CN207124734U - Audio output balancing circuitry and earphone - Google Patents

Abstract

The utility model discloses a kind of audio output balancing circuitry and earphone.The circuit includes impedance detection circuit, audio drive circuitry, resistance adjustment circuit, at least two audio output units；The resistance adjustment circuit connected in series is between the audio output and at least two audio output units of audio drive circuitry；It is connected to detect the test side of the impedance detection circuit of the resistance between the audio drive circuitry audio output and at least two audio output units respectively with the audio output of the audio drive circuitry and at least two audio output unit；Testing result for the test side according to the impedance detection circuit controls the control output end of the impedance detection circuit of the resistance output of the resistance adjustment circuit to be connected with the resistance adjustment circuit.The embodiment of the circuit can be adjusted the resistance of circuit between audio output and each audio output unit to identical.

Description

Audio output balancing circuitry and earphone

Technical field

Audio frequency process is the utility model is related to, more particularly, to a kind of audio output balancing circuitry and earphone.

Background technology

In existing a kind of earphone, its earphone control circuit can be placed on earphone side, earphone control circuit to left and right loudspeaker Distance it is different, cause the conductor length of audio output to the left and right loudspeaker of earphone control circuit inconsistent.Because wire has There is resistance, it is inconsistent in turn result in the impedance of audio output to the left and right loudspeaker of earphone control circuit, causes left and right loudspeaker The uniformity for exporting audio is poor.

Utility model content

A purpose of the present utility model is to provide a kind of new solution of audio output balancing circuitry, so that audio is defeated Go out that the resistance of circuit between end and each audio output unit is identical, strengthen the consistent of audio output between different audio output units Property.

According to first aspect of the present utility model, there is provided a kind of audio output balancing circuitry, including impedance detection circuit, sound Frequency drive circuit, resistance adjustment circuit, at least two audio output units；Wherein, the resistance adjustment circuit connected in series is described Between the audio output of audio drive circuitry and at least two audio output unit；Driven to detect the audio respectively The test side of the impedance detection circuit of dynamic resistance between circuit audio output end and at least two audio output units and institute State audio output and at least two audio output unit connection of audio drive circuitry；For according to the impedance detection The testing result of the test side of circuit controls the control of the impedance detection circuit of the resistance output of the resistance adjustment circuit Output end is connected with the resistance adjustment circuit.

Alternatively, the resistance adjustment circuit includes：At least two resistance adjustment circuits；And at least two resistance is adjusted Economize on electricity road and the one-to-one connection of at least two audio output units；The control output end of the impedance detection circuit with it is described The connection of resistance adjustment circuit includes：The control output end of the impedance detection circuit connects with least two resistance adjustments circuit Connect.

Alternatively, at least two audio output unit includes：First audio output unit and the second audio output list Member；At least two resistance adjustments circuit includes：First resistor adjusts circuit and second resistance regulation circuit；Described at least two Individual resistance adjustment circuit includes with the one-to-one connection of at least two audio output unit：The first resistor adjusts circuit string It is associated between the audio output of audio drive circuitry and first audio output unit；The second resistance adjusts circuit string It is associated between the audio output of audio drive circuitry and second audio output unit.

Alternatively, the output end of the audio drive circuitry includes：First audio output and the second audio output；The One resistance adjustment circuit connected in series includes between the audio output and first audio output unit of audio drive circuitry：Institute State first resistor regulation circuit connected in series audio drive circuitry the first audio output and first audio output unit it Between；Second resistance regulation circuit connected in series audio drive circuitry audio output and second audio output unit it Between include：Second resistance adjusts second audio output and the second audio output list of the circuit connected in series in audio drive circuitry Between member.

Alternatively, the test side of the impedance detection circuit includes：First test side and the second test side；The impedance inspection The test side of slowdown monitoring circuit and the audio output and first audio output unit and the second audio of the audio drive circuitry Output unit connection includes：First test side of the impedance detection circuit and the audio output of the audio drive circuitry and The first audio output unit connection, the second test side of the impedance detection circuit and the audio of the audio drive circuitry Output end and second audio output unit connection.

