CN218734880U - Earphone switching circuit compatible with single-ended and balanced output - Google Patents

Earphone switching circuit compatible with single-ended and balanced output Download PDF

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Publication number
CN218734880U
CN218734880U CN202223020467.1U CN202223020467U CN218734880U CN 218734880 U CN218734880 U CN 218734880U CN 202223020467 U CN202223020467 U CN 202223020467U CN 218734880 U CN218734880 U CN 218734880U
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earphone
switch
pin
resistor
control module
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杨新云
李锦辉
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Shenzhen Shanling Digital Technology Development Co ltd
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Shenzhen Shanling Digital Technology Development Co ltd
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Abstract

The utility model discloses an earphone switching circuit compatible with single end and balanced output, which comprises an earphone socket, an earphone detection circuit, a switching module and a master control module, wherein the earphone socket and the master control module are connected with the earphone detection circuit and the switching module, so that the master control module controls the switching module to work according to earphone information detected by the earphone detection circuit; the switching module comprises a first switch, a second switch and a third switch, the main control module is respectively connected with the first switch, the second switch and the third switch, and the output ends of the first switch, the second switch and the third switch are connected with the earphone socket. The utility model relates to a compatible single-ended and balanced earphone switching circuit of output is through setting up the earphone detection circuitry and the switching module that all link to each other with earphone socket and host system respectively to make host system switch the operating condition of module work in order to control different switches respectively according to the earphone information control that detects, realize single-ended and balanced switching of output.

Description

Earphone switching circuit compatible with single-ended and balanced output
Technical Field
The utility model relates to an earphone circuit technical field especially relates to an earphone switching circuit of compatible single-ended and balanced output.
Background
The TRS and TRRS are two different types of earphone interfaces, and the TRS interface is also called a single-ended output interface and is used to drive a conventional earphone. The TRRS interface is called a balanced output interface and is matched with a balanced earphone for use, compared with the TRS interface, the TRRS interface is provided with one more contact for transmitting the audio signal of the microphone, and meanwhile, the separation degree of the left sound channel and the right sound channel can be effectively improved, and the left sound channel and the right sound channel are prevented from mutual interference through a ground wire.
The two earphone interfaces are not universal and only can identify the corresponding type of earphone, so in some electronic devices, in order to be able to use the two types of earphones, the two earphone interfaces are usually arranged, which undoubtedly increases the size of the product, increases the material cost and the processing cost of the product, and is very inconvenient especially in some electronic products which pursue miniaturization.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem that an earphone switching circuit of compatible single-ended and balanced output is provided to can realize single-ended output and balanced output two kinds of modes through setting up single earphone interface, can effectively reduce the product size.
In order to solve the technical problem, the purpose of the utility model is realized through following technical scheme: the earphone switching circuit comprises an earphone socket, an earphone detection circuit, a switching module and a main control module, wherein the earphone socket and the main control module are connected with the earphone detection circuit and the switching module, so that the main control module controls the switching module to work according to earphone information detected by the earphone detection circuit; the switching module comprises a first switch, a second switch and a third switch, the main control module is respectively connected with the first switch, the second switch and the third switch, and the output ends of the first switch, the second switch and the third switch are connected with the earphone socket.
The further technical scheme is as follows: the earphone socket comprises an interface and six signal pins which are respectively connected with the interface, namely a ground signal pin, a balanced output right negative channel signal pin, a balanced output left negative channel signal pin, a right channel signal pin, a left channel signal pin and a detection signal pin.
The further technical scheme is as follows: the earphone detection circuit comprises an earphone insertion detection circuit, the earphone insertion detection circuit comprises a fourth resistor, a fifth resistor and a sixth resistor, one ends of the fifth resistor and the sixth resistor are connected with a sixth capacitor connected with the ground one by one, the other end of the fifth resistor is connected with the detection signal pin, the other end of the sixth resistor is connected with the earphone insertion detection end of the master control module, the sixth resistor and one end of the fifth resistor are connected with one end of the fourth resistor, the other end of the fourth resistor is connected with the 3.3V voltage end, and the other end of the sixth resistor is connected with the fifth capacitor connected with the ground one by one.
