CN113676572A

CN113676572A - Interface circuit and electronic device

Info

Publication number: CN113676572A
Application number: CN202110889761.7A
Authority: CN
Inventors: 陈澜轩; 龚夏杰; 李伏海
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2021-08-04
Filing date: 2021-08-04
Publication date: 2021-11-19
Anticipated expiration: 2041-08-04
Also published as: CN113676572B

Abstract

The application discloses interface circuit and electronic equipment, wherein interface circuit includes: an earphone interface; the audio module is connected with the earphone interface through the adaptation module; the electronic equipment comprises a frequency modulation module and a change-over switch, wherein the frequency modulation module is connected with the earphone interface through the change-over switch, when the electronic equipment is in a frequency modulation mode, the change-over switch is switched on, and the frequency modulation module receives FM signals through an earphone connected with the earphone interface. In this application, the frequency modulation module sets up before the adaptation module, and the frequency modulation module passes through change over switch and earphone interface electricity to be connected, and like this, the transmission of FM signal need not pass through the adaptation module, and the adaptation module also can not cause the interference to the FM signal to can improve FM signal quality.

Description

Interface circuit and electronic device

Technical Field

The application belongs to the technical field of electronic equipment, and particularly relates to an interface circuit and electronic equipment.

Background

Electronic devices are typically configured with a headset interface for connecting a headset. In order to make the interface circuit of the earphone interface have an audio transmission function, an audio module and an adaptation module are usually arranged in the interface circuit, and the audio module is connected with the earphone interface through the adaptation module. FM (frequency modulation radio) is a common function of electronic equipment, the frequency of FM is low (70MHz to 120MHz), and earphone wires can be multiplexed into a receiving antenna of FM. Currently, the FM module of the electronic device is generally electrically connected to the earphone interface through the adapter module. However, this causes a large disturbance to the FM signal due to the large power supply noise present in the adaptation module.

Disclosure of Invention

The application aims to provide an interface circuit and electronic equipment, and at least solves the problem that FM signals are greatly interfered due to the fact that the adapter module has large power supply noise.

In order to solve the technical problem, the present application is implemented as follows:

in a first aspect, an embodiment of the present application provides an interface circuit, which is applied to an electronic device, and includes:

an earphone interface;

the audio module is connected with the earphone interface through the adaptation module;

the electronic equipment comprises a frequency modulation module and a change-over switch, wherein the frequency modulation module is connected with the earphone interface through the change-over switch, when the electronic equipment is in a frequency modulation mode, the change-over switch is switched on, and the frequency modulation module receives FM signals through an earphone connected with the earphone interface.

In a second aspect, an embodiment of the present application provides an electronic device, including the interface circuit described in the first aspect.

In the embodiment of this application, the frequency modulation module sets up before the adaptation module, and the frequency modulation module no longer is connected with the earphone interface electricity through the adaptation module, but is connected with the earphone interface electricity through change over switch, and like this, the transmission of FM signal no longer passes through the adaptation module, and the adaptation module also can not cause the interference to the FM signal to can improve FM signal quality.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of an interface circuit provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a forward and backward insertion identification module according to an embodiment of the present application.

Reference numerals:

10. an earphone interface; 20. an adaptation module; 30. an audio module; 40. a switch; 50. a frequency modulation module; 60. a control module;

11. a ground pin; 12. an MIC pin; 13. a forward and reverse insertion identification module; 31. a ground terminal; 32. an MIC end; 41. a first contact; 42. a second contact; 21. a first input terminal; 22. a second input terminal; 23. a first output terminal; 24. a second output terminal; SBU1, a first signal line; SBU2, a first signal line; GND, a third signal line; MIC, fourth signal line; FM, fifth signal line;

131. a voltage comparator; 1311. a first input pole; 1312. a second input pole; 1313. an output electrode; r1, a first resistor; r2, a second resistor; r3, third resistor; r4, fourth resistor; r5, fifth resistor; VCC, a first voltage terminal; A. a first contact; B. a second contact.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application. 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 application.

The features of the terms first and second in the description and in the claims of the present application may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specified. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

In the description of the present application, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

As shown in fig. 1, an interface circuit according to an embodiment of the present disclosure includes an earphone interface 10, an adaptation module 20, an audio module 30, a switch 40, and a frequency modulation module 50. The audio module 30 is connected to the earphone interface 10 through the adaptation module 20, and the fm module 50 is connected to the earphone interface 10 through the switch 40. When the electronic device is in the FM mode, the switch 40 is turned on, and the FM module 50 receives FM signals through the earphone connected to the earphone interface 10.

The form of the headphone interface 10 is not limited, for example: a 3.5mm earphone interface, a charging and earphone integrated interface (such as a TYPE-C interface), and the like.