Alternatively, the resistance adjustment circuit includes digital regulation resistance.

Alternatively, the impedance detection circuit includes：Controlled switch, resistance measuring circuit, control circuit, it is described controlled to open The audio output of the first end connection audio drive circuitry of pass, the second end connect the resistance measuring circuit, control terminal connection The control circuit；The resistance adjustment circuit and the resistance measuring circuit are connected with the control circuit；The control electricity Road is configured in when need to detect the resistance between the audio drive circuitry audio output and at least two audio output units, control Make the circuit between the audio output of the controlled switch conducting audio drive circuitry and the resistance measuring circuit, and root The resistance that the resistance adjustment circuit is adjusted according to the measurement result of resistance measuring circuit feedback exports.

According to second aspect of the present utility model, there is provided a kind of earphone, including preceding described circuit.

Alternatively, in addition to earphone control chip, the impedance detection circuit are integrated in earphone control chip.

Alternatively, the resistance adjustment circuit includes digital regulation resistance, and the digital regulation resistance includes MAX5434 chips.

By resistance adjustment circuit connected in series between audio output circuit audio output and each audio output unit.Pass through Resistance between the audio output and each audio output unit of impedance detection circuit detection audio drive circuitry, and control accordingly The resistance output of resistance adjustment circuit.So that between the audio output of audio drive circuitry and each audio output unit Resistance is identical, improves the uniformity of audio output between each audio output unit.

It is of the present utility model other by referring to the drawings to the detailed description of exemplary embodiment of the present utility model Feature and its advantage will be made apparent from.

Brief description of the drawings

It is combined in the description and the accompanying drawing of a part for constitution instruction shows embodiment of the present utility model, and And it is used to explain principle of the present utility model together with its explanation.

Fig. 1 is the block diagram for the audio output balancing circuitry that embodiment of the present utility model provides.

Fig. 2 is the block diagram for the audio output balancing circuitry that another embodiment of the present utility model provides.

Fig. 3 is the block diagram for the impedance detection circuit that embodiment of the present utility model provides.

Fig. 4 (a) is that controlled switch 4s and resistance measuring circuit 4t corresponds to the first audio output P1a parts in Fig. 3 Circuit diagram.

Fig. 4 (b) is that controlled switch 4s and resistance measuring circuit 4t corresponds to the second audio output P1b parts in Fig. 3 Circuit diagram.

Fig. 5 is the schematic diagram for the audio output balancing circuitry that another embodiment of the present utility model provides.

Embodiment

Various exemplary embodiments of the present utility model are described in detail now with reference to accompanying drawing.It should be noted that：It is unless another Illustrate outside, the part and the positioned opposite of step, numerical expression and numerical value otherwise illustrated in these embodiments is unlimited The scope of the utility model processed.

The description only actually at least one exemplary embodiment is illustrative to be never used as to this practicality below New and its application or any restrictions used.

It may be not discussed in detail for technology, method and apparatus known to person of ordinary skill in the relevant, but suitable In the case of, the technology, method and apparatus should be considered as part for specification.

In shown here and discussion all examples, any occurrence should be construed as merely exemplary, without It is as limitation.Therefore, other examples of exemplary embodiment can have different values.

It should be noted that：Similar label and letter represents similar terms in following accompanying drawing, therefore, once a certain Xiang Yi It is defined, then it need not be further discussed in subsequent accompanying drawing in individual accompanying drawing.

The utility model embodiment provides a kind of audio output balancing circuitry, and the circuit includes audio drive circuitry 1, electricity Resistance regulation circuit 3, the audio output unit of impedance detection circuit 4 and at least two.Resistance adjustment circuit 3 is connected on audio driven electricity Between the audio output on road 1 and at least two audio output units.The test side of impedance detection circuit 4 and audio drive circuitry 1 audio output and the connection of at least two audio output units；The control output end of impedance detection circuit 4 and resistance adjustment electricity Road 3 connects.