The further technical scheme is as follows: the earphone detection circuit further comprises an earphone type detection circuit, the earphone type detection circuit comprises a ninth resistor, a tenth resistor and an eleventh resistor, one ends of the tenth resistor and the eleventh resistor are connected with a ninth capacitor which is connected with the ground one by one, the other end of the tenth resistor is connected with the balanced output right negative sound channel signal pin, the other end of the eleventh resistor is connected with the balanced earphone detection end of the main control module, one ends of the tenth resistor and the eleventh resistor are connected with one end of the ninth resistor, the other end of the ninth resistor is connected with the 3.3V voltage end, and the other end of the eleventh resistor is connected with an eighth capacitor which is connected with the ground one by one.
The further technical scheme is as follows: the first switch is respectively connected with the left sound channel signal pin and the right sound channel signal pin, the second switch is respectively connected with the balanced output left negative sound channel signal pin and the balanced output right negative sound channel signal pin, and the third switch is connected with the ground end signal pin.
The further technical scheme is as follows: the first switch adopts the switch chip that the model is SGM3714, the second switch with the third switch all adopts the switch chip that the model is RT 1238Q.
The further technical scheme is as follows: the earphone control signal end of the master control module is connected with an input pin of the first switch through a third resistor, an enable pin of the first switch is connected with a 3.3V voltage end through a second resistor, a power supply voltage pin of the first switch is connected with the 3.3V voltage end through a first resistor, a first data pin and a second data pin of the first switch are respectively connected with the left sound channel signal foot and the right sound channel signal foot, and a first signal source pin and a second signal source pin of the first switch are respectively connected with the earphone output left sound channel end and the earphone output right sound channel end of the master control module.
The further technical scheme is as follows: the voltage pin of the second switch is connected with the 3.3V voltage end through a seventh resistor, the selection pin of the second switch is connected with the balanced output control end of the main control module after passing through an eighth resistor, the first right sound channel pin of the second switch is connected with the earphone control ground end of the main control module, the second left sound channel pin and the second right sound channel pin of the second switch are respectively connected with the left negative sound channel end of the output balance output of the main control module and the right negative sound channel end of the output balance output of the ear amplifier, and the left sound channel pin and the right sound channel pin of the second switch are respectively connected with the left negative sound channel signal pin of the balanced output and the right negative sound channel signal pin of the balanced output.
The further technical scheme is as follows: and a voltage pin of the third switch is connected with a 3.3V voltage end through a twelfth resistor, a selection pin of the third switch is connected with an earphone control signal end of the main control module, a second left sound channel pin and a second right sound channel pin of the third switch are both grounded, and a left sound channel pin and a right sound channel pin of the third switch are both connected with an earphone control ground end of the main control module.
The further technical scheme is as follows: the interface adopts a six-end interface with the model number of PJK-2028D-6P to be respectively connected with the six signal pins.
The utility model has the advantages of: the utility model relates to a compatible single-ended and balanced earphone switching circuit of output all links to each other switch module and earphone detection circuitry with earphone socket and host system respectively through setting up, so that host system controls the switch module work according to the earphone information that earphone detection circuitry detected, thereby control the operating condition of first switch, second switch and third switch respectively, put the connection break-make of output with host system's ear with the different signal foot of control earphone socket, realize the switching of single-ended output and balanced output, make single earphone socket can compatible single-ended output and balanced output two kinds of operating modes, can compatible conventional earphone and balanced earphone two kinds of equipment, good compatibility has, need not to set up two kinds of earphone sockets on the same electronic product respectively, can effectively reduce the product size, save material cost and processing cost, be applicable to miniaturized electronic product; meanwhile, the circuit is simple in structure, convenient to set, low in cost and convenient to control.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced 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 any creative effort.
