CN210274516U - Audio amplifying circuit and playback apparatus - Google Patents
Audio amplifying circuit and playback apparatus Download PDFInfo
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- CN210274516U CN210274516U CN201922357764.7U CN201922357764U CN210274516U CN 210274516 U CN210274516 U CN 210274516U CN 201922357764 U CN201922357764 U CN 201922357764U CN 210274516 U CN210274516 U CN 210274516U
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H11/00—Networks using active elements
- H03H11/02—Multiple-port networks
- H03H11/04—Frequency selective two-port networks
- H03H11/12—Frequency selective two-port networks using amplifiers with feedback
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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
Abstract
The utility model provides an audio frequency amplifier circuit and playback devices, include: a player, a comparator, a digital circuit, a weighted adder, and a filter; one path of original audio signal passes through the filter to obtain a filtering signal; the other path of original audio signal is added with the filtering signal in a weighting way through the weighting adder to obtain a weighted addition signal; the weighted addition signal passes through the comparator, the digital circuit and the player in sequence to output an audio signal. The utility model discloses an audio frequency amplifier circuit carries out the feedforward through the signal to getting into comparator, digital circuit and handles to improve the linearity of signal, improve audio signal's quality.
Description
Technical Field
The utility model relates to an integrated circuit technical field especially relates to an audio amplifier circuit and playback devices.
Background
The existing audio amplifying circuit generally adopts two-stage filtering processing, wherein a filtering device adopts a CMOS device, then a signal after filtering is converted into a digital signal through a CMP digital circuit, and finally an audio signal is output by a player.
However, the CMOS device is a voltage-controlled device, and after the original audio signal is filtered twice, harmonic interference signals are doped, so that the linearity of the filtered signal is degraded, and the quality of the finally output audio signal is affected.
SUMMERY OF THE UTILITY MODEL
The utility model provides an audio frequency amplifier circuit and playback apparatus carries out feedforward through the signal to getting into comparator, digital circuit and handles to improve the linearity of signal, improve audio signal's quality.
In a first aspect, an embodiment of the present invention provides an audio amplifying circuit, including: a player, a comparator, a digital circuit, a weighted adder, and a filter; after the first path of original audio signal passes through the filter, a filtering signal is obtained; the second path of original audio signal is added with the filtering signal in a weighting way through the weighting adder to obtain a weighted addition signal; the weighted addition signal passes through the comparator, the digital circuit and the player in sequence to output an audio signal.
In one possible design, the weighted adder includes: the circuit comprises a first resistor, a second resistor, a third resistor and a fourth resistor;
one end of the first resistor is connected with the first output end of the last-order filter, and one end of the second resistor is connected with the positive output end of the second path of original audio signals; the other end of the first resistor and the other end of the second resistor are both connected to a first input end of an integrated circuit formed by the comparator and the digital circuit;
one end of the third resistor is connected with the second output end of the last-order filter, and one end of the fourth resistor is connected with the negative output end of the second path of original audio signals; the other end of the third resistor and the other end of the fourth resistor are both connected to a second input end of an integrated circuit formed by the comparator and the digital circuit.
In one possible design, the weighted adder includes: the first switch capacitor, the second switch capacitor, the third switch capacitor and the fourth switch capacitor;
one end of the first switch capacitor is connected with the first output end of the last-order filter, and one end of the second switch capacitor is connected with the positive output end of the second path of original audio signal; the other end of the first switch capacitor and the other end of the second switch capacitor are both connected to a first input end of an integrated circuit formed by the comparator and the digital circuit;
one end of the third switched capacitor is connected with the second output end of the last-stage filter, and one end of the fourth switched capacitor is connected with the negative output end of the second path of original audio signal; the other end of the third switch capacitor and the other end of the fourth switch capacitor are both connected to a second input end of an integrated circuit formed by the comparator and the digital circuit.
In one possible design, further comprising: a first buffer and a second buffer;
the positive output end of the second path of original audio signal is connected with one end of the first buffer, and the other end of the first buffer is connected with the weighting adder; the negative output end of the second path of original audio signal is connected with one end of the second buffer, and the other end of the second buffer is connected with the weighting adder; after the second path of original audio signal passes through the first buffer and the second buffer, the second path of original audio signal is weighted and added with the filtering signal through the weighting adder to obtain a weighted and added signal.