So, the audio output of audio drive circuitry 1 and at least two are detected in the test side of impedance detection circuit 4 respectively Resistance between individual audio output unit, the control output end of impedance detection circuit 4 control resistance adjustment circuit 3 according to testing result Resistance output, to cause the resistance of circuit between the audio output of audio drive circuitry 1 and each audio output unit identical.From And improve the uniformity of audio output between each audio output unit.

Further, above-mentioned at least two output unit includes the first audio output unit 21, the second audio output unit 22.First audio output unit 21 and the second audio output unit 22 for example can be two loudspeakers or two sounds of earphone Case loudspeaker etc..

The block diagram of audio output balancing circuitry shown in Figure 1.The circuit includes audio drive circuitry 1, resistance adjustment Circuit 3, impedance detection circuit 4, the first audio output unit 21 and the second audio output unit 22.

Now, the audio output P11 of audio drive circuitry 1 is defeated with the first audio output unit 21 and the second audio respectively Go out unit 22 to connect, for driving the first audio output unit 21 and the exports audio signal of the second audio output unit 22.

First audio output unit 21 and the second audio output unit 22 can share an identical audio output P11.And in other example, audio output P11 includes the first audio output and the second audio output (in Fig. 1 It is not shown).First audio output is connected and drives the first audio output unit 21, and the second audio output is connected and driven Second audio output unit 22.In actual circuit, each audio output includes positive and negative both ends, each audio output list The positive and negative both ends of first audio output corresponding to connection respectively.

Resistance adjustment circuit 3 be connected on audio drive circuitry 1 audio output P11 and the first audio output unit 21 and Between second audio output unit 22.

Resistance adjustment circuit 3 be, for example, digital regulation resistance or other can receive control adjust its resistance output devices or Circuit.

Impedance detection circuit 4 detects the audio output P11 and the first audio output unit 21 of audio drive circuitry 1 respectively And the resistance between the second audio output unit 22.Impedance detection circuit 4 controls the electricity of resistance adjustment circuit 3 according to the resistance Resistance output, to cause the audio output P11 of audio drive circuitry 1 and the first audio output unit 21 and audio output P11 It is identical with the resistance of second 22 circuits of audio output unit.The resistance is identical be not limited to it is definitely equal, it is allowed to one can be with The error range of receiving.

The circuit being arranged such, it is possible to achieve between the audio output of audio drive circuitry and each audio output unit Impedance matching.

Further, resistance adjustment circuit 3 includes：At least two resistance adjustment circuits, and at least two resistance adjustments electricity Road and the one-to-one connection of at least two audio output units.Now, the control output end of impedance detection circuit 4 and resistance adjustment electricity The connection of road 3 includes：The control output end of impedance detection circuit 4 is connected with least two resistance adjustment circuits.So, hindering Anti- detection circuit 4 is for circuit between the audio output unit 2 where each audio output unit and audio drive circuitry 1, detection After going out the resistance of circuit, each audio output unit 2 and the resistance adjustment electricity connected between audio drive circuitry 1 can be adjusted respectively Road, and then make the audio output of audio drive circuitry 1 identical with the resistance of each 2 circuits of audio output unit.

Further, when audio output unit 2 includes the first audio output unit 21 and the second audio output unit 22, Resistance adjustment circuit 3 includes first resistor regulation circuit 3a and second resistance regulation circuit 3b.First resistor regulation circuit 3a strings It is associated between the audio output P11 of audio drive circuitry 1 and the first audio output unit 21；Second resistance regulation circuit 3b strings It is associated between the audio output P11 of audio drive circuitry 1 and the second audio output unit 22.

Further, in order to adapt to the demand that user is apparent to audio signal, three-dimensional, each audio output unit it is defeated Go out audio to have differences, therefore audio drive circuitry can be directed to each audio output unit and export different audio signals.This When, the output end P11 of audio drive circuitry 1 is at least two, and is connected one to one with least two audio output units.

Further, when audio output unit 2 includes the first audio output unit 21 and the second audio output unit 22, The output end P11 of audio drive circuitry 1 includes：First audio output P1a and the second audio output P1b.