The adaptation module 20 has one end connected to the audio module 30 and the other end connected to the earphone interface. One end of the switch 40 is connected to the fm module 50, and the other end is connected to the earphone interface 10. That is, the fm module 50 is disposed before the adaptor module 20, that is, the fm module 50 is connected to the earphone interface 10 at the input side (or front side) of the adaptor module 20.

Generally, the adaptation module 20 is a high-speed chip, and has a large power supply noise, which is easy to introduce power supply noise. In the embodiment of the present application, since the FM module 50 is disposed before the adaptor module 20, the FM module 50 is not electrically connected to the earphone interface 10 through the adaptor module 20, but is electrically connected to the earphone interface 10 through the switch 40, so that the FM signal does not pass through the adaptor module 20. Therefore, on one hand, the interference of power supply noise introduced by the adaptation module 20 on the FM signal can be avoided, and the quality of the FM signal can be improved; on the other hand, the line length of FM signal transmission can be shortened, and the insertion loss of the FM signal transmission in the bandwidth can be effectively reduced.

In some embodiments, the headset interface 10 is provided with a ground pin 11 and an MIC pin 12;

the first end of the switch 40 is electrically connected to the fm module 50, the second end has a first contact 41 and a second contact 42, the first contact 41 is connected to the ground pin 11 through a first signal line SBU1, and the second contact 42 is connected to the MIC pin 12 through a second signal line SBU 2.

In some embodiments, the first end of the switch 40 is in communication with the first contact 41 when the earphone is connected to the earphone interface 10 in the first connection state, and the first end of the switch 40 is in communication with the second contact 42 when the earphone is connected to the earphone interface 10 in the second connection state, so that the FM signal is received by the FM module 50 through the ground line of the earphone.

In this way, by providing the changeover switch 40, the FM module 50 can receive FM signals through the ground line of the earphone, regardless of whether the earphone is connected to the earphone interface 10 in the first connection state or the second connection state.

In some embodiments, the earphone interface 10 is a TYPE-C interface, and the earphone interface 10 is provided with a ground pin 11, an MIC pin 12, and a positive and negative insertion identification module 13. The TYPE-C interface can be used for inserting a TYPE-C earphone, and the TYPE-C interface can also be provided with a left sound track pin and a right sound track pin (or a D + pin and a D-pin). When detecting that the TYPE-C earphone is inserted into the TYPE-C interface, the forward and reverse insertion identification module 13 may identify whether the TYPE-C earphone is being inserted or being reversely inserted.

When the forward and reverse insertion recognition module 13 recognizes that the earphone is inserted into the earphone interface 10 in the forward direction, the first end of the switch 40 is communicated with the first contact 41, and when the forward and reverse insertion recognition module 13 recognizes that the earphone is inserted into the earphone interface 10 in the reverse direction, the first end of the switch 40 is communicated with the second contact 42.

Here, the first end of the switch 40 is electrically connected to the fm module 50, the second end thereof is electrically connected to the first signal line SBU1 and the second signal line SBU2, and the switch 40 is also electrically connected to the positive and negative insertion recognition module 13. The switch 40 and the FM module 50 may be connected via a fifth signal line FM. The switch 40 can adjust the connection state of the switch 40 according to the recognition result of the positive and negative insertion recognition module 13.

By providing the changeover switch 40 in this way, the FM signal can be received by the FM module 50 through the ground line of the headphone regardless of whether the headphone is inserted into the headphone interface 10 in the forward direction or in the reverse direction.

In some embodiments, the audio module 30 includes a ground terminal 31 and a MIC terminal 32.

The adaptor module 20 includes a first input terminal 21, a second input terminal 22, a first output terminal 23, and a second output terminal 24, where the first input terminal 21 is electrically connected to the ground pin 11 through a first signal line SBU1, the second input terminal 22 is electrically connected to the MIC pin 12 through a second signal line SBU2, the first output terminal 23 is electrically connected to the ground terminal 31 through a third signal line GND, and the second output terminal 24 is electrically connected to the MIC terminal 32 through a fourth signal line MIC. The adaptation module 20 can adjust the communication state of each input end and each output end according to the recognition result of the forward and backward interpolation recognition module 13.

When the recognition result of the positive and negative insertion recognition module 13 is positive insertion, the first input terminal 21 is communicated with the first output terminal 23, the second input terminal 22 is communicated with the second output terminal 24, and the switch 40 is communicated with the first signal line SBU1, when the recognition result of the positive and negative insertion recognition module 13 is negative insertion, the first input terminal 21 is communicated with the second output terminal 24, the second input terminal 22 is communicated with the first output terminal 23, and the switch 40 is communicated with the second signal line SBU 2.