In one possible design, when the number of the filters is N, and N is a natural number greater than 1, the filters are sequentially connected in series to form an N-order filter.
In one possible design, the filter includes: the operational amplifier, the first capacitor and the second capacitor;
the positive input end of the operational amplifier forms the positive input end of the filter, the negative input end of the operational amplifier forms the negative input end of the filter, the first output end of the operational amplifier forms the first output end of the filter, and the second output end of the operational amplifier forms the second output end of the filter; one end of the first capacitor is connected to the positive input end of the operational amplifier, and the other end of the first capacitor is connected to the first output end of the operational amplifier; one end of the second capacitor is connected to the negative input end of the operational amplifier, and the other end of the second capacitor is connected to the second output end of the operational amplifier.
In one possible design, the firstiThe order filter includes: a third capacitor, a fifth resistor, a fourth capacitor and a sixth resistor;
one end of the third capacitor is connected to the firsti-a positive input terminal of an order-1 filter, the other terminal of the third capacitor being connected to one terminal of the fifth resistor, the other terminal of the fifth resistor being connected to the second terminal of the third resistori-a second output of the order 1 filter;
one end of the fourth capacitor is connected to the firsti-a negative input terminal of a filter of order 1, the other terminal of said fourth capacitor being connected to one terminal of said sixth resistor, the other terminal of said sixth resistor being connected to said second terminali-a first output of a filter of order 1; wherein the content of the first and second substances,ithe value range of (a) is 2, 3, …, N.
In one possible design, the firstiThe order filter includes: a third capacitor, a fifth switched capacitor, a fourth capacitor and a sixth switched capacitor;
one end of the third capacitor is connected to the firsti-a positive input terminal of an order-1 filter, the other terminal of the third capacitor being connected to one terminal of the fifth switched capacitor, the other terminal of the fifth switched capacitor being connected to the third switchi-a second output of the order 1 filter;
one end of the fourth capacitor is connected to the firsti-a negative input of a filter of order 1, the other terminal of said fourth capacitor being connected to one terminal of said sixth switched capacitor, the other terminal of said sixth switched capacitor being connected to said second switchi-a first output of a filter of order 1; wherein the content of the first and second substances,iis gotThe range of values is 2, 3, …, N.
In one possible design, the third capacitor, the fourth capacitor, and theiThe capacitance values of the first capacitor and the second capacitor of the 1 st order filter are the same.
In a second aspect, an embodiment of the present invention provides a playback device, including the audio amplification circuit according to any one of the first aspect.
The utility model provides an audio frequency amplifying circuit and playing device, through dividing original audio signal into two ways, original audio signal gets the filtering signal after passing through the wave filter all the way; the other path of original audio signal is added with the filtering signal in a weighting way through a weighting adder to obtain a weighted addition signal; the weighted addition signal passes through the comparator, the digital circuit and the player in sequence to output an audio signal. Therefore, the linearity of the filtered signal can be improved by using the original audio signal of the other path, and the quality of the output audio signal is improved by performing feedforward processing on the signal entering the comparator and the digital circuit.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.
Fig. 1 is a schematic structural diagram of an audio amplifier circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of an audio amplifier circuit according to a second embodiment of the present invention;
fig. 3 is a schematic structural diagram of an audio amplifier circuit according to a third embodiment of the present invention;
fig. 4 is a schematic structural diagram of an audio amplifier circuit according to a fourth embodiment of the present invention;
fig. 5 is a schematic structural diagram of an audio amplifier circuit according to a fifth embodiment of the present invention.
With the foregoing drawings in mind, certain embodiments of the disclosure have been shown and described in more detail below. These drawings and written description are not intended to limit the scope of the disclosed concepts in any way, but rather to illustrate the concepts of the disclosure to those skilled in the art by reference to specific embodiments.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The technical solution of the present invention will be described in detail with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.
The existing audio amplifying circuit generally adopts two-stage filtering processing, wherein a filter device adopts a CMOS device, then a signal after filtering is converted into a digital signal through a comparator and a digital circuit, and finally an audio signal is output by a player.
However, the CMOS device is a voltage-controlled device, and after the original audio signal is filtered twice, harmonic interference signals are doped, so that the linearity of the filtered signal is degraded, and the quality of the finally output audio signal is affected.