Fig. 1 is a block diagram of an earphone switching circuit compatible with single-ended and balanced output according to an embodiment of the present invention;
fig. 2 is a schematic circuit diagram of an earphone jack of an earphone switching circuit compatible with single-ended and balanced output according to an embodiment of the present invention;
fig. 3 is a schematic circuit diagram of an earphone detection circuit of an earphone switching circuit compatible with single-ended and balanced output according to an embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a first switch of an earphone switching circuit compatible with single-ended and balanced output according to an embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a second switch of an earphone switching circuit compatible with single-ended and balanced output according to an embodiment of the present invention;
fig. 6 is a schematic circuit diagram of a third switch of an earphone switching circuit compatible with single-ended and balanced output according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of an earphone jack of an earphone switching circuit compatible with single-ended and balanced output according to an embodiment of the present invention;
fig. 8 is a schematic diagram of the connection between the earphone socket shown in fig. 7 and a three-section earphone.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, of the 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.
Referring to fig. 1 to 8, fig. 1 is a block diagram of an earphone switching circuit compatible with single-ended and balanced output according to an embodiment of the present invention, where the earphone switching circuit 10 compatible with single-ended and balanced output includes an earphone socket 11, an earphone detection circuit 12, a switching module 14 and a main control module 13, the earphone socket 11 is respectively connected to the earphone detection circuit 12 and the switching module 14, and the main control module 14 is respectively connected to the earphone detection circuit 12 and the switching module 14, so that the main control module 14 controls the switching module 14 to operate according to earphone information detected by the earphone detection circuit 12; the switching module 14 includes a first switch U1, a second switch U2 and a third switch U3, the main control module 13 is connected to the first switch U1, the second switch U2 and the third switch U3, respectively, and output ends of the first switch U1, the second switch U2 and the third switch U3 are connected to the earphone socket 11.
The main control module 13 is connected to the earphone socket 11 through the earphone detection circuit 12 and the switching module 14, the main control module 13 may include an ear amplifier unit, the ear amplifier unit is connected to each signal pin of the earphone socket 11 through each switch of the switching module 14, and the main control module 13 controls on/off of each switch of the switching module 14 according to the earphone information obtained by the earphone detection circuit 12 to control whether each signal pin outputs a signal, so as to control signal output according to the earphone type, and realize switching between single-ended output and balanced output. The earphone information includes earphone insertion information and earphone type information, the earphone insertion information refers to information generated by inserting an earphone, and the earphone type information includes two types, namely a conventional earphone and a balance earphone. Different signal pins of the earphone socket 11 can feed back different earphone information, part of the signal pins can feed back information whether the earphone is plugged into the earphone socket or not to the main control module, and part of the signal pins can be used for feeding back earphone type information. The earphone socket 11 is an earphone socket of five-section 3.5mm earphones, and is used for inserting and connecting three-section, four-section and five-section 3.5mm earphones, the earphone detection circuit 12 is respectively electrically connected with the earphone socket 11 and the main control module 13 and is used for detecting whether the earphone socket 11 is provided with earphones or not and detecting the type of the inserted earphones, then the detection result is transmitted to the main control module 13, the switching module 14 is respectively connected with the main control module 13 and the earphone socket 11, and the working states of the first switch U1, the second switch U2 and the third switch U3 are controlled by the main control module according to the detection result, so that the connection and disconnection of different signal pins of each switch and the earphone socket 11 are controlled, and whether the corresponding signal pin outputs signals or not is controlled. The main control module 13 can be connected to a power supply, and the earphone detection circuit 12, the switching module 14 and the earphone socket 11 are connected to the power supply through the main control module 13 to provide a working power supply for the earphone detection circuit 12, the switching module 14 and the earphone socket 11. The earphone switching circuit 10 compatible with single-ended and balanced output is provided with the switching module 14 and the earphone detection circuit 12 which are respectively connected with the earphone socket 11 and the main control module 13, so that the main control module 13 controls the switching module 14 to work according to earphone information detected by the earphone detection circuit 12, and then the working states of the first switch U1, the second switch U2 and the third switch U3 are respectively controlled, so that the connection and disconnection of different signal pins of the earphone socket 11 and the ear discharge output of the main control module 13 are controlled, the switching of single-ended output and balanced output is realized, a single earphone socket 11 can be in a single-ended compatible output and balanced output working mode, two devices of a conventional earphone (namely a single-ended earphone) and a balanced earphone can be compatible, the earphone switching circuit has good compatibility, two earphone sockets 11 do not need to be respectively arranged on the same electronic product, the product size can be effectively reduced, the material cost and the processing cost are saved, and the switching circuit is suitable for a miniaturized electronic product; meanwhile, the circuit is simple in structure, convenient to set, low in cost and convenient to control.