Now, first resistor regulation circuit 3a be connected on audio drive circuitry 1 audio output P11 and the first audio it is defeated Going out between unit 21 includes：

First resistor regulation circuit 3a be connected on audio drive circuitry 1 the first audio output P1a and the first audio it is defeated Go out between unit 21.

Second resistance regulation circuit 3b is connected on the audio output P11 and the second audio output list of audio drive circuitry 1 Include between member 22：

Second resistance regulation circuit 3b is connected on the second audio output P1b and the second audio output of audio drive circuitry Between unit 22.

Further, in order to more accurately measure each audio output of audio drive circuitry 1 and audio output list The resistance of first 2 circuits, can be by the test side of impedance detection circuit 4 for each audio output and audio output unit 2 Between circuit set one, the circuit between each audio output and audio output unit 2 of audio drive circuitry 1 is entered respectively Row detection.

Further, when audio output unit 2 includes the first audio output unit 21 and the second audio output unit 22, The test side of impedance detection circuit 4 includes：First test side P41a and the second test side P41b.

Now, the test side of impedance detection circuit 4 and the audio output P11 of audio drive circuitry 1 and the first audio are defeated Going out the connection of the audio output unit 22 of unit 21 and second includes：

First test side P41a of impedance detection circuit 4 and the audio output P11 and the first audio of audio drive circuitry 1 Output unit 21 connects, the second test side P41b of impedance detection circuit 4 and the audio output P11 of audio drive circuitry 1 and Second audio output unit 22 connects.

So, the first audio output unit 21 and the second audio output unit 22 are included in audio output balancing circuitry When, impedance detection circuit 4 detects the audio output P11 and the first audio of audio drive circuitry 1 by the first test side P41a The impedance of 21 circuits of output unit.The audio output P11 and the of audio drive circuitry 1 is detected by the second test side P41b The impedance of two 22 circuits of audio output unit, and according to the detection knot of the first test side P41a and the second test side P41b respectively Fruit regulation first resistor regulation circuit 3a and the resistance of second resistance regulation circuit 3b outputs, so that audio drive circuitry 1 The impedance of circuit between audio output P11 and the first audio output unit 21, and the audio output P11 of audio drive circuitry 1 It is identical with the impedance of second 22 circuits of audio output unit.

The block diagram of audio output balancing circuitry as shown in Figure 2 is an example of circuit shown in Fig. 1.The circuit includes sound Frequency drive circuit 1, the first audio output unit 21, the second audio output unit 22, first resistor regulation circuit 3a, second resistance Adjust circuit 3b, impedance detection circuit 4.

Now, audio drive circuitry 1 includes the first audio output P1a, the second audio output P1b.Impedance detection electricity Road 4 includes the first test side P41a, the second test side P41b, the first control output end P42a, the second control output end P42b.

First audio output P1a of audio drive circuitry 1 adjusts circuit 3a and the first audio output by first resistor Unit 21 connects, to drive the first audio output unit 21 to send sound.

Second audio output P1b of audio drive circuitry 1 adjusts circuit 3b and the second audio output by second resistance Unit 22 connects, to drive the second audio output unit 22 to send sound.

In other example, first resistor regulation circuit 3a and second resistance regulation circuit 3b can be only existed wherein One resistance adjustment circuit.As, adjusted by resistance adjustment circuit the audio output of audio drive circuitry 1 with it is each Resistance between audio output unit.

In other example, the audio output of audio drive circuitry 1 is a public audio output, the sound Frequency output end drives the first audio output unit 21 and the second audio output unit 22 simultaneously.

First test side P41a connections the first audio output P1a of impedance detection circuit 4 and the first audio output unit 21, to detect the resistance of circuit between the first audio output P1a and the first audio output unit 21.

Second test side P41b connections the second audio output P1b of impedance detection circuit 4 and the second audio output unit 22, to detect the resistance of circuit between the second audio output P1b and the second audio output unit 22.

In other example, impedance detection circuit 4 only has a test side, the test side and the first audio output P1a, the second audio output P1b, the first audio output unit 21, the second audio output unit 22 connect.