In view of the above, the present invention is directed to provide an audio amplifier circuit, which performs feedforward processing on signals entering a comparator and a digital circuit, thereby improving the linearity of the signals and improving the quality of the audio signals.
The following describes the technical solution of the present invention and how to solve the above technical problems with specific embodiments. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments. Embodiments of the present invention will be described below with reference to the accompanying drawings.
Example one
Fig. 1 is a schematic structural diagram of an audio amplifier circuit according to an embodiment of the present invention, as shown in fig. 1, the audio amplifier circuit in this embodiment may include: a player, a comparator, a digital circuit, a weighted adder, and a filter; after a first path of original audio signal passes through a filter, a filtering signal is obtained; weighting and adding the second path of original audio signal and the filtering signal through a weighting adder to obtain a weighted addition signal; the weighted addition signal passes through the comparator, the digital circuit and the player in sequence to output an audio signal.
Specifically, referring to fig. 1, the positive input terminal of the first-stage filter receives the positive signal Vip of the first audio signal, and the negative input terminal of the first-stage filter receives the negative signal Vin of the first audio signal. The reference terminals of the first-order filter and the second-order filter receive a reference voltage signal Vcom. Taking a two-order filter as an example, the first-order filter and the second-order filter are connected in series, wherein a positive output end of the first-order filter is connected to a positive input end of the second-order filter, and a negative output end of the first-order filter is connected to a negative input end of the second-order filter. The positive output of the second order filter is connected to the first input port of the first weighted adder and the negative output of the second order filter is connected to the first input port of the second weighted adder. The second input port of the first weighted adder receives the positive signal Vip of the second audio signal, and the second input port of the second weighted adder receives the negative signal Vin of the second audio signal. The output end of the first weighting adder is connected to the first input end of the integrated circuit formed by the comparator and the digital circuit, and the output end of the second weighting adder is connected to the second input end of the integrated circuit formed by the comparator and the digital circuit. The output end of the integrated circuit formed by the comparator and the digital circuit is connected with the player.
In the present embodiment, a second-order filter is taken as an example for detailed description, but the number of filters in the circuit is not limited. When the number of the filters is N and N is a natural number greater than 1, the filters are sequentially connected in series to form an N-order filter.
In this embodiment, an original audio signal is divided into two paths, and one path of original audio signal passes through a filter to obtain a filtered signal; the other path of original audio signal is added with the filtering signal in a weighting way through a weighting adder to obtain a weighted addition signal; the weighted addition signal passes through a comparator, a digital circuit and a player in sequence to output an audio signal. Therefore, the linearity of the filtered signal can be improved by using the original audio signal of the other path, and the quality of the output audio signal is improved by performing feedforward processing on the signal entering the comparator and the digital circuit.
Example two
Fig. 2 is a schematic structural diagram of an audio amplifying circuit according to a second embodiment of the present invention, as shown in fig. 2, the audio amplifying circuit in this embodiment may include: a player, a comparator, a digital circuit, a weighted adder, and a filter; after a first path of original audio signal passes through a filter, a filtering signal is obtained; weighting and adding the second path of original audio signal and the filtering signal through a weighting adder to obtain a weighted addition signal; the weighted addition signal passes through the comparator, the digital circuit and the player in sequence to output an audio signal. The weighted adder comprises a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4.
Specifically, referring to fig. 2, a positive signal Vip of the first audio signal is connected to the positive input terminal of the first-stage filter, and a negative signal Vin of the first audio signal is connected to the negative input terminal of the first-stage filter. The reference terminals of the first-order filter and the second-order filter receive a reference voltage signal Vcom. Taking a two-stage filter as an example, the first-stage filter and the second-stage filter are connected in series, wherein one end of the first resistor R1 is connected to the first output terminal of the last-stage filter, and one end of the second resistor R2 is connected to the positive output terminal of the second original audio signal; the other end of the first resistor R1 and the other end of the second resistor R2 are both connected to a first input end of an integrated circuit formed by the comparator and the digital circuit; one end of the third resistor R3 is connected with the second output end of the last-stage filter, and one end of the fourth resistor R4 is connected with the negative output end of the second path of original audio signals; the other end of the third resistor R3 and the other end of the fourth resistor R4 are both connected to a second input end of the integrated circuit formed by the comparator and the digital circuit. The output end of the integrated circuit formed by the comparator and the digital circuit is connected with the player.