Specifically, in the present embodiment, with reference to fig. 2, fig. 7 and fig. 8, the earphone jack 11 includes an interface J1 and six signal pins respectively connected to the interface J1, which are a ground pin GND, a balanced output right negative channel signal pin HP _ R, a balanced output left negative channel signal pin HP _ L, a right channel signal pin HP _ R, a left channel signal pin HP _ L and a detection signal pin HS _ DET _ SW. When the earphone is inserted, the connectors of the earphone are connected with the signal pins, the output of the signal pins of the earphone socket 11 can be switched by controlling the connection and disconnection of the switches of the switching module 14 and the signal pins according to the type of the earphone, when the earphone socket 11 is inserted with a 3.5mm earphone connected with three sections, the ground signal pin GND and the balanced output right negative channel signal pin HP _ R are connected with the ground end of the earphone connector of the 3.5mm earphone, the balanced output left negative channel signal pin HP _ L and the balanced output right channel signal pin HP _ R are connected with the right channel end of the earphone connector of the 3.5mm earphone, and the left channel signal pin HP _ L and the detection signal pin HS _ DET _ SW are connected with the left channel end of the earphone connector of the 3.5mm earphone; when the earphone socket 11 is inserted and connected with four sections of 3.5mm earphones, a ground signal pin GND is connected with an MIC end of an earphone connector of the four sections of 3.5mm earphones, a balanced output right negative channel signal pin HP _ R is connected with a ground end of an earphone connector of the four sections of 3.5mm earphones, a balanced output left negative channel signal pin HP _ L and a balanced output right channel signal pin HP _ R are both connected with a right channel end of an earphone connector of the four sections of 3.5mm earphones, a left channel signal pin HP _ L is connected with a left channel end of an earphone connector of the four sections of 3.5mm earphones, and a detection signal pin HS _ DET _ SW is connected with a switch end of an earphone connector of the four sections of 3.5mm earphones; when the earphone socket 11 is inserted and connected with five sections of 3.5mm earphones, the ground signal pin GND is connected with the MIC/GND end of the earphone connector of the five sections of 3.5mm earphones, the balanced output right negative channel signal pin HP _ R is connected with the balanced output right negative channel end of the earphone connector of the five sections of 3.5mm earphones, the balanced output left negative channel signal pin HP _ L is connected with the balanced output left negative channel end of the earphone connector of the five sections of 3.5mm earphones, the right channel signal pin HP _ R is connected with the right channel end of the earphone connector of the five sections of 3.5mm earphones, the left channel signal pin HP _ L is connected with the left channel end of the earphone connector of the five sections of 3.5mm earphones, and the detection signal pin HS _ DET _ SW is connected with the switch end of the earphone connector of the five sections of 3.5mm earphones.
Preferably, the interface J1 adopts a six-terminal interface with the model number PJK-2028D-6P to be respectively connected with the six signal pins.