Further, the resistance of circuit includes audio between the audio output and audio output unit of audio drive circuitry The resistance of circuit and the internal resistance of audio output unit between the audio output and audio output unit of drive circuit.As, The resistance of circuit includes the first audio output P1a and the between first audio output P1a and the first audio output unit 21 The internal resistance of the resistance of circuit and the first audio output unit 21 between one audio output unit 21.Second audio output P1b with The resistance of circuit is included between the second audio output P1b and the second audio output unit 22 between second audio output unit 22 The internal resistance of the resistance of circuit and the second audio output unit 22.

Now, impedance detection circuit can not only detect the audio output and audio output unit of audio drive circuitry Between circuit resistance, can also detect that the internal resistance of each audio output unit.So, by adjusting each resistance Circuit is adjusted, can make it that the audio output of audio drive circuitry is identical with the resistance between each audio output unit.

It should be noted that in the circuit of reality, each test side of impedance detection circuit 4 can be respectively connecting to sound The positive and negative both ends of the corresponding audio output of frequency drive circuit 1, to measure the positive and negative both ends and corresponding audio output unit Between resistance.

Further, impedance detection circuit 4 controls first resistor regulation circuit 3a and second resistance regulation circuit 3b respectively Resistance output.Now impedance detection circuit 4 can export different signals by a control output end, can also pass through To export corresponding signal respectively, to control, first resistor adjusts circuit 3a and second resistance adjusts circuit for two control output ends 3b。

When impedance detection circuit 4 includes two control output ends, the first control output end P42a of impedance detection circuit 4 First resistor regulation circuit 3a is connected, to control first resistor regulation circuit 3a resistance output.

The second control output end P42b connections second resistance regulation circuit 3b of impedance detection circuit 4, to control second Resistance adjustment circuit 3b resistance output.

The resistance value control that impedance detection circuit 4 acquires according to detection, which is adjusted, increases or adjusts and reduce wherein some resistance adjustment circuit Resistance output so that resistance between the first audio output P1a and the first audio output unit 21 and the second audio output Hold P1b equal with the resistance between the second audio output unit 22.It should be noted that in the utility model embodiment, resistance Be worth it is equal be not limited to definitely it is equal, allow for certain error range.

Fig. 3 shows the internal frame diagram of foregoing impedance detection circuit 4.

The impedance detection circuit 4 includes controlled switch 4s, resistance measuring circuit 4t, control circuit 4c.

The audio output of the foregoing audio drive circuitry 1 of controlled switch 4s first end P4s1 connections, the second end P4s2 Connect resistance measuring circuit 4t, control terminal P4c connection control circuits 4c.

Control circuit 4c is connected with resistance measuring circuit 4t, to obtain resistance measuring circuit 4t resistivity measurements.

Control circuit 4c is also connected with foregoing resistance adjustment circuit 3, to the resistance output of control circuit regulation circuit 3.

When the corresponding audio output unit of some audio output that need not measure aforementioned audio drive circuit 1 it Between resistance when, control circuit 4c control disconnect corresponding to controlled switch 4s first end P4s1 and the second end P4s2 between company Connect；Otherwise the first end P4s1 and the second end P4s2 of controlled switch 4s corresponding to control circuit 4c controls connection.

The resistance that control circuit 4c adjusts circuit 3 according to resistance measuring circuit 4t measurement result regulation resistance exports.

Alternatively, control circuit 4c is also connected with aforementioned audio drive circuit 1 and (is not shown in Fig. 3), when measure some During resistance between audio output and corresponding audio output unit, control circuit 4c sends control letter to audio drive circuitry 1 Number, after receiving the control signal so as to audio drive circuitry 1, control corresponding audio output output high-impedance state or control the audio Output end disconnects the connection with the internal circuit of audio drive circuitry 1, and so, resistance measuring circuit 4t only measures audio output The internal resistance of line resistance and audio output unit 2 between end and audio output unit 2.

Fig. 4 (a) is that controlled switch 4s and resistance measuring circuit 4t corresponds to the first audio output P1a parts in Fig. 3 Circuit diagram, Fig. 4 (b) are the electricity that controlled switch 4s and resistance measuring circuit 4t corresponds to the second audio output P1b parts in Fig. 3 Lu Tu.Circuit shown in Fig. 4 (a) and Fig. 4 (b) together constitutes one of controlled switch 4s and resistance measuring circuit 4t in Fig. 3 The circuit diagram of example.

