CN111293988B - Audio power amplifier and electronic equipment - Google Patents
Audio power amplifier and electronic equipment Download PDFInfo
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- CN111293988B CN111293988B CN201811642939.2A CN201811642939A CN111293988B CN 111293988 B CN111293988 B CN 111293988B CN 201811642939 A CN201811642939 A CN 201811642939A CN 111293988 B CN111293988 B CN 111293988B
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/26—Modifications of amplifiers to reduce influence of noise generated by amplifying elements
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/34—Negative-feedback-circuit arrangements with or without positive feedback
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2200/00—Indexing scheme relating to amplifiers
- H03F2200/03—Indexing scheme relating to amplifiers the amplifier being designed for audio applications
Abstract
The present disclosure relates to an audio power amplifier and an electronic device, wherein the power amplifier comprises: a pre-operational amplifier; a switch switching assembly; the output module comprises a first output unit and a second output unit which are respectively connected with the output end of the preceding operational amplifier through the switch switching component, and the output end of the first output unit and the output end of the second output unit are respectively connected with the input end of the preceding operational amplifier in a feedback mode and the output end of the second output unit in a feedback mode; the fast establishing auxiliary module is connected with the output end of the preceding operational amplifier through the switch switching component; and the switch controller is connected with the switch switching component and is used for controlling the connection state between the switch switching component and the first output unit, the second output unit and the quick-establishment auxiliary module. The embodiment of the disclosure can effectively eliminate POP noise while realizing audio signal amplification driving.
Description
Technical Field
The present disclosure relates to the field of audio amplification technologies, and in particular, to an audio power amplifier and an electronic device.
Background
During the starting process of the audio power amplifier, the voltage of each node in the circuit goes through an establishing process before entering a stable working state, the audio signal output in the establishing process is uncontrollable and irregular, and the traditional audio power amplifier is directly connected with an external acoustic load device, so that a user can hear a POP (POP noise) when playing audio, and very bad hearing experience is brought to the user.
Disclosure of Invention
In view of this, the present disclosure provides an audio power amplifier and an electronic device, which can effectively eliminate POP noise on the basis of implementing audio signal amplification.
According to a first aspect of the present disclosure, there is provided an audio power amplifier comprising:
a pre-operational amplifier;
a switch switching assembly;
the output module comprises a first output unit and a second output unit which are respectively connected with the output end of the preceding operational amplifier through the switch switching component, the output end of the first output unit and the output end of the second output unit are respectively connected to the input end of the preceding operational amplifier in a feedback mode, and the output end of the second output unit is also used for outputting signals processed by the power amplifier;
the fast establishing auxiliary module is connected with the output end of the preceding operational amplifier through the switch switching component and is used for enabling the second output unit to quickly establish a stable working state when the second output unit is switched on;
and the switch controller is connected with the switch switching component and is used for controlling the connection state between the switch switching component and the first output unit, the second output unit and the quick-establishment auxiliary module.
In some possible embodiments, the pre-operational amplifier comprises a positive input terminal and a negative input terminal, wherein the negative input terminal receives a first input signal of audio, the positive input terminal receives a second input signal of audio,
and the output ends of the first output unit and the second output unit are respectively connected to the negative input end of the preceding stage operational amplifier in a feedback mode.
In some possible embodiments, the switch controller controls the switch switching component to turn on the connection between the pre-operational amplifier and the first output unit, controls the switch switching component to turn off the connection between the pre-operational amplifier and the second output unit, and controls the switch switching component to turn on the connection between the pre-operational amplifier and the fast-setup auxiliary module in a first time range from a time when the audio power amplifier is activated;
and the switch controller controls the switch switching component to turn off the connection between the pre-operational amplifier and the first output unit, controls the switch switching component to turn on the connection between the pre-operational amplifier and the second output unit, and controls the switch switching component to turn on the connection between the pre-operational amplifier and the fast-setup auxiliary module in a second time range after the first time range.
In some possible embodiments, the switch controller controls the switch switching component to turn off the connection between the pre-operational amplifier and the first output unit, controls the switch switching component to turn on the connection between the pre-operational amplifier and the second output unit, and controls the switch switching component to turn off the connection between the pre-operational amplifier and the fast setup auxiliary module in a third time range after the second time range.
In some possible embodiments, the switching assembly includes a first switching unit, a second switching unit, a third switching unit,
the first switch unit is respectively connected with the output end of the preceding operational amplifier and the input end of the first output unit so as to control the connection or disconnection of the preceding operational amplifier and the first output unit;
the second switch unit is respectively connected with the output end of the preceding operational amplifier and the input end of the second output unit so as to control the connection or disconnection of the preceding operational amplifier and the second output unit;
the third switch unit is respectively connected with the output end of the preceding operational amplifier and the quick-establishing auxiliary module so as to control the connection or disconnection of the preceding operational amplifier and the quick-establishing auxiliary module.