With continuing reference to fig. 2 to fig. 6, in particular, in this embodiment, the earphone detection circuit 12 includes an earphone insertion detection circuit 121, the earphone insertion detection circuit 121 includes a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, one end of the fifth resistor R5 and one end of the sixth resistor R6 are connected to the sixth capacitor C6 that is connected to ground one by one, the other end of the fifth resistor R5 is connected to the detection signal pin HS _ DET _ SW, the other end of the sixth resistor R6 is connected to the earphone insertion detection end HS _ DET _ PO of the main control module 13, one end of each of the sixth resistor R6 and the fifth resistor R5 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to a 3.3V voltage terminal, and the other end of the sixth resistor R6 is connected to the fifth capacitor C5 that is connected to ground one by one. When no earphone is inserted, the detection signal pin HS _ DET _ SW is disconnected from the left channel signal pin HP _ L, and the earphone insertion detection end HS _ DET _ PO of the main control module 13 detects a high level; when the headphone is plugged in, the detection signal pin HS _ DET _ SW and the left channel signal pin HP _ L are short-circuited, and the headphone plugging detection end HS _ DET _ PO of the main control module 13 detects a low level. The high and low levels can be determined according to seven tenth of 3.3V voltage signals, i.e., the high voltage can refer to a voltage signal greater than 2.31V, and the low level can refer to a voltage signal not greater than 2.31V.
Specifically, in this embodiment, the earphone detection circuit 12 further includes an earphone type detection circuit 122, the earphone type detection circuit 122 includes a ninth resistor R9, a tenth resistor R10, and an eleventh resistor R11, one end of the tenth resistor R10 is connected to one end of the eleventh resistor R11 and then connected to a ninth capacitor C9 that is grounded, the other end of the tenth resistor R10 is connected to the balanced output right negative channel signal pin HP _ R-, the other end of the eleventh resistor R11 is connected to a balanced earphone detection terminal HS _ DET _ BAL of the main control module 13, one end of each of the tenth resistor R10 and the eleventh resistor R11 is connected to one end of the ninth resistor R9, the other end of the ninth resistor R9 is connected to the 3.3V voltage terminal, and the other end of the eleventh resistor R11 is connected to an eighth capacitor C8 that is grounded. When the main control module 13 knows that an earphone is inserted through the earphone insertion detection circuit 121, the earphone type information of the inserted earphone is detected and acquired through the earphone type detection circuit 122, and when five sections of 3.5mm earphones are inserted, the balanced output right negative channel signal pin HP _ R-is connected with the balanced output right negative channel end of the earphone connector of the inserted earphone, at this time, the balanced earphone detection end HS _ DET _ BAL of the main control module 13 obtains a high level, and then the main control module 13 can know that the earphone type information of the inserted earphone is a balanced earphone; when three or four sections of 3.5mm earphones are inserted, the balanced output right negative channel signal pin HP _ R-is connected with the ground end of the earphone connector inserted into the earphones, at the moment, the balanced earphone detection end HS _ DET _ BAL of the main control module 13 obtains a low level, and then the main control module 13 can know that the type information of the earphones inserted into the earphones is conventional earphones. The high and low levels can be determined according to seven tenth of 3.3V voltage signals, i.e. the high voltage can refer to a voltage signal greater than 2.31V, and the low level can refer to a voltage signal not greater than 2.31V.
Specifically, the first switch U1 is connected to the left channel signal pin HP _ L and the right channel signal pin HP _ R, the second switch U2 is connected to the balanced output left negative channel signal pin HP _ L and the balanced output right negative channel signal pin HP _ R, and the third switch U3 is connected to the ground terminal signal pin GND.
Specifically, the first switch U1 adopts a switch chip with a model number of SGM3714, and the second switch U2 and the third switch U3 both adopt switch chips with a model number of RT 1238Q.