In this circuit arrangement, the first audio output P1a is the first positive negative audio outputs of audio output LP and first LN.First audio output unit 21 is left horn 6.Now, the first positive negative audio output LN of audio output LP and first lead to Tone frequency channel wire is crossed to connect and drive left horn 6.

Second audio output P1b is the second positive negative audio output RN of audio output RP and second.Second audio Output unit 22 is right horn 7.Now, the second positive negative audio output RN of audio output RP and second are connected by tone frequency channel wire And drive right horn 7.

Resistance measuring circuit 4t includes first resistor measuring circuit U1 and second resistance measuring circuit U2.Wherein, the first electricity Hinder the resistance value that measuring circuit U1 is used to measure circuit between first positive and negative audio output LP, LN and the first left horn 6.Second Resistance measuring circuit U2 is used for the resistance value of circuit between second positive and negative audio output RP, RN and right horn 7 of measurement.

In this circuit arrangement, controlled switch 4s be switch SW1- switch SW8, its by aforementioned control circuit 4c control, only when When needing to measure audio output with the resistance value between corresponding loudspeaker, corresponding switch is controlled to be in connected state.Shown in Fig. 4 Whole controlled switch SW1-SW8 be in connected state.

Specifically, when switch SW1 is in connected state, the first negative audio output LN ground connection；Connect when switch SW2 is in During logical state, the first positive audio output LP meets power supply VCC by first resistor R1；The positive and negative audio output of such R1 and first The equivalent resistance of circuit forms resistor voltage divider circuit between end.Switch two of SW3, SW4 control first resistor measuring circuit U1 The connection of input and first positive and negative audio output LP, LN.

When switch SW5 is in connected state, the second negative audio output RN ground connection；When switch SW6 is in connected state When, the second positive audio output RP passes through the 5th resistance R5 connection power supplys VCC；Such positive and negative audio outputs of R5 and second it Between circuit equivalent resistance form resistor voltage divider circuit.Switch SW7, SW8 control second resistance measuring circuit U2 two are defeated Enter end and second positive and negative audio output RP, RN connection.

Illustrate resistance measurement electricity exemplified by resistance value for first positive and negative audio output LP, LN and left horn 6 of measurement Road U1 operation principle.Resistance measuring circuit U2 operation principle is same.

The equivalent resistance that first resistor R1 is formed with first positive and negative audio output LP, LN and left horn 6 circuit is connected Between power supply VCC and ground.

First resistor measuring circuit U1 is included by second resistance R2,3rd resistor R3, the 4th resistance R4, the first operation amplifier The ratio circuit of device U3 compositions and the voltage analog to digital conversion circuit ADC1 for connecting the ratio circuit.

Wherein, one end connecting valve SW3 of second resistance one end, the other end connect the in the same direction of the first operational amplifier U3 Input；One end connecting valve SW4 of 3rd resistor one end, the other end connect the first operational amplifier U3 reverse input End.4th resistance R4 one end connects the first operational amplifier U3 reverse input end, and the other end connects the first operational amplifier U3 output end.First operational amplifier U3 output end connection voltage analog to digital conversion circuit ADC1 input.

It should be noted that ratio circuit is used to amplify measurement voltage ratio, voltage analog to digital conversion circuit is used to measure Magnitude of voltage is general knowledge known in this field, and it is not described here in detail.

Voltage analog to digital conversion circuit ADC1 by the voltage conversion that the first operational amplifier U3 is exported into data signal export to Control circuit 4c (is not shown) in Fig. 4.By the magnitude of voltage divided by the 4th resistance R4 and 3rd resistor R3 ratio, that is, obtain the The magnitude of voltage at one positive and negative audio output LP, LN both ends.