In some of the possible embodiments of the present invention,
the output end of the preceding operational amplifier comprises a first positive output end and a second positive output end;
the first switch unit comprises a first field effect transistor, a second field effect transistor, a first switch, a second switch and a third switch;
the first output unit comprises a third field effect transistor and a fourth field effect transistor;
wherein, one end of the first switch is connected with the second positive output end of the preceding operational amplifier, the other end of the first switch is respectively connected with the third end of the second field effect transistor and the first end of the fourth field effect transistor, the first end of the second field effect transistor receives a time sequence control signal sent by the switch controller, the second end of the second field effect transistor is connected with a power supply voltage, the second end of the fourth field effect transistor is connected with the power supply voltage, the third end of the fourth field effect transistor is respectively connected with the output end of the first output unit and the third end of the third field effect transistor,
one end of the second switch is respectively connected with the second positive output end and the first positive output end of the preceding operational amplifier through a capacitor, the other end of the second switch is respectively connected with the third end of the fourth field effect transistor and the third end of the third field effect transistor,
one end of a third switch is connected with the first positive output end of the preceding operational amplifier, the other end of the third switch is respectively connected with the third end of the first field effect transistor and the first end of the third field effect transistor, the first end of the first field effect transistor receives a time sequence control signal sent by the switch controller, the second end of the first field effect transistor is grounded, the second end of the third field effect transistor is grounded, and the third end of the third field effect transistor is respectively connected with the output end of the first unit output unit and the third end of the fourth field effect transistor.
In some possible embodiments, the first field effect transistor and the third field effect transistor are N-type field effect transistors, the second field effect transistor and the fourth field effect transistor are P-type field effect transistors, the first terminal is a gate of the field effect transistor, the second terminal is a source of the field effect transistor, and the third terminal is a drain of the field effect transistor.
In some of the possible embodiments, the first and second,
the output end of the preceding operational amplifier comprises a first positive output end and a second positive output end;
the second switch unit comprises a fifth field effect transistor, a sixth field effect transistor, a fourth switch, a fifth switch and a sixth switch;
the second output unit comprises a seventh field effect transistor and an eighth field effect transistor;
wherein, one end of the fourth switch is connected with the second positive output end of the preceding operational amplifier, the other end of the fourth switch is respectively connected with the third end of the sixth field effect tube and the first end of the fourth field effect tube, the first end of the sixth field effect tube receives the time sequence control signal sent by the switch controller, the second end of the sixth field effect tube is connected with the power supply voltage, the second end of the eighth field effect tube is connected with the power supply voltage, the third end of the eighth field effect tube is respectively connected with the output end of the second output unit and the third end of the seventh field effect tube,
one end of a fifth switch is respectively connected with the second positive output end and the first positive output end of the preceding operational amplifier through a capacitor, the other end of the fifth switch is respectively connected with the third end of the eighth field-effect tube and the third end of the seventh field-effect tube,
one end of a sixth switch is connected with the first positive output end of the preceding operational amplifier, the other end of the sixth switch is respectively connected with the third end of a fifth field-effect tube and the first end of a seventh field-effect tube, the first end of the fifth field-effect tube receives a time sequence control signal sent by the switch controller, the second end of the fifth field-effect tube is connected with the ground voltage, the second end of the seventh field-effect tube is connected with the ground voltage, and the third end of the seventh field-effect tube is respectively connected with the output end of the second unit output unit and the third end of the eighth field-effect tube.
In some possible embodiments, the fifth field effect transistor and the seventh field effect transistor are N-type field effect transistors, the sixth field effect transistor and the eighth field effect transistor are P-type field effect transistors, the first terminal is a gate of the field effect transistor, the second terminal is a source of the field effect transistor, and the third terminal is a drain of the field effect transistor.
In some of the possible embodiments of the present invention,
the output end of the preceding operational amplifier comprises a first positive output end and a second positive output end;
the third switching unit includes a seventh switch and an eighth switch;
the fast establishing auxiliary module comprises a first capacitor, a second capacitor, a first resistor, a second resistor, a first current source, a second current source, a ninth field effect transistor, a tenth field effect transistor, an eleventh field effect transistor, a twelfth field effect transistor and a biaser;
wherein, one end of the seventh switch is connected with the second positive output end of the preceding operational amplifier, the other end of the seventh switch is respectively connected with the first current source, the first capacitor and the third end of the tenth field effect transistor, the other end of the first current source is connected with the power supply voltage, the other end of the first capacitor is connected with the first end of the ninth field effect transistor, the second end of the tenth field effect transistor is connected with the third end of the ninth field effect transistor, the third end of the ninth field effect transistor is connected with the ground voltage,
one end of an eighth switch is connected with the first positive output end of the preceding operational amplifier, the other end of the eighth switch is respectively connected with a second current source, a second capacitor and a third end of a twelfth field-effect tube, the other end of the second current source is connected with the ground voltage, the other end of the second capacitor is connected with the first end of the eleventh field-effect tube, the second end of the twelfth field-effect tube is connected with the third end of the eleventh field-effect tube, the third end of the eleventh field-effect tube is connected with the power supply voltage,
the biaser respectively provides a first bias voltage, a second bias voltage, a third bias voltage and a fourth bias voltage for the first ends of the ninth field effect transistor, the tenth field effect transistor, the eleventh field effect transistor and the twelfth field effect transistor, wherein the first bias voltage is connected with the first end of the ninth field effect transistor through a first resistor, and the third bias voltage is connected with the first end of the eleventh field effect transistor through a second resistor.
In some possible embodiments, the ninth fet and the tenth fet are N-type fets, the eleventh fet and the twelfth fet are P-type fets, the first terminal is a gate of the fet, the second terminal is a source of the fet, and the third terminal is a drain of the fet.
According to a second aspect of the present disclosure, there is provided an electronic device comprising the audio power amplifier of any one of the first aspects of the present disclosure.
The embodiment of the disclosure establishes a stable working state of the circuit by connecting the first output unit with the output end of the preceding operational amplifier, and then switches to connect the second output unit with the output end of the preceding operational amplifier to output the audio signal processed by the power amplifier, thereby effectively reducing the POP noise generated in the starting process of the audio power amplifier, accelerating the speed of establishing the stable working state of the second output unit with the output end of the preceding operational amplifier by quickly establishing the auxiliary module, and reducing the POP noise generated by rebuilding the working state of the circuit.
