CN111698614B

CN111698614B - Audio output circuit and electronic equipment

Info

Publication number: CN111698614B
Application number: CN202010458312.2A
Authority: CN
Inventors: 庞凤颖
Original assignee: Goertek Optical Technology Co Ltd
Current assignee: Goertek Optical Technology Co Ltd
Priority date: 2020-05-25
Filing date: 2020-05-25
Publication date: 2021-10-26
Anticipated expiration: 2040-05-25
Also published as: CN111698614A

Abstract

The invention discloses an audio output circuit and electronic equipment, the circuit includes: the audio socket comprises an audio jack, a grounding pin arranged in the audio jack, a first external detection pin and a second external detection pin, wherein the grounding pin and the first external detection pin are mutually abutted when a male connector of external equipment is inserted into the audio jack; the grounding pin is also physically connected with a second external detection pin through a male head of the external equipment; the two detection ends of the peripheral detection trigger module are respectively connected with the first peripheral detection pin and the second peripheral detection pin; the peripheral detection trigger module is used for outputting corresponding detection signals according to level signals output by the first peripheral detection pin and the second peripheral detection pin; and the audio output control module is used for determining the type of the external equipment according to the detection signal output by the peripheral detection trigger module and outputting an audio signal corresponding to the external equipment. The invention solves the problem that the audio output circuit can not realize the compatibility of the digital sound box and the analog sound box.

Description

Audio output circuit and electronic equipment

Technical Field

The present invention relates to the field of audio technologies, and in particular, to an audio output circuit and an electronic device.

Background

With the development of speaker technology, more and more digital speakers are used by consumers, and digital audio signals are decoders in digital speakers or earphones with D/a conversion function by transmitting the digital audio signals to the digital speakers through an SPDIF interface. More and more digital speakers choose to transmit digital sound signals over SPDIF interfaces. The existing electronic equipment can only be adapted to one external equipment, and the compatibility of a digital sound box and an analog sound box cannot be realized.

Disclosure of Invention

The invention mainly aims to provide an audio output circuit and electronic equipment, and aims to solve the problem that the electronic equipment can only be adapted to one external device and cannot realize the compatibility of a digital sound box and an analog sound box.

In order to achieve the above object, the present invention provides an audio output circuit, including:

an audio socket, the audio socket comprising an audio jack, a ground pin disposed in the audio jack, a first peripheral detection pin and a second peripheral detection pin, wherein,

the grounding pin and the first peripheral detection pin are mutually abutted when a male head of an external device is inserted into the audio jack; the grounding pin is also physically connected with the second external detection pin through a male head of an external device;

the detection end of the peripheral detection trigger module is respectively connected with the first peripheral detection pin and the second peripheral detection pin; the peripheral detection trigger module is used for outputting corresponding detection signals according to the level signals output by the first peripheral detection pin and the second peripheral detection pin;

and the audio output control module is used for determining the type of the external equipment according to the detection signal output by the peripheral detection trigger module and outputting an audio signal corresponding to the external equipment.

Optionally, the grounding pin has elasticity, and when a male plug of an external device is inserted into the audio jack, the grounding pin is pushed by the male plug of the external device and abuts against the first external detection pin; when the male plug of the external equipment is pulled out of the audio jack, the grounding pin is elastically restored and is separated from the audio socket detection pin;

the second external detection pin is electrically connected with the grounding pin through a male head of the external equipment when the external equipment is analog audio equipment; and when the external equipment is digital audio equipment, the external equipment is in insulated connection with the grounding pin through the male head of the external equipment.

Optionally, the peripheral detection triggering module outputs an analog detection signal when the signals output by the first peripheral detection pin and the second peripheral detection pin are both at a low level;

and outputting a digital detection signal when the signal output by the first peripheral detection pin is at a low level and the signal output by the second peripheral detection pin is at a high level.

Optionally, a left audio channel pin, a right audio channel pin and a digital audio output pin are further disposed in the audio jack;

the audio output control module is specifically used for converting the accessed digital audio signals into analog audio signals and outputting the analog audio signals through the left channel pin and the right channel pin when the analog detection signals are received;

and outputting the accessed digital audio signal through a digital audio output pin when the digital detection signal is received.