The switching logic of the switch 40 is as follows: when the TYPE-C earphone is being inserted, the first signal line SBU1 communicates with the third signal line GND, and the second signal line SBU2 communicates with the fourth signal line MIC. At this time, the changeover switch 40 can be switched to communicate with the first signal line SBU1, so that the paths of the first signal line SBU1 and the third signal line GND can be used as the FM antenna. When the TYPE-C earphone is reversely plugged, the first signal line SBU1 and the third signal line GND are connected, and the second signal line SBU2 and the fourth signal line MIC are connected, and the first signal line SBU1 and the fourth signal line MIC are connected, and the second signal line SBU2 and the third signal line GND are connected. At this time, the changeover switch 40 can be switched to communicate with the second signal line SBU2, so that the passage of the second signal line SBU2 and the third signal line GND can be used as the FM antenna.

In this way, in both the forward insertion state and the reverse insertion state, the passage in which the third signal line GND is located can be used as the FM antenna, that is, the ground can be used as the FM antenna. Compared with the mode that the left and right sound channel signal lines are used as the FM antenna, the mode that the ground line is used as the FM antenna has the following advantages that: the FM signal and the audio left and right channels do not need to be coupled together, and when elements such as capacitors need to be arranged on the audio left and right channels, the performance of the FM signal cannot be interfered.

In some embodiments, as shown in fig. 1, the interface circuit further includes a control module 60, the control module 60 is electrically connected to the forward/reverse insertion identification module 13 and the switch 40, respectively, and the control module 60 controls the first end of the switch 40 to communicate with the first contact 41 or the second contact 42 according to the identification result of the forward/reverse insertion identification module 13.

Illustratively, the positive and negative insertion identification module 13 may include a variable resistor, and the resistance of the TYPE-C interface may vary when the TYPE-C earphone is inserted positively or negatively. In this way, the control module 60 can recognize the positive and negative insertion states by recognizing the resistance change, so as to control the operating state of the switch 40 to ensure that the FM normally operates.

In some embodiments, as shown in fig. 2, the positive and negative insertion identification module 13 includes:

the voltage comparator 131 comprises a first input pole 1311, a second input pole 1312 and an output pole 1313, wherein one pole of the first input pole 1311 and the second input pole 1312 is a positive pole, the other pole of the first input pole 1311 and the second input pole 1312 is a negative pole, and the output pole 1313 is electrically connected with the control module 60;

a first resistor R1, one end of which is electrically connected to the first voltage terminal VCC and the other end of which is electrically connected to the first input electrode 1311;

a second resistor R2 having one end grounded and the other end electrically connected to the first input electrode 1311;

a third resistor R3, one end of which is electrically connected to the first voltage terminal VCC and the other end of which is electrically connected to the second input electrode 1312;

a fourth resistor R4, one end of which is electrically connected to the first contact a of the TYPE-C interface and the other end of which is electrically connected to the second input electrode 1312;

a fifth resistor R5, one end of which is electrically connected to the second contact B of the TYPE-C interface and the other end of which is electrically connected to the second input electrode 1312,

the control module 60 controls the switch 40 to connect the first signal line SBU1 or the second signal line SBU2 according to the output level of the output electrode 1313.

Illustratively, the first input terminal 1311 is a positive terminal, the second input terminal 1312 is a negative terminal, and the voltage comparator 131 is configured to output a high level when the positive terminal voltage is greater than the negative terminal voltage, and output a low level otherwise.

One of the first contact a and the second contact B of the TYPE-C interface is open and one is short (i.e., grounded). Assuming that the first contact a is open and the second contact B is short-circuited during the positive insertion, the voltage of the first voltage terminal VCC flows through the third resistor R3 and the fifth resistor R5, and the voltage of the negative electrode is V ═ VCC R5/(R3+ R5). When the plug is inserted reversely, the first contact a is short-circuited, the second contact B is open-circuited, the voltage of the first voltage terminal VCC flows through the third resistor R3 and the fourth resistor R4, and the voltage of the negative electrode is V-' (VCC R4/(R3+ R5). The values of R1 and R2 can be set, a reference voltage V + is provided at the positive electrode, and the resistance values of R1 to R5 are reasonably designed to satisfy V- < V + < V-', so that a high level is output when the positive plug is inserted, and a low level is output when the negative plug is inserted, thereby realizing that the control module 60 controls the switch 40 to communicate with the first signal line SBU1 or the second signal line SBU2 according to the output level of the output electrode 1313.

It should be noted that the positive and negative insertion identification module 13 may also adopt other circuit structures, which is not limited in this application.

In some embodiments, the wire diameter of the third signal wire GND is larger than that of the fourth signal wire MIC.

Since the path in which the third signal line GND is located is used as the FM antenna in both the forward insertion state and the reverse insertion state, the loss of the FM signal can be reduced by increasing the wire diameter of the third signal line GND in this embodiment.

In some embodiments, the wire diameter of the first signal wire SBU1 is equal to the wire diameter of the second signal wire SBU 2.