Other features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.
Fig. 1 shows a block diagram of an audio power amplifier according to an embodiment of the present disclosure.
Fig. 2 illustrates a schematic diagram of timing control signals according to an embodiment of the present disclosure.
Fig. 3 illustrates an internal circuit configuration diagram according to an embodiment of the present disclosure.
Fig. 4 illustrates a schematic diagram of timing control signals according to an embodiment of the present disclosure.
Detailed Description
Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.
It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present invention. Depending on the warning, the word "if" as used herein may be understood as "at 8230; \8230, or" when 8230; \8230, or "in response to a determination", etc.
Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present disclosure. It will be understood by those skilled in the art that the present disclosure may be practiced without some of these specific details. In some instances, methods, means, elements and circuits that are well known to those skilled in the art have not been described in detail so as not to obscure the present disclosure.
The audio power amplifier of the embodiment of the present disclosure may be installed in any electronic device that needs an audio power amplifier, such as a computer, a mobile phone, a landline telephone, a sound, a music player, an earphone, a loudspeaker, and other electronic devices that need an audio power amplifier, for example: messaging devices, game consoles, tablet devices, medical devices, fitness devices, personal digital assistants, etc., the disclosure of which is not intended to be limiting.
Fig. 1 shows a block diagram of an audio power amplifier according to an embodiment of the present disclosure. As shown in fig. 1, the audio power amplifier mainly includes:
a front-stage operational amplifier 100 for performing an audio amplification operation;
a switch switching assembly 200 for performing a switching operation of a switch;
an output module 300, which includes a first output unit 310 and a second output unit 320 respectively connected to the output end of the preceding operational amplifier 100 through the switch switching component 200, and the output end of the first output unit 310 and the output end of the second output unit 320 are also respectively connected to the input end of the preceding operational amplifier 100 in a feedback manner, and the output end of the second output unit is further used for outputting a signal after power amplification processing;
a fast-setup auxiliary module 400 connected to the output terminal of the pre-operational amplifier 100 through the switch switching component 200, for enabling the second output unit to fast establish a stable operating state when the second output unit is turned on;
a switch controller 500 connected to the switch switching assembly 200 and configured to control a connection state between the switch switching assembly 200 and the first output unit 310, the second output unit 320 and the quick setup auxiliary module 400.
The pre-operational amplifier 100 according to the embodiment of the present disclosure may initially perform an amplification process on an input signal, and the type and model of the pre-operational amplifier may be adjusted according to different requirements, which is not particularly limited in the present disclosure.
As shown in fig. 1, the pre-operational amplifier 100 according to the embodiment of the disclosure may include two input terminals, namely a positive input terminal and a negative input terminal, wherein the negative input terminal receives the first input signal VIN of the audio, and the positive input terminal receives the second input signal VIP of the audio, for example, the first input signal and the second input signal may be differential signals with equal amplitudes and opposite phases. The amplification process of the corresponding input signal can be performed by a pre-operational amplifier.
As an example, the present disclosure adopts a differential-to-single-ended amplifier circuit with a negative feedback structure as an embodiment, as shown in fig. 1, the output ends of the first output unit 310 and the second output unit 320 are respectively connected to the negative input end of the previous stage operational amplifier 100 in a feedback manner, a feedback resistor may be further added between the output end of the first output unit and the negative input end of the previous stage operational amplifier, as shown by a resistor Rd in fig. 1, and similarly, a feedback resistor may be further added between the output end of the second output unit and the negative input end of the previous stage operational amplifier, as shown by a resistor R4 in fig. 1, and a resistor may be further provided between the positive input end and the negative input end of the previous stage operational amplifier, as shown by R1 and R2 in fig. 1, and the positive input end of the previous stage operational amplifier is further connected to a resistor, and the other end of the resistor is connected to ground or a common mode voltage, as shown by a resistor R3 in fig. 1. The resistors R1, R2, R3, R4, and Rd may adjust the gain of the audio power amplifier according to the embodiment of the disclosure by adjusting the resistance values of the resistors, and a person skilled in the art may determine the resistance values of the resistors according to the characteristics of the components included in the circuit and the related configuration requirements, which is not specifically limited by the disclosure.
As described above, during the start-up process of the audio power amplifier, the circuit parameters of each node inside the circuit, such as the operating voltage and current of each node, will go through a set-up process before entering a stable operating state, and the audio signal output during the set-up process is uncontrollable and irregular. Therefore, the output module of the embodiment of the present disclosure is provided with the first output unit and the second output unit, and the first output unit is firstly connected to the output terminal of the preceding operational amplifier, and is disconnected after the operating voltage of each node of the circuit is stabilized, the second output unit is changed to be connected to the output terminal of the preceding operational amplifier, and the audio signal processed by the power amplifier is output by the second output unit, and then the output audio signal can be further transmitted to an external acoustic load device, such as the speaker 600, as shown in fig. 1.