Optionally, the peripheral detection trigger module includes a nand logic gate and an or logic gate, a first input end of the nand logic gate is connected to the first peripheral detection pin, a second input end of the nand logic gate is connected to the second peripheral detection pin, and an output end of the nand logic gate is connected to the first signal feedback end of the audio output control module;

the first input end of the OR logic gate is connected with the first peripheral detection pin, the second input end of the OR logic gate is connected with the second peripheral detection pin, and the output end of the OR logic gate is connected with the second signal feedback end of the audio output control module.

Optionally, the peripheral detection trigger module further includes a first signal indication circuit, and a controlled end of the first signal indication circuit is connected to the output end of the nand logic gate; wherein the content of the first and second substances,

the first signal indicating circuit comprises a first switch tube, a first pull-up resistor, a second pull-up resistor and a first LED lamp, wherein the controlled end of the first switch tube is the controlled end of the first signal indicating circuit, the output end of the first switch tube is connected with the cathode of the first LED lamp and the first end of the first pull-up resistor, the first switch tube is connected with a first direct current power supply through the first pull-up resistor, and the input end of the first switch tube is grounded; the second of the first pull-up resistor is connected with a first direct current power supply; and the anode of the first LED lamp is connected with the first direct current power supply through the second pull-up resistor.

Optionally, the peripheral detection trigger module further includes a second signal indication circuit, and a controlled end of the second signal indication circuit is connected to the or logic gate; wherein the content of the first and second substances,

the second signal indicating circuit comprises a second switch tube, a third pull-up resistor and a second LED lamp, the controlled end of the second switch tube is the controlled end of the second signal indicating circuit, the input end of the second switch tube is grounded, and the output end of the second switch tube is connected with the anode of the second LED lamp through the third pull-up resistor; and the cathode of the second LED lamp is grounded.

Optionally, the audio output circuit further includes a digital audio signal output circuit, the digital audio signal output circuit includes a first voltage-dividing resistor, a second voltage-dividing resistor and a transmitting module 12 integrated in the audio jack, a first end of the first voltage-dividing resistor is connected to the output end of the audio output control module, a second end of the first voltage-dividing resistor is grounded via the second voltage-dividing resistor, and a common end of the first voltage-dividing resistor and the second voltage-dividing resistor is connected to a digital audio output pin integrated in the audio jack.

Optionally, the audio output circuit further includes a power switch circuit, a controlled end of the power switch circuit is connected to the output end of the first signal indication circuit, an input end of the power switch circuit is connected to the first direct current power supply, and an output end of the power switch circuit is connected to the power end of the transmitting module 12.

The invention also provides an electronic device comprising the audio output circuit.

The audio output circuit provided by the invention has the advantages that the mutual butting of the grounding pin and the first external detection pin is realized by arranging the audio socket and utilizing the grounding pin in the audio jack when the male head of the external equipment is inserted into the audio jack, and the physical connection of the grounding pin and the second external detection pin is realized by the male head of the external equipment. And setting a peripheral detection trigger module to detect the level change of a first peripheral detection pin and a second peripheral detection pin arranged in the audio socket. That is, whether the audio socket has the external device to be connected is determined according to whether the second external device detection pin is electrically connected with the grounding pin. And when equipment is accessed, determining the type of the accessed external equipment, and outputting corresponding detection signals so as to select audio signals of corresponding modes to output according to different types of external equipment. The audio output circuit can output digital audio signals and analog audio signals, is compatible with different audio equipment and outputs audio signals corresponding to external equipment. The invention solves the problem that the electronic equipment can only be adapted to one external device and can not realize the compatibility of the digital sound box and the analog sound box.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a functional block diagram of an audio output circuit according to the present invention;

FIG. 2 is a circuit diagram of the audio output circuit of FIG. 1 according to an embodiment;

FIG. 3 is a schematic circuit diagram of an embodiment of a digital audio output circuit of the audio output circuit of FIG. 1;

fig. 4 is a schematic structural diagram of an embodiment of a male connector of an external device.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	Audio socket	A_SPDIF_OUT	Digital audio output pin
20	Peripheral detection trigger module	A_HP_R	Right sound channel foot
				30	Audio output control module	A_HP_IN	First peripheral equipment detection pin
40	Audio processing module	A_HP_S	Second peripheral detection pin
				50	Digital audio signal output circuit	A_HP_L	Left sound track foot
Q1～Q3	First to third switching tubes	GND	Grounding pin
				NAND	NAND logic gate	OR1	OR logic gate

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The invention provides an audio output circuit, which is applied to electronic equipment with an audio playing system, such as an android television, a desktop computer, a portable computer, a mobile phone and the like.