Specifically, an input pin IN of the first switch U1 is connected to an earphone control signal terminal PO _ MUTE of the main control module 13 through a third resistor R3, an enable pin EN of the first switch U1 is connected to a 3.3V voltage terminal through a second resistor R2, a power supply voltage pin VCC of the first switch U1 is connected to the 3.3V voltage terminal through the first resistor R1, a first data pin D1 and a second data pin D2 of the first switch U1 are used as signal outputs and are respectively connected to the left channel signal pin HP _ L and the right channel signal pin HP _ R, and a first signal source pin S1 and a second signal source pin S2 of the first switch U1 are used as signal inputs and are respectively connected to an ear-play output left channel terminal HP _ LP and an ear-play output right channel terminal HP _ R of the main control module 13.
Specifically, a voltage pin VDD of the second switch U2 is connected to a 3.3V voltage end through a seventh resistor R7, a selection pin SEL of the second switch U2 is connected to a balanced output control end BAL _ MUTE of the main control module 13 through an eighth resistor R8, a first right channel pin R1 of the second switch U2 is connected to an earphone control ground end PO _ GND of the main control module 13, a second left channel pin L2 and a second right channel pin R2 of the second switch U2 are respectively connected to an aural output balanced left negative channel end HP _ LN and an aural output balanced right negative channel end HP _ RN of the main control module 13, and a left channel pin L and a right channel pin R of the second switch U2 are respectively connected to the balanced output left negative channel signal pin HP _ L-and the balanced output right negative channel signal pin HP _ R-.
Specifically, a voltage pin VDD of the third switch U3 is connected to a 3.3V voltage terminal through a twelfth resistor R12, a selection pin SEL of the third switch U3 is connected to an earphone control signal terminal PO _ MUTE of the main control module 13, a second left channel pin L2 and a second right channel pin R2 of the third switch U3 are both grounded, and a left channel pin L and a right channel pin R of the third switch U3 are both connected to an earphone control ground terminal PO _ GND of the main control module 13. The earphone control ground terminal PO _ GND of the main control module 13 may be used to control the pins connected to the earphone control ground terminal PO _ GND to be grounded, and the ground terminal signal pin GND of the interface J1 of the earphone socket 11 may be used to be grounded.
The on/off of the first switch U1 and the third switch U3 is controlled by the earphone control signal terminal PO _ MUTE of the main control module 13 according to whether an earphone is inserted, so as to control whether to output a signal to the signal pin of the corresponding earphone socket 11. When detecting that an earphone is inserted, the main control module 13 controls the earphone control signal terminal PO _ MUTE to output a high level signal to control the first switch U1 and the third switch U3 to be turned on, so that the output signal of the earphone amplifier can be output to the signal pin of the corresponding earphone socket 11. The on-off of the second switch U2 is controlled by the balanced output control end BAL _ MUTE of the main control module 13 according to the earphone type information, when it is detected that the earphone type information is a conventional earphone (single-ended earphone), the balanced output control end BAL _ MUTE of the main control module 13 outputs a low level, the second switch U2 is turned off, so that the corresponding output signal of the ear amplifier cannot be output to the signal pin of the corresponding earphone socket 11 through the second switch U2, and the output mode of the switching module 14 is a single-ended output mode; when detecting that the earphone type information is a balanced earphone, the balanced output control terminal BAL _ MUTE of the main control module 13 outputs a high level, and the second switch U2 is turned on, so that the corresponding output signal of the ear amplifier is output to the signal pin of the corresponding earphone socket 11 through the second switch U2, and the output mode of the switching module 14 is a balanced output mode, thereby realizing the switching between single-ended and balanced output.