In addition, when the first output unit and the preceding operational amplifier are turned on and the operating state of each node in the circuit is stabilized, the first output unit is disconnected from the output terminal of the preceding operational amplifier, and the second output unit is connected to the output terminal of the preceding operational amplifier, during this process, since the components in the second output unit need to be connected to the circuit in which the operating state is established, a new operating state may be re-established for each node in the circuit, and since a large parasitic capacitance exists in the gate of the field-effect transistor, the existence of the parasitic capacitance may affect the re-establishment process and extend the time for each node to establish the stable operating state, thereby outputting POP noise, which is the POP sound generated by transient impact brought by various operations at the moment of power-on and power-off of the audio device and after the power-on is stabilized. Therefore, the fast establishing auxiliary module is arranged to solve the problem, and the fast establishing auxiliary module is connected to the output end of the pre-operational amplifier by controlling the switch switching component. The switch switching component 200 controls the connection timing sequence of the pre-operational amplifier 100, the first output unit and the second output unit, the first output unit can be used for performing feedback operation of signals, when the circuit is stable, namely the output audio is stable and the establishment is completed, the second output unit is switched on, and at this time, a stable audio power amplifier information number can be output. In addition, by introducing the fast-establishment auxiliary module, when the second output unit is connected with the preceding operational amplifier, the second output unit can be enabled to quickly establish stable working states, such as stable direct-current node voltage and branch current.
For convenience of understanding, the first output unit, the second output unit, and the switching operation procedure between the fast setup auxiliary module and the output terminal of the previous stage operational amplifier according to the embodiments of the present disclosure are described in detail below.
As shown in fig. 1, the switching assembly 200 includes a first switching unit S1, a second switching unit S2, and a third switching unit S3. Specifically, the first switch unit S1 is respectively connected to an output terminal of the pre-operational amplifier 100 and an input terminal of the first output unit 310, so as to control the pre-operational amplifier 100 and the first output unit 310 to be turned on or off; the second switch unit S2 is respectively connected to an output terminal of the pre-operational amplifier 100 and an input terminal of the second output unit 320, so as to control the pre-operational amplifier 100 and the second output unit 320 to be turned on or off; the third switching unit S3 is respectively connected to the output terminal of the pre-operational amplifier 100 and the fast setup auxiliary module 400 to control the connection or disconnection of the pre-operational amplifier 100 and the fast setup auxiliary module 400.
Also, the switch controller 500 is further employed in the embodiments of the present disclosure to control each switch unit in the switch switching assembly, for example, the switch controller controls the first switch unit S1, the second switch unit S2, and the third switch unit S3 by sending out timing control signals. Fig. 2 illustrates a schematic diagram of a timing control signal according to an embodiment of the present disclosure, wherein an abscissa represents time and an ordinate represents a level, wherein the level may further include a high level and a low level as illustrated in fig. 2.
As shown in fig. 2, the switch controller controls the first switch unit S1 of the switch switching assembly to turn on the preamplifier 100 and the first output unit 310, controls the second switch unit S2 of the switch switching assembly to turn off the preamplifier 100 and the second output unit 320, and controls the third switch unit S3 of the switch switching assembly to turn on the preamplifier 100 and the fast setup assist module 400 in a first time range from a time point when the audio power amplifier is started up, i.e., a time range from the start of the audio power amplifier to a time point when each node in a circuit composed of the first output unit and the preamplifier completes a stable operation state, such as a time range from 0 to t1 in fig. 2.
Then, the switch controller 500 controls the first switching unit S1 in the switch switching assembly to turn off the pre-operational amplifier 100 and the first output unit 310, controls the second switching unit S2 in the switch switching assembly to turn on the pre-operational amplifier 100 and the second output unit 320, and controls the third switching unit S3 in the switch switching assembly to turn on the pre-operational amplifier 100 and the fast setup assist module 400 in a second time range after the first time range, i.e., from the time when the first output unit and each node in the circuit of the pre-operational amplifier complete the stable operation state to the time when each node in the circuit of the second output unit and the pre-operational amplifier complete the stable operation state, as in the time range of t1 to t2 in fig. 2.
And after the stable working state of each node in the circuit formed by the second output unit and the previous operational amplifier is established, the fast establishment auxiliary module is no longer needed to assist the fast establishment of the working state of each node in the circuit, in order to not increase additional power consumption, the fast establishment auxiliary module can be disconnected from the output end of the previous operational amplifier, that is, the switch controller controls the first switch unit S1 in the switch switching assembly to turn off the previous operational amplifier 100 and the first output unit 310, controls the second switch unit S2 in the switch switching assembly to turn on the previous operational amplifier 100 and the second output unit 320, and controls the third switch unit S3 in the switch switching assembly to turn off the previous operational amplifier 100 and the fast establishment auxiliary module 400 in a third time range after the second time range, such as after time t2 in fig. 2.
The embodiment of the disclosure establishes a stable working state of the circuit by first connecting the first output unit with the output terminal of the preceding operational amplifier, and then switches to connect the second output unit with the output terminal of the preceding operational amplifier to output the audio signal after the power amplifier processing, thereby effectively reducing the POP noise generated in the starting process of the audio power amplifier, accelerating the speed of establishing the stable working state of the second output unit with the output terminal of the preceding operational amplifier by quickly establishing the auxiliary module, and reducing the POP noise generated by the reconstruction of the working state of the circuit.
The embodiment of the present disclosure further provides a structure diagram of an internal circuit of the fast setup auxiliary module, the first output unit, and the second output unit, as shown in fig. 3, fig. 3 shows a structure diagram of an internal circuit according to an embodiment of the present disclosure. The following describes the circuit configuration diagram in detail by taking an example in which the output terminal of the preceding operational amplifier includes a first positive output terminal and a second positive output terminal.
As shown in fig. 3, the first output unit includes a third fet MND and a fourth fet MPD; the first switch unit S1 includes a first fet MN4, a second fet MP4, a first switch S12, a second switch S13, and a third switch S14. And each component included in the first switch unit executes an instruction according to a time sequence control signal sent by the switch controller. Fig. 4 shows a schematic diagram of a timing control signal according to an embodiment of the present disclosure, wherein an abscissa represents time, an ordinate represents a level, wherein as shown in fig. 4, the level may further include a high level and a low level, and t1 and t2 in fig. 4 have the same meaning as t1 and t2 in fig. 2. The values of the time t1 and the time t2 may be determined by those skilled in the art according to the structure and the related configuration of the circuit device, which are not specifically limited in the present disclosure.