It should be noted that the present embodiment does not limit specific resistance values of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4. The person skilled in the art can adjust the weighted addition ratio of the two audio signals by setting the resistances of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4.
In an alternative embodiment, a first buffer and a second buffer may also be provided in the audio amplification circuit. The positive output end of the second path of original audio signal is connected with one end of a first buffer, and the other end of the first buffer is connected with a first weighting adder; the negative output end of the second path of original audio signal is connected with one end of a second buffer, and the other end of the second buffer is connected with a second weighting adder; after the second path of original audio signal passes through the first buffer and the second buffer, the second path of original audio signal is weighted and added with the filtering signal through a weighting adder to obtain a weighted addition signal.
In this embodiment, the influence of the digital circuit on the preceding stage circuit can be avoided by adding the buffer.
In this embodiment, an original audio signal is divided into two paths, and one path of original audio signal passes through a filter to obtain a filtered signal; the other path of original audio signal is added with the filtering signal in a weighting way through a weighting adder to obtain a weighted addition signal; the weighted addition signal passes through a comparator, a digital circuit and a player in sequence to output an audio signal. Therefore, the linearity of the filtered signal can be improved by using the original audio signal of the other path, and the quality of the output audio signal is improved by performing feedforward processing on the signal entering the comparator and the digital circuit.
EXAMPLE III
Fig. 3 is a schematic structural diagram of an audio amplifying circuit according to a third embodiment of the present invention, and as shown in fig. 3, the audio amplifying circuit in this embodiment may include: a player, a comparator, a digital circuit, a weighted adder, and a filter; after a first path of original audio signal passes through a filter, a filtering signal is obtained; weighting and adding the second path of original audio signal and the filtering signal through a weighting adder to obtain a weighted addition signal; the weighted addition signal passes through the comparator, the digital circuit and the player in sequence to output an audio signal. The weighted adder comprises a first switched capacitor C1, a second switched capacitor C2, a third switched capacitor C3 and a fourth switched capacitor C4.
Specifically, referring to fig. 3, a positive signal Vip of the first audio signal is connected to the positive input terminal of the first-stage filter, and a negative signal Vin of the first audio signal is connected to the negative input terminal of the first-stage filter. Taking a two-order filter as an example, the first-order filter and the second-order filter are connected in series, wherein a positive output end of the first-order filter is connected to a positive input end of the second-order filter, and a negative output end of the first-order filter is connected to a negative input end of the second-order filter. One end of the first switched capacitor C1 is connected with the first output end of the last-stage filter, and one end of the second switched capacitor C2 is connected with the positive output end of the second original audio signal; the other end of the first switched capacitor C1 and the other end of the second switched capacitor C2 are both connected to a first input end of an integrated circuit formed by a comparator and a digital circuit; one end of the third switch capacitor C3 is connected with the second output end of the last-stage filter, and one end of the fourth switch capacitor C4 is connected with the negative output end of the second path of original audio signals; the other end of the third switch capacitor C3 and the other end of the fourth switch capacitor C4 are both connected to a second input end of the integrated circuit formed by the comparator and the digital circuit. The output end of the integrated circuit formed by the comparator and the digital circuit is connected with the player.
It should be noted that the present embodiment does not limit specific capacitance values of the first switch capacitor C1, the second switch capacitor C2, the third switch capacitor C3, and the fourth switch capacitor C4. The person skilled in the art can adjust the weighted addition ratio of the two audio signals by setting the capacitance values of the first switched capacitor C1, the second switched capacitor C2, the third switched capacitor C3 and the fourth switched capacitor C4.
In an alternative embodiment, a first buffer and a second buffer may also be provided in the audio amplification circuit. The positive output end of the second path of original audio signal is connected with one end of a first buffer, and the other end of the first buffer is connected with a first weighting adder; the negative output end of the second path of original audio signal is connected with one end of a second buffer, and the other end of the second buffer is connected with a second weighting adder; after the second path of original audio signal passes through the first buffer and the second buffer, the second path of original audio signal is weighted and added with the filtering signal through a weighting adder to obtain a weighted addition signal.
In this embodiment, the influence of the digital circuit on the preceding stage circuit can be avoided by adding the buffer.