The electronic equipment can play audio signals by itself, and can also play audio by external equipment such as an external sound box, an earphone and the like. The conventional audio signal transmission is performed in an analog manner, and a specific process is that an audio processing device of an electronic device, for example, digital sound (including WAV, MP3, CD, etc.) on a computer is D/a converted by a chip (multimedia digital signal codec) on a sound card, and then output to a common multimedia speaker, and finally heard by our ear. However, serious electromagnetic waves still exist in the computer case, and D/A, A/D conversion still suffers from serious signal interference.

With the development of speaker technology, more and more digital speakers are used by consumers, and digital audio signals are decoders in digital speakers or earphones with D/a conversion function by transmitting the digital audio signals to the digital speakers through an SPDIF interface. That is, when playing computer sound file, the step of D/A conversion is not carried OUT, the digital signal is directly output to the inside of the digital sound box through the SPDIF OUT interface of the sound card, and D/A conversion is carried OUT in the sound box, thereby reducing electromagnetic wave with serious interference in the case and purifying the tone quality. SPDIF is divided into coaxial and optical fiber as transmission carriers, and the signals transmitted by the coaxial and optical fiber are the same, and the differences are that the carriers are different, and the interfaces and the connecting lines are different in appearance. The optical signal transmission has the characteristics of no need of considering interface level and impedance problems, flexible interface and stronger anti-interference capability. Therefore, more and more digital speakers choose to transmit digital sound signals through the SPDIF interface.

The existing electronic equipment can only be adapted to one external equipment, and the compatibility of a digital sound box and an analog sound box cannot be realized. Therefore, how to realize the recognition and switch the audio output effectively and freely becomes an urgent problem to be solved.

In order to solve the above problem, referring to fig. 1 to 4, in an embodiment of the present invention, the audio output circuit includes:

an audio jack 10, the audio jack 10 comprising an audio jack 11, a ground pin GND disposed IN the audio jack 11, a first peripheral detection pin A _ HP _ IN and a second peripheral detection pin A _ HP _ S, wherein,

the ground pin GND and the first peripheral detection pin a _ HP _ IN are mutually abutted when a male connector of an external device is inserted into the audio jack 11; the grounding pin GND is also physically connected with the second external detection pin A _ HP _ S through a male head of an external device;

the peripheral detection trigger module 20 has two detection ends respectively connected to the first peripheral detection pin a _ HP _ IN and the second peripheral detection pin a _ HP _ S; the peripheral detection triggering module 20 is configured to output a corresponding detection signal according to the level signals output by the first peripheral detection pin a _ HP _ IN and the second peripheral detection pin a _ HP _ S;

and the audio output control module 30 is configured to determine the type of the external device according to the detection signal output by the peripheral detection trigger module 20, and output an audio signal corresponding to the external device.

In this embodiment, the Audio jack 10 may adopt an 8-pin Mini type Audio jack 10 and the like to simultaneously support output in an Audio (analog) format, and may support output in an SPDIF (digital) Audio format. The audio jack 10 includes an audio jack 11 (not shown), a left channel pin a _ HP _ L, a right channel pin a _ HP _ R, a first peripheral detection pin a _ HP _ IN, a second peripheral detection pin a _ HP _ S, a digital audio output pin a _ SPDIF _ OUT, and a ground pin GND disposed IN the audio jack 11.

Specifically, the ground pin GND has elasticity, and when the external device is inserted into the audio jack 11, the ground pin GND is pushed by the external device and abuts against the first peripheral detection pin a _ HP _ IN; when the external device is pulled out of the audio jack 11, the grounding pin GND is elastically restored and separated from the first peripheral detection pin a _ HP _ IN. A pull-up resistor R6 is externally connected to the first peripheral detection pin a _ HP _ IN, and is connected to a first dc power supply VCC1 through a pull-up resistor R6. When the ground pin GND and the first peripheral detection pin a _ HP _ IN are separated from each other, the signal on the first peripheral detection pin a _ HP _ IN is pulled high by the pull-up resistor, so the level is high. When the ground pin GND and the first peripheral detection pin a _ HP _ IN are IN contact with each other, the signal on the first peripheral detection pin a _ HP _ IN is pulled low by the level of the ground pin GND, and therefore the level is low.