One end of the first switch S12 is connected to the second positive output end of the preceding operational amplifier, the other end of the first switch S12 is connected to the third end of the second field-effect transistor MP4 and the first end of the fourth field-effect transistor MPD, and the first end of the second field-effect transistor MP4 receives the timing control signal S11 sent by the switch controller. The second end of the second field effect transistor MP4 is connected to the supply voltage VDD, the second end of the fourth field effect transistor MPD is connected to the supply voltage VDD, and the third end of the fourth field effect transistor MPD is connected to the output end Vod of the first output unit and the third end of the third field effect transistor MND, respectively.
One end of a second switch S13 is connected with the second positive output end and the first positive output end of the preceding operational amplifier through capacitors, wherein the second switch S13 is connected with the second positive output end of the preceding operational amplifier through a capacitor C3, the second switch S13 is connected with the first positive output end of the preceding operational amplifier through a capacitor C4, and the other end of the second switch S13 is connected with the third end of a fourth field-effect tube MPD and the third end of a third field-effect tube MND respectively. The capacitor C3 and the capacitor C4 can stabilize the working state of the circuit and compensate the phase of the signal, and can separate the primary and secondary poles of the loop and compensate the effect of stable frequency response of the loop.
One end of the third switch S14 is connected to the first positive output end of the preceding operational amplifier 100, the other end of the third switch S14 is connected to the third end of the first field-effect tube MN4 and the first end of the third field-effect tube MND, respectively, the first end of the first field-effect tube MN4 receives the timing control signal S15 sent by the switch controller, the ground voltage VSS at the second end of the first field-effect tube MN4, the ground voltage VSS at the second end of the third field-effect tube MND, and the third end of the third field-effect tube MND is connected to the output end Vod of the first unit output unit and the third end of the fourth field-effect tube MPD, respectively.
The first field effect transistor MN4 and the third field effect transistor MND may be N-type field effect transistors, the second field effect transistor MP4 and the fourth field effect transistor MPD may be P-type field effect transistors, the first end may be a gate of a field effect transistor, the second end may be a source of a field effect transistor, and the third end may be a drain of a field effect transistor. And the first switch, the second switch and the third switch may be switching devices such as diodes, relays and the like.
As shown in fig. 3, the second output unit includes a seventh fet MNOUT and an eighth fet MPOUT; the second switch unit S2 includes a fifth fet MN3, a sixth fet MP3, a fourth switch S22, a fifth switch S23, and a sixth switch S24. And each component included in the second switch unit executes an instruction according to a time sequence control signal sent by the switch controller.
One end of the fourth switch S22 is connected to the second positive output end of the preceding operational amplifier, the other end of the fourth switch S22 is connected to the third end of the sixth field effect transistor MP3 and the first end of the fourth field effect transistor MPOUT, respectively, the first end of the sixth field effect transistor MP3 receives the timing control signal S21 sent by the switch controller, as shown in the timing control signal S21 shown in fig. 4, the second end of the sixth field effect transistor MP3 is connected to the supply voltage VDD, the second end of the eighth field effect transistor MPOUT is connected to the supply voltage VDD, and the third end of the eighth field effect transistor MPOUT is connected to the output Vo of the second output unit and the third end of the seventh field effect transistor MNOUT, respectively.
One end of a fifth switch S23 is connected to the second positive output end and the first positive output end of the pre-operational amplifier through capacitors, wherein the fifth switch S23 is connected to the second positive output end of the pre-operational amplifier through a capacitor C3, the fifth switch S23 is connected to the first positive output end of the pre-operational amplifier through a capacitor C4, and the other end of the fifth switch S23 is connected to the third end of the eighth fet MPOUT and the third end of the seventh fet MNOUT, respectively, wherein the capacitors C3 and C4 can stabilize the operating state of the circuit and compensate the phase of the signal during the operational amplifier processing, and can separate the loop primary and secondary poles and compensate the effect of stabilizing the loop frequency response.
One end of a sixth switch S24 is connected to the first positive output end of the preceding operational amplifier, the other end of the sixth switch S24 is connected to the third end of the fifth field-effect tube MN3 and the first end of the seventh field-effect tube MNOUT, respectively, the first end of the fifth field-effect tube MN3 receives the timing control signal S25 sent by the switch controller, the second ground voltage VSS of the fifth field-effect tube MN3, the second end ground voltage VSS of the seventh field-effect tube MNOUT, and the third end of the seventh field-effect tube MNOUT is connected to the output end Vo of the second unit output unit and the third end of the eighth field-effect tube MPOUT, respectively.
The fifth field effect transistor MN3 and the seventh field effect transistor MNOUT may be N-type field effect transistors, the sixth field effect transistor MP3 and the eighth field effect transistor MPOUT may be P-type field effect transistors, the first end may be a gate of a field effect transistor, the second end may be a source of a field effect transistor, and the third end may be a drain of a field effect transistor. And the fourth switch, the fifth switch and the sixth switch may be switching devices such as diodes, relays and the like.
As shown in fig. 3, the fast setup auxiliary module includes a first capacitor C1, a second capacitor C2, a first resistor R5, a second resistor R6, a first current source I1, a second current source I2, a ninth fet MN1, a tenth fet MN2, an eleventh fet MP1, a twelfth fet MP2, and a bias device; the third switching unit S3 includes a seventh switch S31 and an eighth switch S32.
