth switch are used for receiving the control signals, and the control signals are used for controlling the working states of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch and the eighth switch.
2. The digital audio power amplifier system of claim 1, wherein the feedback module comprises: a first feedback resistor and a second feedback resistor;
the first end of the first feedback resistor is connected with the first input end of the first power amplifier loop, and the second end of the first feedback resistor is connected with the first input end of the regulating module;
and the first end of the second feedback resistor is connected with the first input end of the second power amplifier loop, and the second end of the second feedback resistor is connected with the second input end of the regulating module.
3. The digital audio power amplifier system of claim 1, wherein when the first switch, the third switch, the sixth switch, and the eighth switch are in an on state, the remaining switches are in an off state;
when the second switch, the fourth switch, the fifth switch and the seventh switch are in an on state, the rest switches are in an off state.
4. The digital audio power amplifier system of claim 1, wherein the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch, the seventh switch, and the eighth switch are field effect transistors.
5. The digital audio power amplifier system of claim 1, wherein the first switch, the third switch, the sixth switch, and the eighth switch are P-type field effect transistors;
the second switch, the fourth switch, the fifth switch and the seventh switch are N-type field effect transistors.
6. The digital audio power amplifier system of claim 1, wherein the first switch, the third switch, the sixth switch, and the eighth switch are N-type field effect transistors;
the second switch, the fourth switch, the fifth switch and the seventh switch are P-type field effect transistors.
7. The digital audio power amplifier system of claim 1, further comprising: a common mode voltage generating module;
and the second input end of the first power amplifier loop and the second input end of the second power amplifier loop are connected with the output end of the common-mode voltage generating module.
8. The digital audio power amplifier system of claim 7, wherein the common mode voltage generation module comprises: a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a capacitor;
the first end of the fifth resistor is connected with the voltage input end, the second end of the fifth resistor is connected with the first end of the sixth resistor, the second end of the sixth resistor is connected with the first end of the seventh resistor, and the second end of the seventh resistor is grounded;
the first end of the eighth resistor is connected with the first end of the seventh resistor, the second end of the eighth resistor is connected with the first end of the capacitor, and the second end of the capacitor is connected with the second end of the seventh resistor;
and a connecting node of the eighth resistor and the capacitor is used as an output end of the common-mode voltage generating module.
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