It should be noted that, because the earphones, the sound boxes and the like belong to general parts, the common heads of the earphones and the sound boxes are a four-segment earphone and a three-segment TRS according to the international standard citia standard, and the four-segment earphone (corresponding to the audio jack 10 from inside to outside) according to the international standard citia standard is a left sound channel, a right sound channel, a ground and a microphone from top to bottom in sequence. The three-section TRS headphone is sequentially a left channel, a right channel, and a ground from top to bottom (corresponding to the audio jack 10 from inside to outside). The present embodiment will be described by taking the audio jack 10 corresponding to a three-segment type earphone as an example. IN addition, the first peripheral detection pin a _ HP _ IN of the existing audio jack 10 can be used for detecting the plugging and unplugging of external devices such as earphones: the first peripheral detection pin A _ HP _ IN is adjacent to the grounding pin GND of the audio socket 10, when the earphone is inserted, the male head of the external equipment can drive the grounding pin GND to move and abut against the first peripheral detection pin A _ HP _ IN, therefore, when the external equipment is detected not to be inserted into or pulled out of the audio socket 10, the level of the first peripheral detection pin A _ HP _ IN is pulled high, and when the male head of the external equipment is detected to be inserted, the level of the first peripheral detection pin A _ HP _ IN can be overturned, and therefore the insertion or pulling-out detection of the external equipment can be achieved.

IN an embodiment, the ground pin GND has elasticity, and when a male plug of an external device is inserted into the audio jack 11, the ground pin GND is pushed by the male plug of the external device and abuts against the first peripheral detection pin a _ HP _ IN; when the male plug of the external equipment is pulled out of the audio jack 11, the grounding pin GND is elastically restored and is separated from the detection pin of the audio socket 10;

the second external detection pin A _ HP _ S is electrically connected with the grounding pin GND through a male head of the external equipment when the external equipment is analog audio equipment; and when the external equipment is digital audio equipment, the external equipment is in insulation connection with the grounding pin GND through the male head of the external equipment.

According to different requirements, the male head of the external device is insulated or conductive at the upper part (such as the area a shown in fig. 4) of the male head, specifically, the area a of the male head of the analog audio device is conductive, and the area a of the digital audio device is insulated. The second external detection pin a _ HP _ S of the audio jack 10 is physically connected through the a region. When the analog audio equipment is inserted, the electrical connection between the grounding pin GND and the second external detection pin A _ HP _ S is realized through the area A, and when the digital audio equipment is inserted, the insulation connection between the grounding pin GND and the second external detection pin A _ HP _ S is realized through the area A.

The second external detection pin a _ HP _ S is externally connected with a pull-up resistor, and is connected with a first direct current power supply VCC1 through the pull-up resistor R7. When the external equipment is inserted, if the external equipment is inserted into the external equipment, the second external detection pin A _ HP _ S is electrically connected with the ground pin GND through the male connector of the external equipment, and the signal on the second external detection pin A _ HP _ S is pulled down by the level of the ground pin GND, so that the level is low. If a digital audio device is inserted, the signal on the second peripheral detection pin a _ HP _ S is pulled high by the pull-up resistor, and thus the level is high.

IN summary, referring to table 1, the specific table below shows that whether the device is connected and what type of external device is connected can be known according to the high and low levels of the first peripheral detection pin a _ HP _ IN and the second peripheral detection pin a _ HP _ S.