Wherein, one end of the seventh switch S31 is connected with the second positive output end of the preceding operational amplifier, the other end of the seventh switch S31 is respectively connected with the third ends of the first current source I1, the first capacitor C1 and the tenth field effect transistor MN2, the other end of the first current source I1 is connected with the power supply voltage VDD, the other end of the first capacitor C1 is connected with the first end of the ninth field effect transistor MN1, the second end of the tenth field effect transistor MN2 is connected with the third end of the ninth field effect transistor MN1, the third end of the ninth field effect transistor MN1 is grounded voltage VSS,
one end of an eighth switch S32 is connected to the first positive output end of the preceding operational amplifier, the other end of the eighth switch S32 is connected to the third ends of the second current source I2, the second capacitor C2 and the twelfth fet MP2, respectively, the other end of the second current source I2 is grounded to the voltage VSS, the other end of the second capacitor C2 is connected to the first end of the eleventh fet MP1, the second end of the twelfth fet MP2 is connected to the third end of the eleventh fet MP1, and the third end of the eleventh fet MP1 is connected to the supply voltage VDD.
The biaser respectively provides a first bias voltage Vbn, a second bias voltage Vbn2, a third bias voltage Vbp and a fourth bias voltage Vbp2 for the first ends of the ninth field-effect tube MN1, the tenth field-effect tube MN2, the eleventh field-effect tube MP1 and the twelfth field-effect tube MP 2. In order to couple the gate voltage of the seventh fet MNOUT and the gate voltage of the eleventh fet MP1, an RC circuit may be provided to implement ac coupling, such as a resistor R6 shown in fig. 3 and the capacitor C2, and an RC circuit may also be provided to couple the gate voltage of the eighth fet MPOUT and the gate voltage of the ninth fet MN1, such as a resistor R5 shown in fig. 3 and the capacitor C1, where one end of the resistor R5 receives the first bias voltage Vbn, the other end of the resistor R5 is connected to the gate of the MN1, one end of the resistor R6 receives the third bias voltage Vbp, and the other end of the resistor R6 is connected to the gate of the MP 1.
The ninth field-effect tube MN1 and the tenth field-effect tube MN2 may be N-type field-effect tubes, the eleventh field-effect tube MP1 and the twelfth field-effect tube MP2 may be P-type field-effect tubes, the first end may be a gate of the field-effect tube, the second end may be a source of the field-effect tube, and the third end may be a drain of the field-effect tube. And the seventh switch, the eighth switch and the ninth switch may be switching devices such as diodes, relays and the like.
In the above-described embodiment, that is, in the circuit shown in fig. 3, the components in each switch unit execute the command according to the timing control signal shown in fig. 4, and as shown in fig. 4, the timing control signal includes the high level and the low level, and in the embodiment of the present disclosure, the switches S12, S13, S14, S22, S23, S24 are set to execute the close command at the high level and execute the open command at the low level, and as can be seen from the characteristics of the field effect transistors, when the P-type field effect transistors are used as the switches, the gates of the P-type field effect transistors execute the open command (i.e., turn on the circuits connected to the source and the drain) when the high level is received, the gates of the P-type field effect transistors execute the close command (i.e., turn on the circuits connected to the source and the drain) when the low level is received, and when the N-type field effect transistors are used as the switches, the gates of the N-type field effect transistors execute the open command (i.e., turn on the circuits connected to the source and the drain) when the low level is received, and the gates of the MP3 and the MN are not connected to execute the open command (i.e., the high level) when the switches S14 and the switches are received, and the switches are not to execute the control commands, and the switches S23, and the switches may execute the high level when the switches are received, and the switches are used as other embodiments, and execute the specific control commands, and the switches S14, and the switches are executed, and the switches.
In the embodiment of the present disclosure, the fast setup auxiliary module is mainly used to accelerate the speed of setting up the stable operating state between the second output unit and the output terminal of the preceding operational amplifier, and thereby reduce the POP noise output, and the principle of this process is described in detail below.
As shown in fig. 4, in the time range from 0 to t1, the gate of the fet MP3 in the second output unit in fig. 3 always receives a low level (the circuit connecting its source and drain is turned on), so the gate voltage of the fet MPOUT is VDD, and the gate of the fet MN3 always receives a high level (the circuit connecting its source and drain is turned on), so the gate voltage of the fet MNOUT is the ground voltage VSS, which can be regarded as 0 v.
Until time t1, the gate of the field effect transistor MP3 receives a high level, and the circuit connecting the source and the drain thereof is turned off, the switch S22 receives a high level, and the gate of the MPOUT is connected to the output terminal of the previous operational amplifier, and the two ends of the switch S22 are before the gate of the MPOUT and the output terminal of the previous operational amplifier are connected, and both belong to different circuits, so that the voltages at the two ends of the switch S22 are not equal, and therefore, the two-end circuits have a process of quickly sharing charges, so that the voltage at the end of the switch S22 connected to the gate of the MPOUT rapidly jumps downwards, the voltage at the other end of the switch S22 rapidly jumps upwards, and the end of the voltage jump upwards jumps the gate voltage of the MN1 upwards through an ac coupling circuit formed by the circuits of the switch S31, the capacitor C1 and the resistor R5, and then the channel current between the drain and the source of the MN1 is increased, and the increase of the current can accelerate the discharge of charges in the parasitic capacitor in the gate of the MPOUT, and then the speed of the stable operation state of the gate voltage of the MPOUT is accelerated.