Based on the design, in operation, the earphone insertion detection circuit of the earphone detection circuit detects whether an earphone is inserted and outputs a detection result to the main control module according to the states of the detection signal pin of the earphone socket and the left sound channel signal pin, when no earphone is inserted, the detection signal pin is disconnected with the left sound channel signal pin, the earphone detection circuit detects that the level of the detection signal pin is high, the earphone is not inserted, the earphone insertion detection end of the main control module obtains a high level, the first switch, the second switch and the third switch are controlled to be disconnected completely, the earphone switching circuit compatible with single end and balanced output is in a mute state, and control is finished. When an earphone is inserted, the detection signal pin is in short circuit with the left channel signal pin, the earphone detection circuit detects that the level change of the detection signal pin is low, the earphone is inserted, the earphone insertion detection end of the main control module obtains low level, the first switch, the second switch and the third switch are controlled to be completely disconnected, the earphone switching circuit compatible with single-ended and balanced output is in a mute state, then, the earphone type detection circuit detects that the level change of the balanced output right negative channel signal pin of the earphone socket is obtained and outputs a detection result to the main control module, when three sections or four sections of 3.5mm earphones with microphones are inserted, the balanced earphone detection end of the main control module obtains low level, the earphones are identified to be single-ended earphones, the main control module controls the first switch and the third switch to be closed, the second switch is controlled to be disconnected, the left channel signal pin connected with the output end of the first switch is communicated with the right channel signal pin, but the balanced output left negative channel signal pin and the balanced output right channel signal pin of the second switch are disconnected, so that the balanced output single-ended switching circuit compatible single-ended and the balanced earphone output single-ended switching circuit is switched to be switched; when five sections of 3.5mm earphones are inserted, the balance earphone detection end of the main control module obtains high level, the main control module identifies and knows that the earphones are balance output earphones, the main control module controls the first switch, the second switch and the third switch to be closed, then a left sound channel signal pin and a right sound channel signal pin which are connected with the output end of the first switch are communicated, and a balance output left negative sound channel signal pin and a balance output right negative sound channel signal pin of the second switch are communicated, so that the earphone switching circuit of the compatible and balance output earphones is switched into balance output.
To sum up, the utility model relates to a compatible single-ended and balanced earphone switching circuit is through setting up switching module and the earphone detection circuitry that all links to each other with earphone socket and host system respectively, so that host system controls the work of switching module according to the earphone information that earphone detection circuitry detected, thereby control the operating condition of first switch, second switch and third switch respectively, in order to control the connection break-make of the different signal feet of earphone socket and host system's ear amplifier output, realize the switching of single-ended and balanced output, make single earphone socket can compatible single-ended output and balanced output two kinds of operating modes, can compatible conventional earphone and balanced earphone two kinds of equipment, have good compatibility, need not to set up two kinds of earphone sockets respectively on the same electronic product, can effectively reduce the product size, save material cost and processing cost, be applicable to miniaturized electronic product; meanwhile, the circuit is simple in structure, convenient to set, low in cost and convenient to control.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope of the present invention, and these modifications or replacements should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. The earphone switching circuit compatible with single-ended and balanced output is characterized by comprising an earphone socket, an earphone detection circuit, a switching module and a main control module, wherein the earphone socket and the main control module are connected with the earphone detection circuit and the switching module so that the main control module controls the switching module to work according to earphone information detected by the earphone detection circuit; the switching module comprises a first switch, a second switch and a third switch, the main control module is respectively connected with the first switch, the second switch and the third switch, and the output ends of the first switch, the second switch and the third switch are connected with the earphone socket.
2. The circuit of claim 1, wherein the earphone jack comprises an interface and six signal pins respectively connected to the interface, the six signal pins being a ground pin, a balanced output right negative channel pin, a balanced output left negative channel pin, a right channel pin, a left channel pin, and a detection pin.
3. The earphone switching circuit compatible with single-ended and balanced output according to claim 2, wherein the earphone detection circuit comprises an earphone insertion detection circuit, the earphone insertion detection circuit comprises a fourth resistor, a fifth resistor and a sixth resistor, one end of the fifth resistor and one end of the sixth resistor are connected to a sixth capacitor connected to ground one by one, the other end of the fifth resistor is connected to the detection signal pin, the other end of the sixth resistor is connected to the earphone insertion detection end of the main control module, one end of each of the sixth resistor and the fifth resistor is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to the 3.3V voltage end, and the other end of the sixth resistor is connected to a fifth capacitor connected to ground one by one.