In the forward insertion state, the first signal line SBU1 serves as a transmission line for FM signals, and in the reverse insertion state, the second signal line SBU2 serves as a transmission line for FM signals.

In some embodiments, the fourth signal line MIC is a ground-clad signal line.

Since the path in which the fourth signal line MIC is located is not used as a transmission path of the FM signal, the fourth signal line MIC may be subjected to a packet shielding process, and when the fourth signal line MIC operates, the MIC signal may be prevented from being interfered by other signals, for example, the FM signal.

An embodiment of the present application further provides an electronic device, including the interface circuit of any of the above embodiments.

In some embodiments, the switch 40 is disposed on a Flexible Printed Circuit (FPC), and the audio module 30, the adaptation module 20, and the fm module 50 are disposed on the motherboard.

In some embodiments, the interface circuit includes a control module 60, the control module 60 being electrically connected to the CPU of the electronic device.

Thus, the switching of the selector switch 40 can be realized by the CPU, so that the control is more centralized and the configurations of the interface circuit and the electronic device are simpler.

It should be noted that the implementation manner of the above interface circuit embodiment is also applicable to the embodiment of the electronic device, and can achieve the same technical effect, and details are not described herein again.

In the embodiment of the present application, the electronic device may be a mobile phone, a tablet computer, a notebook computer, a palm computer, a vehicle-mounted electronic device, a wearable device, an ultra-mobile personal computer (UMPC), a netbook, or a Personal Digital Assistant (PDA).

Other configurations and operations of the electronic device according to the embodiments of the present application are known to those of ordinary skill in the art and will not be described in detail herein.

In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. An interface circuit applied to an electronic device, comprising:

an earphone interface;

2. The interface circuit of claim 1, wherein the headset interface is provided with a ground pin and a MIC pin;

the first end of the change-over switch is electrically connected with the frequency modulation module, the second end of the change-over switch is provided with a first contact and a second contact, the first contact is connected with the grounding pin through a first signal wire, and the second contact is connected with the MIC pin through a second signal wire.

3. The interface circuit of claim 2, wherein the first terminal of the switch is in communication with the first contact when the headset is interfaced with the headset in the first connected state and the second terminal of the switch is in communication with the second contact when the headset is interfaced with the headset in the second connected state, such that the FM module receives FM signals through the headset ground.

4. The interface circuit according to claim 3, wherein the earphone interface is a TYPE-C interface, and the earphone interface is further provided with a forward and backward insertion identification module;

when the forward and reverse insertion identification module identifies that the earphone is inserted into the earphone interface in the forward direction, the first end of the change-over switch is communicated with the first contact, and when the forward and reverse insertion identification module identifies that the earphone is inserted into the earphone interface in the reverse direction, the first end of the change-over switch is communicated with the second contact.

5. The interface circuit according to claim 4, further comprising a control module, wherein the control module is electrically connected to the forward and backward insertion identification module and the switch, respectively, and the control module controls the first end of the switch to communicate with the first contact or the second contact according to the identification result of the forward and backward insertion identification module.

6. The interface circuit of claim 5, wherein the positive and negative insertion identification module comprises:

the voltage comparator comprises a first input pole, a second input pole and an output pole, one pole of the first input pole and the second input pole is a positive pole, the other pole of the first input pole and the second input pole is a negative pole, and the output pole is electrically connected with the control module;

one end of the first resistor is electrically connected with the first voltage end, and the other end of the first resistor is electrically connected with the first input electrode;

one end of the second resistor is grounded, and the other end of the second resistor is electrically connected with the first input pole;

a third resistor, one end of which is electrically connected to the first voltage terminal and the other end of which is electrically connected to the second input terminal;

one end of the fourth resistor is electrically connected with the first contact of the earphone interface, and the other end of the fourth resistor is electrically connected with the second input electrode;

a fifth resistor, one end of which is electrically connected with the second contact of the earphone interface and the other end of which is electrically connected with the second input pole,

the control module controls the first end of the change-over switch to be communicated with the first contact or the second contact according to the output level of the output pole.

7. The interface circuit of claim 2, wherein the audio module comprises a ground terminal and a MIC terminal;

the adapter module comprises a first input end, a second input end, a first output end and a second output end, wherein the first input end is connected with the grounding pin through the first signal wire, the second input end is connected with the MIC pin through the second signal wire, the first output end is connected with the grounding end through the third signal wire, and the second output end is connected with the MIC end through the fourth signal wire.

8. An electronic device comprising the interface circuit of any one of claims 1 to 7.

9. The electronic device of claim 8, wherein the switch is disposed on a Flexible Printed Circuit (FPC), and the audio module, the adapter module and the frequency modulation module are disposed on a motherboard.

10. The electronic device of claim 8, wherein the interface circuit comprises a control module electrically connected to a CPU of the electronic device.