In this embodiment, an original audio signal is divided into two paths, and one path of original audio signal passes through a filter to obtain a filtered signal; the other path of original audio signal is added with the filtering signal in a weighting way through a weighting adder to obtain a weighted addition signal; the weighted addition signal passes through a comparator, a digital circuit and a player in sequence to output an audio signal. Therefore, the linearity of the filtered signal can be improved by using the original audio signal of the other path, and the quality of the output audio signal is improved by performing feedforward processing on the signal entering the comparator and the digital circuit.
Example four
Fig. 4 is a schematic structural diagram of an audio amplifying circuit according to a fourth embodiment of the present invention, and as shown in fig. 4, the audio amplifying circuit in this embodiment may include: a player, a comparator, a digital circuit, a weighted adder, and a filter; after a first path of original audio signal passes through a filter, a filtering signal is obtained; weighting and adding the second path of original audio signal and the filtering signal through a weighting adder to obtain a weighted addition signal; the weighted addition signal passes through the comparator, the digital circuit and the player in sequence to output an audio signal. Wherein, the filter includes: the operational amplifier, the first capacitor and the second capacitor; the positive input end of the operational amplifier forms the positive input end of the filter, the negative input end of the operational amplifier forms the negative input end of the filter, the first output end of the operational amplifier forms the first output end of the filter, and the second output end of the operational amplifier forms the second output end of the filter; one end of the first capacitor is connected to the positive input end of the operational amplifier, and the other end of the first capacitor is connected to the first output end of the operational amplifier; one end of the second capacitor is connected to the negative input end of the operational amplifier, and the other end of the second capacitor is connected to the second output end of the operational amplifier.
Specifically, referring to fig. 4, the audio amplifying circuit in the present embodiment may include: the player comprises an integrated circuit and a player, wherein the integrated circuit consists of a first operational amplifier INT1, a second operational amplifier INT2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a comparator and a digital circuit. The positive input terminal of the first operational amplifier INT1 is connected to the positive output terminal of the first operational amplifier INT1 through a capacitor, and the negative input terminal of the first operational amplifier INT1 is connected to the negative output terminal of the first operational amplifier INT1 through a capacitor. The positive input terminal of the first operational amplifier INT1 constitutes the positive input terminal of the first-order filter, the negative input terminal of the first operational amplifier INT1 constitutes the negative input terminal of the first-order filter, the positive output terminal of the first operational amplifier INT1 constitutes the positive output terminal of the first-order filter, and the negative output terminal of the first operational amplifier INT1 constitutes the negative output terminal of the first-order filter. The positive input terminal of the second operational amplifier INT2 is connected to the positive output terminal of the second operational amplifier INT2 through a capacitor, and the negative input terminal of the second operational amplifier INT2 is connected to the negative output terminal of the second operational amplifier INT2 through a capacitor. The positive input terminal of the second operational amplifier INT2 constitutes a positive input terminal of the second-order filter, the negative input terminal of the second operational amplifier INT2 constitutes a negative input terminal of the second-order filter, the positive output terminal of the second operational amplifier INT2 constitutes a positive output terminal of the second-order filter, and the negative output terminal of the second operational amplifier INT2 constitutes a negative output terminal of the second-order filter. The first order filter and the second order filter are connected in series through a resistor. The positive signal Vip of the first audio signal is connected to the positive input end of the first-stage filter, and the negative signal Vin of the first audio signal is connected to the negative input end of the first-stage filter. Taking a two-stage filter as an example, one end of the first resistor R1 is connected to the first output terminal of the last-stage filter, and one end of the second resistor R2 is connected to the positive output terminal of the second original audio signal; the other end of the first resistor R1 and the other end of the second resistor R2 are both connected to a first input end of an integrated circuit formed by the comparator and the digital circuit; one end of the third resistor R3 is connected with the second output end of the last-stage filter, and one end of the fourth resistor R4 is connected with the negative output end of the second path of original audio signals; the other end of the third resistor R3 and the other end of the fourth resistor R4 are both connected to a second input end of the integrated circuit formed by the comparator and the digital circuit. The output end of the integrated circuit formed by the comparator and the digital circuit is connected with the player.
It should be noted that the present embodiment does not limit specific resistance values of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4. The person skilled in the art can adjust the weighted addition ratio of the two audio signals by setting the resistances of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4.