TABLE 1

	First peripheral detection pin level	Second peripheral detection pin level
			No peripheral access	Height of	Height of
Analog audio peripheral access	Is low in	Is low in
			Digital audio peripheral access	Is low in	Height of

Two detection terminals of the peripheral detection trigger module 20 are connected to the first peripheral detection pin a _ HP _ IN and the second peripheral detection pin a _ HP _ S of the audio jack 10, and an output terminal of the peripheral detection trigger module 2020 is connected to a signal feedback terminal of the audio output control module 30. The peripheral detection triggering module 20 determines whether the audio jack 10 has an external device access according to the level change of the first peripheral detection pin a _ HP _ IN and the second peripheral detection pin a _ HP _ S, determines the type of the access external device when the device has an access, and outputs a corresponding detection signal. That is, when the signals output by the first peripheral detection pin a _ HP _ IN and the second peripheral detection pin a _ HP _ S are both low level, the peripheral detection trigger module 20 outputs an analog detection signal; and outputting a digital detection signal when the signal output by the first peripheral detection pin A _ HP _ IN is at a low level and the signal output by the second peripheral detection pin A _ HP _ S is at a high level.

In an embodiment, the audio jack 11 is further provided with a left channel pin a _ HP _ L, a right channel pin a _ HP _ R, and a digital audio output pin a _ SPDIF _ OUT; the audio output control module 30 is specifically configured to, when receiving the analog detection signal, convert an accessed digital audio signal into an analog audio signal and output the analog audio signal through the left channel pin a _ HP _ L and the right channel pin a _ HP _ R; and when receiving the digital detection signal, outputting the accessed digital audio signal through a digital audio output pin A _ SPDIF _ OUT.

The audio output control module 30 is integrated with a D/a conversion module, a decoder, and the like, and converts an accessed digital audio signal into an analog audio signal and outputs the analog audio signal when it is determined that the accessed external device is an analog audio device according to a detection signal output by the peripheral detection trigger module 20, so as to complete decoding and conversion of the audio signal and realize playing of the audio signal. When the accessed external device is determined to be the digital audio device, the accessed digital audio signal is directly output to the audio socket 10 without D/a conversion. By such arrangement, electromagnetic waves with serious interference in the case can be reduced, and the tone quality can be purified.

The audio output circuit of the invention realizes mutual butting of the grounding pin GND and the first external detection pin A _ HP _ IN by arranging the audio socket 10 and utilizing the grounding pin GND IN the audio jack 11 when the male plug of the external equipment is inserted into the audio jack 11, and realizes physical connection of the grounding pin GND and the second external detection pin A _ HP _ S by the male plug of the external equipment. And a peripheral detection triggering module 20 is provided to detect the level changes of the first peripheral detection pin a _ HP _ IN and the second peripheral detection pin a _ HP _ S provided IN the audio jack 10. That is, whether the external device is connected to the audio jack 10 is determined according to whether the second external detection pin a _ HP _ S is electrically connected to the ground pin GND. And when equipment is accessed, determining the type of the accessed external equipment, and outputting corresponding detection signals so as to select audio signals of corresponding modes to output according to different types of external equipment. The audio output circuit can output digital audio signals and analog audio signals, is compatible with different audio equipment and outputs audio signals corresponding to external equipment. The invention solves the problem that the electronic equipment can only be adapted to one external device and can not realize the compatibility of the digital sound box and the analog sound box.

Referring to fig. 2, IN an embodiment, the peripheral detection trigger module 20 includes a NAND logic gate NAND1 and an OR logic gate OR1, a first input terminal of the NAND logic gate NAND1 is connected to the first peripheral detection pin a _ HP _ IN, a second input terminal of the NAND logic gate NAND1 is connected to the second peripheral detection pin a _ HP _ S, and an output terminal of the NAND logic gate NAND1 is connected to the first signal feedback terminal of the audio output control module 30;

a first input terminal of the OR logic gate OR1 is connected to the first peripheral detection pin a _ HP _ IN, a second input terminal of the OR logic gate OR1 is connected to the second peripheral detection pin a _ HP _ S, and an output terminal of the OR logic gate OR1 is connected to the second signal feedback terminal of the audio output control module 30.