Because voltage VCC is known and first resistor resistance R1, first positive and negative audio output LP, LN and left loudspeaker 6 magnitude of voltage at equivalent resistance both ends that is formed of circuit has also obtained through preceding method, can be counted by electric resistance partial pressure formula Calculate the resistance value of the equivalent resistance of first positive and negative audio output LP, LN and left horn 6 circuit formation.

In the various embodiments described above, audio drive circuitry 1 and impedance detection circuit 4, independent circuit or chip are may each be, Earphone control chip can also be integrated in.Earphone control chip is, for example, Bluetooth chip CSR8670C, and it has been internally integrated audio Drive circuit 1 and impedance detection circuit 4.

Resistance adjustment circuit in the various embodiments described above, such as can be made up of MAX5434 chips.MAX5434 chips External signal can be received and control the resistance adjusted between two resistance output end.

Audio output balancing circuitry shown in Figure 5, circuit chips CSR8670C are internally integrated foregoing sound Frequency drive circuit and foregoing impedance detection circuit.

Chip CSR8670C first positive and negative audio output LP, LN is connected and is driven left horn 6, chip CSR8670C Second positive and negative audio output RP, RN connect and drive right horn 7.

A MAX5434 core is in series with tone frequency channel wire between first positive and negative audio output LP, LN and left horn 6 Piece.Second positive and negative audio output RP, RN and right horn 7 between tone frequency channel wire on be in series with a MAX5434 chip.

The resistance value of two MAX5434 chip reality outputs is by CSR8670C chip controls.Specifically, CSR8640C chips The first serial clock output end SCL1 and the first serial data output terminal SDA1 be used for being connected on the first positive and negative audio output Hold the MAX5434 chips output control on the tone frequency channel wire between LP, LN and left horn 6 to instruct, control its L port and W ports it Between resistance output.The the second serial clock output end SCL2 and the second serial data output terminal SDA2 of CSR8640C chips are used for MAX5434 chip output controls on the tone frequency channel wire being connected between second positive and negative audio output RP, RN and right horn 7 Instruction, controls the resistance between its L port and W ports to export.

The pin T1 of CSR8640C chips is connected to the first positive audio output LP, and it is defeated that pin T2 is connected to the first negative audio Go out to hold LN.The pin T3 of CSR8640C chips is connected to the second positive audio output RP, and it is defeated that pin T4 is connected to the second negative audio Go out to hold RN.

When the resistance of circuit between needing first positive and negative audio output LP, LN and left horn 6 of measurement, CSR8640C cores Audio drive circuitry inside piece control exports high-impedance state, and CSR8640C chips in first positive and negative audio output LP, LN Controlling switch T1 and pin T2 connect with the resistance measuring circuit of CSR8640C chip internals, and resistance measuring circuit detects first The resistance of circuit between positive and negative audio output LP, LN and left horn 6.Wherein, when resistance measurement need not be carried out, CSR8640C chip controls pin T1 and pin T2 and CSR8640C chip internals resistance measuring circuit disconnect.

When the resistance of circuit between needing second positive and negative audio output RP, RN and right horn 7 of measurement, CSR8640C cores Audio drive circuitry inside piece control exports high-impedance state, and CSR8640C chips in second positive and negative audio output RP, RN Controlling switch T3 and pin T4 connect with the resistance measuring circuit of CSR8640C chip internals, and resistance measuring circuit detects second The resistance of circuit between positive and negative audio output RP, RN and right horn 7.Wherein, when resistance measurement need not be carried out, CSR8640C chip controls pin T3 and pin T4 and CSR8640C chip internals resistance measuring circuit disconnect.

The control circuit of CSR8640C chip internals is according to detect first positive and negative audio output LP, LN and left loudspeaker The resistance value of circuit between the resistance value of 6 circuits and second positive and negative audio output RP, RN and right horn 7, adjusts two The resistance of MAX5434 chips or one of MAX5434 chips exports, to cause foregoing first positive and negative audio output LP, LN With the resistance value of 6 circuits of left horn, and second positive and negative audio output RP, RN and circuit between right horn 7 resistance value phase Together.