In an alternative embodiment, a first buffer and a second buffer may also be provided in the audio amplification circuit. The positive output end of the second path of original audio signal is connected with one end of a first buffer, and the other end of the first buffer is connected with a weighting adder; the negative output end of the second path of original audio signal is connected with one end of a second buffer, and the other end of the second buffer is connected with a weighting adder; after the second path of original audio signal passes through the first buffer and the second buffer, the second path of original audio signal is weighted and added with the filtering signal through a weighting adder to obtain a weighted addition signal.
In this embodiment, the influence of the digital circuit on the preceding stage circuit can be avoided by adding the buffer.
In another alternative embodiment, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 may be replaced by corresponding switched capacitors. In the audio amplifying circuit, the function of the switched capacitor is equivalent to that of the resistor.
In this embodiment, an original audio signal is divided into two paths, and one path of original audio signal passes through a filter to obtain a filtered signal; the other path of original audio signal is added with the filtering signal in a weighting way through a weighting adder to obtain a weighted addition signal; the weighted addition signal passes through a comparator, a digital circuit and a player in sequence to output an audio signal. Therefore, the linearity of the filtered signal can be improved by using the original audio signal of the other path, and the quality of the output audio signal is improved by performing feedforward processing on the signal entering the comparator and the digital circuit.
EXAMPLE five
Fig. 5 is a schematic structural diagram of an audio amplifying circuit according to a fifth embodiment of the present invention, and as shown in fig. 5, the audio amplifying circuit in this embodiment may include: the player comprises an integrated circuit consisting of a first operational amplifier INT1, a second operational amplifier INT2, a weighting adder, a comparator and a digital circuit. The positive input terminal of the first operational amplifier INT1 is connected to the positive output terminal of the first operational amplifier INT1 through a capacitor, and the negative input terminal of the first operational amplifier INT1 is connected to the negative output terminal of the first operational amplifier INT1 through a capacitor. The positive input terminal of the first operational amplifier INT1 constitutes the positive input terminal of the first-order filter, the negative input terminal of the first operational amplifier INT1 constitutes the negative input terminal of the first-order filter, the positive output terminal of the first operational amplifier INT1 constitutes the positive output terminal of the first-order filter, and the negative output terminal of the first operational amplifier INT1 constitutes the negative output terminal of the first-order filter. The positive input terminal of the second operational amplifier INT2 is connected to the positive output terminal of the second operational amplifier INT2 through a capacitor, and the negative input terminal of the second operational amplifier INT2 is connected to the negative output terminal of the second operational amplifier INT2 through a capacitor. The positive input terminal of the second operational amplifier INT2 constitutes a positive input terminal of the second-order filter, the negative input terminal of the second operational amplifier INT2 constitutes a negative input terminal of the second-order filter, the positive output terminal of the second operational amplifier INT2 constitutes a positive output terminal of the second-order filter, and the negative output terminal of the second operational amplifier INT2 constitutes a negative output terminal of the second-order filter. The first-order filter and the second-order filter are connected through a parallel connection result formed by a resistor and a capacitor. The positive signal Vip of the first audio signal is connected to the positive input end of the first-stage filter, and the negative signal Vin of the first audio signal is connected to the negative input end of the first-stage filter. Taking a two-order filter as an example, the first-order filter and the second-order filter are connected in series, wherein a positive output end of the first-order filter is connected to a positive input end of the second-order filter, and a positive output end of the second-order filter is connected to a positive input end of the second-order filter. The positive output terminal of the last order filter is connected to the first input port of the first weighted adder, and the negative output terminal of the last order filter is connected to the first input port of the second weighted adder. The output ends of the two weighted adders are connected to the input end of an integrated circuit formed by the comparator and the digital circuit, and the output end of the integrated circuit formed by the comparator and the digital circuit is connected with the player.
In an alternative embodiment, when the number of the filters is N, and N is a natural number greater than 1, the filters are sequentially connected in series to form an N-th order filter. Wherein, the firstiThe order filter includes: a third capacitor, a fifth resistor, a fourth capacitor and a sixth resistor; one end of the third capacitor is connected to the firsti-1 order filteringThe positive input end of the device, the other end of the third capacitor is connected with one end of a fifth resistor, and the other end of the fifth resistor is connected with the second resistori-a second output of the order 1 filter; one end of the fourth capacitor is connected to the firsti-a negative input of the filter of order 1, the other terminal of the fourth capacitor being connected to one terminal of a sixth resistor, the other terminal of the sixth resistor being connected to the second terminali-a first output of a filter of order 1; wherein the content of the first and second substances,ithe value range of (a) is 2, 3, …, N.