IN this embodiment, two input terminals of the NAND logic gate NAND1 are respectively connected to the first peripheral detection pin a _ HP _ IN and the second peripheral detection pin a _ HP _ S; two input terminals of the OR logic gate OR1 are respectively connected to the first peripheral detection pin a _ HP _ IN and the second peripheral detection pin a _ HP _ S. When the level of the first peripheral detection pin a _ HP _ IN is high and the level of the second peripheral detection pin a _ HP _ S is high, the NAND gate NAND1 outputs a low level signal, OR the OR gate OR1 outputs a low level signal, which indicates that no external device is connected. When the level of the first peripheral detection pin a _ HP _ IN is low and the level of the second peripheral detection pin a _ HP _ S is high, the NAND gate NAND1 outputs a high level signal, OR the OR gate OR1 outputs a low level signal, which indicates that the connected external device is a digital audio device. When the level of the first peripheral detection pin a _ HP _ IN is low and the level of the second peripheral detection pin a _ HP _ S is low, the NAND gate NAND1 outputs a high level signal, OR the OR gate OR1 outputs a low level signal, which indicates that the connected external device is a digital audio device.

Referring to fig. 2, in an embodiment, the peripheral detection trigger module 20 further includes a first signal indication circuit (not shown), and a controlled terminal of the first signal indication circuit is connected to an output terminal of the NAND gate NAND 1; wherein the content of the first and second substances,

the first signal indicating circuit comprises a first switch tube Q1, a first pull-up resistor R1, a second pull-up resistor R2 and a first LED lamp LED1, wherein a controlled end of the first switch tube Q1 is a controlled end of the first signal indicating circuit, an output end of the first switch tube Q1 is interconnected with a cathode of the first LED lamp LED1 and a first end of the first pull-up resistor R1, the first signal indicating circuit is connected with a first direct current power supply VCC1 through the first pull-up resistor R1, and an input end of the first switch tube Q1 is grounded; a second end of the first pull-up resistor R1 is connected with a first direct current power supply VCC 1; the anode of the first LED1 is connected to the first dc power VCC1 via the second pull-up resistor R2.

In this embodiment, the first switch Q1 may be implemented by using a triode, and the first switch Q1 is controlled by the NAND logic gate NAND1, and when the NAND logic gate NAND1 outputs a high level, the first switch Q1 is turned on, and the cathode of the first LED lamp LED1 is grounded, so as to trigger the first LED lamp LED1 to be turned on. When the NAND logic gate NAND1 outputs a low level, the first switch Q1 is turned off, and the cathode of the first LED lamp LED1 is pulled high by the first pull-up resistor R1, thereby triggering the first LED lamp LED1 to be turned off. Through setting up first signal indicator, can also make the user know external device whether insert successfully to and know what kind of external device that inserts.

Referring to fig. 2, in an embodiment, the peripheral detection trigger module 20 further includes a second signal indication circuit (not shown), and a controlled terminal of the second signal indication circuit is connected to the OR logic gate OR 1; wherein the content of the first and second substances,

the second signal indicating circuit comprises a second switching tube Q2, a third pull-up resistor R3 and a second LED lamp LED2, the controlled end of the second switching tube Q2 is the controlled end of the second signal indicating circuit, the input end of the second switching tube Q2 is grounded, and the output end of the second switching tube Q2 is connected with the anode of the second LED lamp LED2 through the third pull-up resistor R3; the cathode of the second LED light LED2 is grounded.

In this embodiment, the second switch Q2 may be implemented by a triode, and the second switch Q2 is controlled by the OR logic gate OR1, so that when the OR logic gate OR1 outputs a high level, the second switch Q2 is turned on, and the anode of the first LED lamp LED1 is grounded through the second pull-up resistor R2, thereby triggering the second LED lamp LED2 to be turned off. When the OR logic gate OR1 outputs a low level, the second switch Q2 is turned off, and the anode of the second LED lamp LED2 is pulled high by the third pull-up resistor R3, thereby triggering the second LED lamp LED2 to be turned on. Through setting up second signal indicator, can also make the user know external device whether insert successfully to and know what kind of external device that inserts.

Referring to fig. 2 and 3, in an embodiment, the audio output circuit further includes a digital audio signal output circuit 50, the digital audio signal output circuit includes a first voltage-dividing resistor R4, a second voltage-dividing resistor R5, and a transmitting module 12 integrated in the audio jack 11, a first end of the first voltage-dividing resistor R4 is connected to an output end of the audio output control module 30, a second end of the first voltage-dividing resistor R4 is connected to ground through the second voltage-dividing resistor R5, and a common end of the first voltage-dividing resistor R4 and the second voltage-dividing resistor R5 is connected to a digital audio output pin a _ SPDIF _ OUT integrated in the audio jack 11.