Similarly, until time t1, the gate of the fet MN3 receives a low level, and the circuit with its source and drain connected is turned off, the switch S24 receives a high level, and turns on the gate of MNOUT and the output of the pre-operational amplifier, and the voltages at the two ends of the switch S24 are different, so that the circuits at the two ends have a process of quickly sharing charges, that is, the gate voltage of MNOUT jumps up quickly, the voltage at the other end of the switch S24 jumps down quickly, and the one end of the voltage jump down jumps down by the ac coupling circuit formed by the circuit of the switch S32, the capacitor C2, and the resistor R6, so as to increase the gate voltage of MP1, and then increase the channel current of MP1, that is, the current between the source and the drain, and this increase of the current can accelerate the charge compensation in the parasitic capacitor in the gate of MNOUT, and then accelerate the speed of the gate voltage of MNOUT entering the stable operating state, that is, and the speed of establishing the stable operating state of the output unit and the output of the pre-operational amplifier is accelerated, and the POP noise generated by the circuit operating state reconstruction is reduced.
Therefore, the auxiliary module for fast establishing of the embodiment of the disclosure can solve the technical problem that the parasitic capacitance exists in the field effect transistor in the working circuit, so that the time for each node in the circuit to establish a stable working state is prolonged, and the generation of POP noise is reduced.
In summary, in the embodiment of the present disclosure, the first output unit is first connected to the output terminal of the preceding operational amplifier to establish the stable operating state of the circuit, and then the second output unit is connected to the output terminal of the preceding operational amplifier to output the audio signal after the power amplifier processing, so that POP noise generated during the start-up process of the audio power amplifier can be effectively reduced, the speed of establishing the stable operating state between the second output unit and the output terminal of the preceding operational amplifier is increased by quickly establishing the auxiliary module, and POP noise generated by the reconstruction of the operating state of the circuit is reduced.
The disclosed embodiment also provides an electronic device configured to include any one of the audio power amplifiers in the above embodiments, such as a computer, a mobile phone, a landline phone, a stereo, a music player, an earphone, a loudspeaker, and other electronic devices requiring an audio power amplifier, for example: messaging devices, game consoles, tablet devices, medical devices, fitness devices, personal digital assistants, and the like.
Having described embodiments of the present disclosure, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein were chosen in order to best explain the principles of the embodiments, the practical application, or technical improvements to the techniques in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Claims (10)
1. An audio power amplifier, comprising:
a pre-operational amplifier;
a switch switching assembly;
the output module comprises a first output unit and a second output unit which are respectively connected with the output end of the preceding operational amplifier through the switch switching component, the output end of the first output unit and the output end of the second output unit are respectively connected to the input end of the preceding operational amplifier in a feedback way, and the output end of the second output unit is also used for outputting signals processed by the power amplifier;
the fast establishing auxiliary module is connected with the output end of the preceding operational amplifier through the switch switching component and is used for enabling the second output unit to quickly establish a stable working state when the second output unit is switched on;
a switch controller connected to the switch switching assembly and configured to control a connection state between the switch switching assembly and the first output unit, the second output unit, and the fast setup auxiliary module;
in a first time range from a time when the audio power amplifier is started, the switch controller controls the switch switching component to turn on the connection between the pre-operational amplifier and the first output unit, controls the switch switching component to turn off the connection between the pre-operational amplifier and the second output unit, and controls the switch switching component to turn on the connection between the pre-operational amplifier and the fast setup auxiliary module;
and the switch controller controls the switch switching component to turn off a connection between the pre-operational amplifier and the first output unit, controls the switch switching component to turn on a connection between the pre-operational amplifier and the second output unit, and controls the switch switching component to turn on a connection between the pre-operational amplifier and the fast-setup auxiliary module in a second time range after the first time range;
the switch controller controls the switch switching component to turn off the connection between the pre-operational amplifier and the first output unit, controls the switch switching component to turn on the connection between the pre-operational amplifier and the second output unit, and controls the switch switching component to turn off the connection between the pre-operational amplifier and the fast setup auxiliary module in a third time range after the second time range.
2. The audio power amplifier of claim 1, wherein the pre-operational amplifier comprises a positive input terminal and a negative input terminal, wherein the negative input terminal receives a first input signal of audio, the positive input terminal receives a second input signal of audio,
and the output ends of the first output unit and the second output unit are respectively connected to the negative input end of the preceding stage operational amplifier in a feedback mode.
3. The audio power amplifier of any of claims 1-2, wherein the switching assembly comprises a first switching unit, a second switching unit, a third switching unit,
the first switch unit is respectively connected with the output end of the preceding operational amplifier and the input end of the first output unit so as to control the connection or disconnection of the preceding operational amplifier and the first output unit;
the second switch unit is respectively connected with the output end of the preceding operational amplifier and the input end of the second output unit so as to control the connection or disconnection of the preceding operational amplifier and the second output unit;
the third switch unit is respectively connected with the output end of the preceding operational amplifier and the quick-establishing auxiliary module so as to control the connection or disconnection of the preceding operational amplifier and the quick-establishing auxiliary module.