In another alternative embodiment, the first stepiThe order filter includes: a third capacitor, a fifth switched capacitor, a fourth capacitor and a sixth switched capacitor; one end of the third capacitor is connected to the firsti-a positive input of an order 1 filter, the other terminal of the third capacitor being connected to one terminal of a fifth switched capacitor, the other terminal of the fifth switched capacitor being connected to the fourth switchi-a second output of the order 1 filter; one end of the fourth capacitor is connected to the firsti-a negative input of the order 1 filter, the other terminal of the fourth capacitor being connected to one terminal of a sixth switched capacitor, the other terminal of the sixth switched capacitor being connected to the second terminal of the fourth switched capacitori-a first output of a filter of order 1; wherein the content of the first and second substances,ithe value range of (a) is 2, 3, …, N.
The third capacitor, the fourth capacitor, andithe capacitance values of the first capacitor and the second capacitor of the 1 st order filter are the same.
In the embodiment, a filtered signal is obtained by passing an original audio signal through an N-order filter; the filtered signal passes through a comparator and a digital circuit and then outputs a corresponding digital signal; the number of the operational amplifiers adopted in the N-order filter is smaller than N, and N is a natural number larger than 1. The utility model discloses an amplifying circuit, under the prerequisite of guaranteeing the filtering effect, the quantity through the operational amplifier who uses in reducing the N rank filter reduces the shared circuit area of amplifying circuit and consumption.
Additionally, the utility model also provides a playback device, be provided with in this playback device as shown in any one of fig. 1~ 5 amplifier circuit.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless specifically stated otherwise.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (10)
1. An audio amplification circuit, comprising: a player, a comparator, a digital circuit, a weighted adder, and a filter; after the first path of original audio signal passes through the filter, a filtering signal is obtained; the second path of original audio signal is added with the filtering signal in a weighting way through the weighting adder to obtain a weighted addition signal; the weighted addition signal passes through the comparator, the digital circuit and the player in sequence to output an audio signal.
2. The circuit of claim 1, wherein the weighted adder comprises: the circuit comprises a first resistor, a second resistor, a third resistor and a fourth resistor;
one end of the first resistor is connected with the first output end of the last-order filter, and one end of the second resistor is connected with the positive output end of the second path of original audio signals; the other end of the first resistor and the other end of the second resistor are both connected to a first input end of an integrated circuit formed by the comparator and the digital circuit;
one end of the third resistor is connected with the second output end of the last-order filter, and one end of the fourth resistor is connected with the negative output end of the second path of original audio signals; the other end of the third resistor and the other end of the fourth resistor are both connected to a second input end of an integrated circuit formed by the comparator and the digital circuit.
3. The circuit of claim 1, wherein the weighted adder comprises: the first switch capacitor, the second switch capacitor, the third switch capacitor and the fourth switch capacitor;
one end of the first switch capacitor is connected with the first output end of the last-order filter, and one end of the second switch capacitor is connected with the positive output end of the second path of original audio signal; the other end of the first switch capacitor and the other end of the second switch capacitor are both connected to a first input end of an integrated circuit formed by the comparator and the digital circuit;
one end of the third switched capacitor is connected with the second output end of the last-stage filter, and one end of the fourth switched capacitor is connected with the negative output end of the second path of original audio signal; the other end of the third switch capacitor and the other end of the fourth switch capacitor are both connected to a second input end of an integrated circuit formed by the comparator and the digital circuit.
4. The circuit of any of claims 1-3, further comprising: a first buffer and a second buffer;
the positive output end of the second path of original audio signal is connected with one end of the first buffer, and the other end of the first buffer is connected with the weighting adder; the negative output end of the second path of original audio signal is connected with one end of the second buffer, and the other end of the second buffer is connected with the weighting adder; after the second path of original audio signal passes through the first buffer and the second buffer, the second path of original audio signal is weighted and added with the filtering signal through the weighting adder to obtain a weighted and added signal.
5. The circuit according to any one of claims 1-3, wherein when the number of the filters is N, and N is a natural number greater than 1, the filters are connected in series in sequence to form an N-order filter.