In this embodiment, when the digital audio output pin a _ SPDIF _ OUT (SPDIF signal output pin) detects that a digital audio device is accessed, the transmitting module 12 (infrared transmitting module 12) of the digital audio signal output circuit 50 operates, that is, it is said that an optical fiber signal is output at this time, and transmission of the digital audio signal is completed. Wherein, the first voltage dividing resistor R4 and the second voltage dividing resistor R5 are connected in series to divide the voltage to control the output of the digital audio signal. In this embodiment, the first voltage-dividing resistor R4 and the second voltage-dividing resistor R5 are preferably implemented by adjustable resistors, so as to realize adjustable output size of the digital audio signal, thereby improving the sensitivity of the audio output circuit. Further, the digital audio output circuit further includes a power supply pull-up resistor and a power supply capacitor C1, and the capacitor C1 is used for filtering noise in the first dc power supply VCC 1.

Referring to fig. 2 and 3, based on the above embodiment, the audio output circuit further includes a power switch circuit, a controlled terminal of the power switch circuit is connected to the output terminal of the first signal indicating circuit, an input terminal of the power switch circuit is connected to the first dc power VCC1, and an output terminal of the power switch circuit is connected to the power terminal of the transmitting module 12.

In this embodiment, the power switch circuit includes a third switch tube Q3, a controlled terminal of the third switch tube Q3 is connected to output terminals of the first pull-up resistor R1 and the first switch tube Q1, respectively, an input terminal of the third switch tube Q3 is connected to the first direct current power VCC1, and an output terminal of the third switch tube Q3 is connected to a power supply terminal of the transmitting module 12. When the first switch Q1 is turned on, the third switch Q3 is turned on at the same time, i.e. the output terminal has a high voltage output, which is used to supply power to the interior of the transmission module 12(SPDIF module) of the digital audio device. In other embodiments, of course, according to the requirement of practical application, when the user selects to access only the digital audio device or only the analog audio device, the digital audio output pin a _ SPDIF _ OUT may be shorted when only the analog audio device is accessed, and at this time, the power switch circuit may not be needed. When only the digital audio device is accessed, the output pin of the analog audio signal can be short-circuited.

Referring to fig. 1 to fig. 3, based on the above embodiment, the audio output circuit further includes a further audio processing module 40, the audio socket 10 further includes a left channel pin a _ HP _ L and a right channel pin a _ HP _ R, an input end of the audio processing module 40 is connected to the audio output control module 30, a left channel audio signal output end of the audio processing module 40 is connected to the left channel pin a _ HP _ L of the audio socket 10, and a right channel audio signal output end of the audio processing module 40 is connected to the right channel pin a _ HP _ R of the audio socket 10.

In this embodiment, the audio processing module 40 is configured to output the audio signal to the audio jack 10 and the speaker based on the control of the main control module 30 after processing the audio signal.

Further, the audio processing module 40 includes an operational amplifier IC, such as a DRV632 operational amplifier, and the operational amplifier IC is configured to amplify the audio signal and output the amplified audio signal. Of course, in other embodiments, the audio processing module 40 can also be implemented by the audio output control module 30 under the condition that the audio output control module 30, such as a sound card, has a very strong driving capability, which is not limited herein.

Referring to fig. 2 and 3, the left channel pin a _ HP _ L, the right channel pin a _ HP _ R, the digital audio output pin a _ SPDIF _ OUT, the first peripheral detection pin a _ HP _ IN, and the second peripheral detection pin a _ HP _ S are further provided with esd protection diodes D1-D4 for absorbing static electricity on the left channel pin a _ HP _ L and the right channel pin a _ HP _ R. When the circuit works normally, the electrostatic protection diodes D1-D4 are in a high-impedance state, and the normal operation of the circuit cannot be influenced. When abnormal overvoltage occurs IN the circuit and the breakdown voltage is reached, the electrostatic protection diodes D1-D4 are changed from a high-impedance state to a low-impedance state, a low-impedance conduction path is provided for transient current, and the voltage input from the left channel pin A _ HP _ L, the right channel pin A _ HP _ R, the digital audio output pin A _ SPDIF _ OUT, the first external detection pin A _ HP _ IN and the second external detection pin A _ HP _ S is clamped IN a safe range, so that the audio output circuit and the external equipment are prevented from being damaged by the excessive voltage. When the abnormal overvoltage disappears, the electrostatic protection diodes D1-D4 restore to a high-resistance state, and the circuit operates normally. The left channel pin A _ HP _ L and the right channel pin A _ HP _ R are further provided with filter inductors L11 and L12 and filter capacitors C11 and C12, noise signals on the left channel pin A _ HP _ L and the right channel pin A _ HP _ R are filtered, and therefore the quality of audio signals on the left channel pin A _ HP _ L and the right channel pin A _ HP _ R is improved.