Although some specific embodiments of the present utility model are described in detail by example, this area It is to be understood by the skilled artisans that example above merely to illustrate, rather than in order to limit the scope of the utility model.This Field it is to be understood by the skilled artisans that can not depart from the scope of the utility model and spirit in the case of, to above example Modify.The scope of the utility model is defined by the following claims.

Claims (10)

1. A kind of 1. audio output balancing circuitry, it is characterised in that

   Including impedance detection circuit, audio drive circuitry, resistance adjustment circuit, at least two audio output units；Wherein,

   Audio output and at least two audio output of the resistance adjustment circuit connected in series in the audio drive circuitry Between unit；

   To detect the institute of the resistance between the audio drive circuitry audio output and at least two audio output units respectively State the test side of impedance detection circuit and the audio output of the audio drive circuitry and at least two audio output list Member connection；Testing result for the test side according to the impedance detection circuit controls the resistance of the resistance adjustment circuit defeated The control output end of the impedance detection circuit gone out is connected with the resistance adjustment circuit.
2. 2. circuit according to claim 1, it is characterised in that the resistance adjustment circuit includes：At least two resistance are adjusted Economize on electricity road；And at least two resistance adjustments circuit and the one-to-one connection of at least two audio output units；

   The control output end of the impedance detection circuit be connected with the resistance adjustment circuit including：

   The control output end of the impedance detection circuit is connected with least two resistance adjustments circuit.
3. 3. circuit according to claim 2, it is characterised in that at least two audio output unit includes：First sound Frequency output unit and the second audio output unit；

   At least two resistance adjustments circuit includes：First resistor adjusts circuit and second resistance regulation circuit；

   At least two resistance adjustments circuit includes with the one-to-one connection of at least two audio output unit：

   Audio output and first audio output unit of the first resistor regulation circuit connected in series in audio drive circuitry Between；

   Audio output and second audio output unit of the second resistance regulation circuit connected in series in audio drive circuitry Between.
4. 4. circuit according to claim 3, it is characterised in that the output end of the audio drive circuitry includes：First sound Frequency output end and the second audio output；

   First resistor adjusts circuit connected in series between the audio output and first audio output unit of audio drive circuitry Including：

   First audio output and first audio output of the first resistor regulation circuit connected in series in audio drive circuitry Between unit；

   Audio output and second audio output unit of the second resistance regulation circuit connected in series in audio drive circuitry Between include：

   Second resistance adjusts second audio output and second audio output unit of the circuit connected in series in audio drive circuitry Between.
5. 5. the circuit according to claim 3 or 4, it is characterised in that the test side of the impedance detection circuit includes：First Test side and the second test side；

   Audio output and first audio output of the test side of the impedance detection circuit with the audio drive circuitry Unit and the connection of the second audio output unit include：

   First test side of the impedance detection circuit and the audio output of the audio drive circuitry and first audio Output unit connects, the second test side of the impedance detection circuit and the audio output of the audio drive circuitry and described Second audio output unit connects.
6. 6. according to the circuit described in claim any one of 1-4, it is characterised in that

   The resistance adjustment circuit includes digital regulation resistance.
7. 7. circuit according to claim 1, it is characterised in that

   The impedance detection circuit includes：Controlled switch, resistance measuring circuit, control circuit, the first end of the controlled switch The audio output of audio drive circuitry is connected, the second end connects the resistance measuring circuit, the control terminal connection control electricity Road；The resistance adjustment circuit and the resistance measuring circuit are connected with the control circuit；

   The control circuit, which is configured in, need to detect the audio drive circuitry audio output and at least two audio output lists During resistance between member, the controlled switch is controlled to turn on the audio output and resistance measurement electricity of the audio drive circuitry Circuit between road, and the resistance of the measurement result regulation resistance adjustment circuit fed back according to the resistance measuring circuit is defeated Go out.
8. 8. a kind of earphone, it is characterised in that including the circuit described in claim any one of 1-7.
9. 9. earphone according to claim 8, it is characterised in that also including earphone control chip, the impedance detection circuit It is integrated in earphone control chip.
10. 10. earphone according to claim 8, its feature exists, and the resistance adjustment circuit includes digital regulation resistance, the number Word potentiometer includes MAX5434 chips.