4. Audio power amplifier according to claim 3,
the output end of the preceding operational amplifier comprises a first positive output end and a second positive output end;
the first switch unit comprises a first field effect transistor, a second field effect transistor, a first switch, a second switch and a third switch;
the first output unit comprises a third field effect transistor and a fourth field effect transistor;
wherein, one end of the first switch is connected with the second positive output end of the preceding operational amplifier, the other end of the first switch is respectively connected with the third end of the second field effect tube and the first end of the fourth field effect tube, the first end of the second field effect tube receives the time sequence control signal sent by the switch controller, the second end of the second field effect tube is connected with the power supply voltage, the second end of the fourth field effect tube is connected with the power supply voltage, the third end of the fourth field effect tube is respectively connected with the output end of the first output unit and the third end of the third field effect tube,
one end of the second switch is respectively connected with the second positive output end and the first positive output end of the preceding operational amplifier through a capacitor, the other end of the second switch is respectively connected with the third end of the fourth field effect transistor and the third end of the third field effect transistor,
one end of a third switch is connected with the first positive output end of the preceding operational amplifier, the other end of the third switch is respectively connected with the third end of the first field effect tube and the first end of the third field effect tube, the first end of the first field effect tube receives a time sequence control signal sent by the switch controller, the second end of the first field effect tube is grounded, the second end of the third field effect tube is connected with the ground voltage, and the third end of the third field effect tube is respectively connected with the output end of the first unit output unit and the third end of the fourth field effect tube.
5. The audio power amplifier of claim 4, wherein the first and third FETs are NFETs, the second and fourth FETs are PFETs, the first terminal is a gate of the FETs, the second terminal is a source of the FETs, and the third terminal is a drain of the FETs.
6. Audio power amplifier according to claim 3,
the output end of the preceding operational amplifier comprises a first positive output end and a second positive output end;
the second switch unit comprises a fifth field effect transistor, a sixth field effect transistor, a fourth switch, a fifth switch and a sixth switch;
the second output unit comprises a seventh field effect transistor and an eighth field effect transistor;
wherein, one end of the fourth switch is connected with the second positive output end of the preceding operational amplifier, the other end of the fourth switch is respectively connected with the third end of the sixth field effect tube and the first end of the fourth field effect tube, the first end of the sixth field effect tube receives the time sequence control signal sent by the switch controller, the second end of the sixth field effect tube is connected with the power supply voltage, the second end of the eighth field effect tube is connected with the power supply voltage, the third end of the eighth field effect tube is respectively connected with the output end of the second output unit and the third end of the seventh field effect tube,
one end of a fifth switch is respectively connected with the second positive output end and the first positive output end of the preceding operational amplifier through one end of a capacitor, the other end of the fifth switch is respectively connected with the third end of the eighth field-effect tube and the third end of the seventh field-effect tube,
one end of a sixth switch is connected with the first positive output end of the preceding operational amplifier, the other end of the sixth switch is respectively connected with the third end of a fifth field effect transistor and the first end of a seventh field effect transistor, the first end of the fifth field effect transistor receives a time sequence control signal sent by the switch controller, the second end of the fifth field effect transistor is connected with the ground voltage, the second end of the seventh field effect transistor is connected with the ground voltage, and the third end of the seventh field effect transistor is respectively connected with the output end of the second unit output unit and the third end of the eighth field effect transistor.
7. The audio power amplifier of claim 6, wherein the fifth and seventh fets are N-fets, the sixth and eighth fets are P-fets, the first terminal is a gate of the fet, the second terminal is a source of the fet, and the third terminal is a drain of the fet.
8. Audio power amplifier according to claim 3,
the output end of the preceding operational amplifier comprises a first positive output end and a second positive output end;
the third switching unit includes a seventh switch and an eighth switch;
the fast establishing auxiliary module comprises a first capacitor, a second capacitor, a first resistor, a second resistor, a first current source, a second current source, a ninth field effect transistor, a tenth field effect transistor, an eleventh field effect transistor, a twelfth field effect transistor and a biaser;
wherein, one end of the seventh switch is connected with the second positive output end of the preceding operational amplifier, the other end of the seventh switch is respectively connected with the first current source, the first capacitor and the third end of the tenth field effect transistor, the other end of the first current source is connected with the power supply voltage, the other end of the first capacitor is connected with the first end of the ninth field effect transistor, the second end of the tenth field effect transistor is connected with the third end of the ninth field effect transistor, the third end of the ninth field effect transistor is connected with the ground voltage,
one end of an eighth switch is connected with the first positive output end of the preceding operational amplifier, the other end of the eighth switch is respectively connected with a second current source, a second capacitor and a third end of a twelfth field-effect tube, the other end of the second current source is connected with the ground voltage, the other end of the second capacitor is connected with the first end of the eleventh field-effect tube, the second end of the twelfth field-effect tube is connected with the third end of the eleventh field-effect tube, the third end of the eleventh field-effect tube is connected with the power supply voltage,
the biaser respectively provides a first bias voltage, a second bias voltage, a third bias voltage and a fourth bias voltage for the first ends of the ninth field effect transistor, the tenth field effect transistor, the eleventh field effect transistor and the twelfth field effect transistor, wherein the first bias voltage is connected with the first end of the ninth field effect transistor through a first resistor, and the third bias voltage is connected with the first end of the eleventh field effect transistor through a second resistor.
9. The audio power amplifier of claim 8, wherein the ninth fet and the tenth fet are N-fets, the eleventh fet and the twelfth fet are P-fets, the first terminal is a gate of the fet, the second terminal is a source of the fet, and the third terminal is a drain of the fet.
10. An electronic device comprising an audio power amplifier according to any of claims 1-9.
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| CN202121759U (en) * | 2011-07-01 | 2012-01-18 | 四川和芯微电子股份有限公司 | Pop noise suppression circuit |
| CN105048980B (en) * | 2015-08-18 | 2018-09-18 | 矽力杰半导体技术(杭州)有限公司 | A kind of D audio frequency amplifier |
| KR101742729B1 (en) * | 2016-02-22 | 2017-06-02 | (주)에프씨아이 | High Linearity Inductorless LNA |
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