The invention also provides an electronic device which comprises a video system and the audio output circuit. The specific structure of the audio output circuit refers to the above embodiments, and since the electronic device adopts all technical solutions of all embodiments of the audio output circuit, all beneficial effects brought by the technical solutions of at least the above embodiments of the audio output circuit are achieved, and are not described in detail herein.

In this embodiment, the electronic device may be an electronic device such as an android television, a laptop, a mobile phone, and the like, which is not limited herein.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. An audio output circuit, the audio output circuit comprising:

the grounding pin and the first peripheral detection pin are mutually abutted when a male head of an external device is inserted into the audio jack; the grounding pin is also physically connected with the second external detection pin through a male head of an external device; the second external detection pin is electrically connected with the grounding pin through a male head of the external equipment when the external equipment is analog audio equipment; when the external equipment is digital audio equipment, the external equipment is in insulated connection with the grounding pin through a male head of the external equipment;

the detection end of the peripheral detection trigger module is respectively connected with the first peripheral detection pin and the second peripheral detection pin; the peripheral detection trigger module is used for outputting corresponding detection signals according to level signals output by the first peripheral detection pin and the second peripheral detection pin;

2. The audio output circuit of claim 1, wherein the grounding pin is resilient and is pushed by a male plug of an external device to abut against the first peripheral detection pin when the male plug of the external device is inserted into the audio jack; when the male connector of the external equipment is pulled out of the audio jack, the grounding pin is elastically restored and separated from the audio socket detection pin.

3. The audio output circuit of claim 2, wherein the peripheral detection trigger module outputs an analog detection signal when the signals output by the first peripheral detection pin and the second peripheral detection pin are both low;

4. The audio output circuit of claim 3, wherein a left channel pin, a right channel pin, and a digital audio output pin are further disposed within the audio jack;

5. The audio output circuit according to any of claims 1 to 4, wherein the peripheral detection trigger module comprises a NAND logic gate and an OR logic gate, a first input terminal of the NAND logic gate is connected to the first peripheral detection pin, a second input terminal of the NAND logic gate is connected to the second peripheral detection pin, and an output terminal of the NAND logic gate is connected to the first signal feedback terminal of the audio output control module;

6. The audio output circuit of claim 5, wherein the peripheral detection trigger module further comprises a first signal indication circuit, a controlled terminal of the first signal indication circuit being connected to the output terminal of the NAND logic gate; wherein the content of the first and second substances,

7. The audio output circuit of claim 5, wherein the peripheral detection trigger module further comprises a second signal indication circuit, a controlled terminal of the second signal indication circuit being connected to the OR logic gate; wherein the content of the first and second substances,

8. The audio output circuit of claim 6, further comprising a digital audio signal output circuit, wherein the digital audio signal output circuit comprises a first voltage-dividing resistor, a second voltage-dividing resistor, and a transmitter module integrated in the audio jack, a first end of the first voltage-dividing resistor is connected to an output terminal of the audio output control module, a second end of the first voltage-dividing resistor is connected to ground via the second voltage-dividing resistor, and a common terminal of the first voltage-dividing resistor and the second voltage-dividing resistor is connected to a digital audio output pin integrated in the audio jack.

9. The audio output circuit of claim 8, further comprising a power switch circuit, wherein the controlled terminal of the power switch circuit is connected to the output terminal of the first signal indication circuit, the input terminal of the power switch circuit is connected to the first direct current power supply, and the output terminal of the power switch circuit is connected to the power terminal of the transmitter module.

10. An electronic device, characterized in that the electronic device comprises an audio output circuit according to any of claims 1 to 9.