6. The circuit of claim 5, wherein the filter comprises: the operational amplifier, the first capacitor and the second capacitor;
the positive input end of the operational amplifier forms the positive input end of the filter, the negative input end of the operational amplifier forms the negative input end of the filter, the first output end of the operational amplifier forms the first output end of the filter, and the second output end of the operational amplifier forms the second output end of the filter; one end of the first capacitor is connected to the positive input end of the operational amplifier, and the other end of the first capacitor is connected to the first output end of the operational amplifier; one end of the second capacitor is connected to the negative input end of the operational amplifier, and the other end of the second capacitor is connected to the second output end of the operational amplifier.
7. The circuit of claim 6, wherein the first stepiThe order filter includes: a third capacitor, a fifth resistor, a fourth capacitor and a sixth resistor;
one end of the third capacitor is connected to the firsti-a positive input terminal of an order-1 filter, the other terminal of the third capacitor being connected to one terminal of the fifth resistor, the other terminal of the fifth resistor being connected to the second terminal of the third resistori-a second output of the order 1 filter;
one end of the fourth capacitor is connected to the firsti-a negative input terminal of a filter of order 1, the other terminal of said fourth capacitor being connected to one terminal of said sixth resistor, the other terminal of said sixth resistor being connected to said second terminali-a first output of a filter of order 1; wherein the content of the first and second substances,ithe value range of (a) is 2, 3, …, N.
8. The circuit of claim 6, wherein the first stepiThe order filter includes: a third capacitor, a fifth switched capacitor, a fourth capacitor and a sixth switched capacitor;
one end of the third capacitor is connected to the firsti-a positive input terminal of an order-1 filter, the other terminal of the third capacitor being connected to one terminal of the fifth switched capacitor, the other terminal of the fifth switched capacitor being connected to the third switchi-a second output of the order 1 filter;
one end of the fourth capacitor is connected to the firsti-a negative input of a filter of order 1, the other terminal of said fourth capacitor being connected to one terminal of said sixth switched capacitor, the other terminal of said sixth switched capacitor being connected to said second switchi-a first output of a filter of order 1; wherein the content of the first and second substances,ithe value range of (a) is 2, 3, …, N.
9. The circuit of claim 7 or 8, wherein the third capacitance, the fourth capacitance, and theiThe capacitance values of the first capacitor and the second capacitor of the 1 st order filter are the same.
10. A playback device, characterized in that it comprises an audio amplification circuit as claimed in any one of claims 1-9.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201922357764.7U CN210274516U (en) | 2019-12-25 | 2019-12-25 | Audio amplifying circuit and playback apparatus |
| PCT/CN2020/116571 WO2021128991A1 (en) | 2019-12-25 | 2020-09-21 | Audio amplification circuit and playback device |
| US17/849,599 US20220329218A1 (en) | 2019-12-25 | 2022-06-25 | Audio amplifying circuit and playing device |
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| CN201922357764.7U CN210274516U (en) | 2019-12-25 | 2019-12-25 | Audio amplifying circuit and playback apparatus |
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| WO2021128991A1 (en) * | 2019-12-25 | 2021-07-01 | 锐迪科微电子（上海）有限公司 | Audio amplification circuit and playback device |
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| US20110255698A1 (en) * | 2010-04-19 | 2011-10-20 | Hubert Young | Programmable noise gate for audio amplifier employing a combination of low-noise and noise-rejecting analog and digital signal processing |
| CN102378085B (en) * | 2010-08-21 | 2014-12-17 | 比亚迪股份有限公司 | Equal-loudness contour-based loudness compensation method and device, and audio processing system |
| CN103634726B (en) * | 2013-08-30 | 2017-03-08 | 苏州上声电子有限公司 | A kind of Automatic loudspeaker equalization method |
| CN108347670B (en) * | 2017-01-23 | 2020-03-20 | 芯籁半导体股份有限公司 | Signal processing method and signal processing system |
| CN210274516U (en) * | 2019-12-25 | 2020-04-07 | 锐迪科微电子（上海）有限公司 | Audio amplifying circuit and playback apparatus |
| CN210518805U (en) * | 2019-12-25 | 2020-05-12 | 锐迪科微电子（上海）有限公司 | Amplifying circuit and playing device |
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