4. The earphone switching circuit compatible with single-ended and balanced output according to claim 3, wherein the earphone detection circuit further includes an earphone type detection circuit, the earphone type detection circuit includes a ninth resistor, a tenth resistor and an eleventh resistor, one end of the tenth resistor and one end of the eleventh resistor are connected to a ninth capacitor connected to ground one by one, the other end of the tenth resistor is connected to the balanced output right negative channel signal pin, the other end of the eleventh resistor is connected to the balanced earphone detection end of the main control module, one end of each of the tenth resistor and the eleventh resistor is connected to one end of the ninth resistor, the other end of the ninth resistor is connected to the 3.3V voltage end, and the other end of the eleventh resistor is connected to an eighth capacitor connected to ground one by one.
5. The earphone switching circuit according to claim 2, wherein the first switch is connected to the left channel signal pin and the right channel signal pin, the second switch is connected to the balanced output left negative channel signal pin and the balanced output right negative channel signal pin, and the third switch is connected to the ground signal pin.
6. The earphone switching circuit compatible with single-ended and balanced output according to claim 5, wherein the first switch is a switch chip with model number SGM3714, and the second switch and the third switch are both switch chips with model number RT 1238Q.
7. The earphone switching circuit compatible with single-ended and balanced output according to claim 6, wherein an input pin of the first switch is connected to the earphone control signal terminal of the main control module through a third resistor, an enable pin of the first switch is connected to the 3.3V voltage terminal through a second resistor, a supply voltage pin of the first switch is connected to the 3.3V voltage terminal through a first resistor, a first data pin and a second data pin of the first switch are respectively connected to the left channel signal pin and the right channel signal pin, and a first signal source pin and a second signal source pin of the first switch are respectively connected to the left audio output terminal and the right audio output terminal of the main control module.
8. The earphone switching circuit compatible with single-ended and balanced output according to claim 6, wherein a voltage pin of the second switch is connected to a 3.3V voltage terminal through a seventh resistor, a selection pin of the second switch is connected to a balanced output control terminal of the main control module through an eighth resistor, a first right channel pin of the second switch is connected to an earphone control ground terminal of the main control module, a second left channel pin and a second right channel pin of the second switch are respectively connected to an aural output balanced left negative channel terminal and an aural output balanced right negative channel terminal of the main control module, and a left channel pin and a right channel pin of the second switch are respectively connected to the balanced output left negative channel signal pin and the balanced output right negative channel signal pin.
9. The earphone switching circuit compatible with single-ended and balanced output according to claim 6, wherein the voltage pin of the third switch is connected to the 3.3V voltage terminal via a twelfth resistor, the selection pin of the third switch is connected to the earphone control signal terminal of the main control module, the second left channel pin and the second right channel pin of the third switch are both grounded, and the left channel pin and the right channel pin of the third switch are both connected to the earphone control ground terminal of the main control module.
10. The earphone switching circuit compatible with single-ended and balanced output according to claim 2, wherein the interface is a six-terminal interface of model PJK-2028D-6P to connect with six signal pins, respectively.
CN202223020467.1U 2022-11-11 2022-11-11 Earphone switching circuit compatible with single-ended and balanced output Active CN218734880U (en)

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Application Number Priority Date Filing Date Title
CN202223020467.1U CN218734880U (en) 2022-11-11 2022-11-11 Earphone switching circuit compatible with single-ended and balanced output

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202223020467.1U CN218734880U (en) 2022-11-11 2022-11-11 Earphone switching circuit compatible with single-ended and balanced output

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CN218734880U true CN218734880U (en) 2023-03-24

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