Audio switching circuit and terminal equipment

Abstract

The utility model discloses an audio switching circuit and terminal equipment, the circuit comprises a monaural sound card chip, a first switching unit, a second switching unit, a first audio playing unit and a second audio playing unit, one end of the monaural sound card chip is connected with an earphone, the other end of the monaural sound card chip is respectively connected with the first switching unit and the second switching unit, and the first audio playing unit is connected with the second audio playing unit. The first switching unit and the second switching unit are respectively connected with input and output signals of the first audio playing unit and the second audio playing unit, when an earphone is not inserted, the monaural sound card chip enables the first audio playing unit to work through the first switching unit and the second switching unit, and when the earphone is inserted, the monaural sound card chip enables the second audio playing unit to work through the second switching unit. The monaural sound card chip enables the second audio playing unit to work through the first switching unit and the second switching unit. According to the utility model, through the monaural sound card chip and the two switching units, free selection of multichannel audio output interfaces is realized, and the cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic equipment, in particular to a mono-channel to multi-channel audio switching circuit and terminal equipment. Background Art

[0002] Currently, a mono sound card is a sound card with only a single audio input and a single audio output channel. It is mainly used in simple application scenarios. At the same time, since a mono sound card does not have additional signal processors and speaker interfaces, the cost is relatively low. However, computers generally require several types of interface outputs such as headphone output, speaker output, and recording input. Due to the interface function limitations, a mono sound card cannot meet the requirements of the computer motherboard, so a multi-channel sound card must be configured to meet the needs of different customers. Utility Model Content

[0003] In view of the above technical problems, the utility model provides a mono-channel to multi-channel audio switching circuit and a terminal device.

[0004] One embodiment of the utility model provides an audio switching circuit, the circuit comprising a mono sound card chip, a first switching unit, a second switching unit, a first audio playback unit and a second audio playback unit, one end of the mono sound card chip is connected to a headset, and the other end is respectively connected to the first switching unit and the second switching unit, the first switching unit and the second switching unit are respectively connected to the input and output signals of the first audio playback unit and the second audio playback unit, when the headset is not inserted, the mono sound card chip enables the first audio playback unit to work through the first switching unit and the second switching unit, and when the headset is inserted, the mono sound card chip enables the second audio playback unit to work through the first switching unit and the second switching unit.

[0005] Optionally, the first audio playback unit includes a built-in microphone and / or a built-in speaker.

[0006] Optionally, the second audio playback unit includes an external headphone interface.

[0007] Optionally, the second audio playback unit includes a recording input connector for an external headset. When the headset is inserted, the mono sound card chip connects the external headset interface and the recording input connector for the external headset via the first switching unit and the second switching unit.

[0008] Optionally, the recording input connector is connected to a first switching unit.

[0009] Optionally, the second audio playback unit includes a two-in-one interface of an external headphone interface and a microphone input interface.

[0010] Optionally, the mono sound card chip adopts a CJC6811A chip.

[0011] Optionally, the circuit also includes a first signal processing circuit and a second signal processing circuit. When the earphone is not inserted, the mono sound card chip is at a high level, the mono sound card chip is connected to the second switching unit and the first switching unit, the second switching unit is connected to the built-in speaker through the second signal processing circuit, and the first switching unit is connected to the built-in microphone through the first signal processing circuit; when the earphone is inserted, the mono sound card chip is at a low level, the mono sound card chip is connected to the second switching unit and the first switching unit, the second switching unit is connected to the external headphone interface through the second signal processing circuit, and the first switching unit is connected to the recording input connector of the external headphone through the first signal processing circuit.

[0012] Optionally, the first signal processing circuit includes a magnetic bead, and the second signal processing circuit includes coupling capacitors CA55, CA56, current limiting resistors RA66, RA69 and audio power amplifiers UA5, UA6, one end of the coupling capacitor CA55 is connected to the second switching unit, and the other end is connected to one end of the current limiting resistor RA66, and the other end of the current limiting resistor RA66 is connected to the audio power amplifier UA5; one end of the capacitor CA56 is connected to the second switching unit, and the other end is connected to one end of the current limiting resistor RA69, and the other end of the current limiting resistor RA69 is connected to the audio power amplifier UA6.

[0013] Another embodiment of the present invention further provides a terminal device, wherein the terminal device includes an audio switching circuit as described in any one of the above items.

[0014] In the technical solution provided by the embodiment of the utility model, when the earphone is not inserted, the mono sound card chip is connected to the first audio playback unit through the first switching unit and the second switching unit to work; when the earphone is inserted, the mono sound card chip is connected to the second audio playback unit through the first switching unit and the second switching unit to work. Compared with the prior art, the advantage of the utility model is that, through the mono sound card chip and the two switching units, the multi-channel audio output interface can be freely selected, thereby saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The utility model is a circuit diagram of an audio switching circuit.

[0016] Figure 2 The utility model discloses a circuit diagram of a mono sound card chip in an audio switching circuit.

[0017] Figure 3 The utility model is a circuit diagram of a first switching unit in an audio switching circuit.

[0018] Figure 4 The utility model is a circuit diagram of a second switching unit in an audio switching circuit.

[0019] Figure 5 The utility model is a circuit diagram of a control module in an audio switching circuit.

[0020] Figure 6 The circuit diagram of the audio power amplifiers UA5 and UA6 in the utility model. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0022] It should be noted that when an element is described as being “connected” or “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0023] The utility model provides an audio switching circuit, please refer to Figure 1 As shown, the circuit includes a mono sound card chip, a first switching unit, a second switching unit, a first audio playback unit and a second audio playback unit. One end of the mono sound card chip is connected to an external headset, and the other end is respectively connected to the first switching unit and the second switching unit. The first switching unit and the second switching unit are respectively connected to the input and output signals of the first audio playback unit and the second audio playback unit. When the headset is not inserted, the mono sound card chip enables the first audio playback unit to work through the first switching unit and the second switching unit. When the headset is inserted, the mono sound card chip enables the second audio playback unit to work through the first switching unit and the second switching unit.

[0024] The utility model realizes free selection of multi-channel audio output interfaces through a monophonic sound card chip and two switching units, thereby saving costs.

[0025] In one embodiment of the present invention, the first audio playback unit includes a built-in microphone and / or a built-in speaker; the second audio playback unit includes an external headphone interface; in another embodiment of the present invention, the second audio playback unit includes a two-in-one interface of an external headphone interface and a microphone input interface.

[0026] In one embodiment of the present invention, the second audio playback unit further includes a recording input connector for an external headset, and when the headset is inserted, the mono sound card chip connects the external headset interface and the recording input connector for the external headset via the first switching unit and the second switching unit. The recording input connector is connected to the first switching unit.

[0027] Please refer to Figure 2-Figure 6 As shown, in one embodiment of the present utility model, the mono sound card chip adopts CJC6811A chip. The first switching unit U3 adopts RS2057XC6 chip, the second switching unit UA adopts RS2000 chip. The audio power amplifiers UA5 and UA6 both adopt AW8010AFCR chip.

[0028] Specifically, when the earphone PHONE JACK1 is not inserted, the earphone socket detection pin HPOUT_JD_CON is low level, and this pin is connected to the 15PIN GPIO2 of the mono sound card chip UA1. At this time, the 15PIN GPIO2 of the mono sound card chip UA1 is controlled to be high level. By detecting the state of GPIO2 and controlling the 14PIN GPIO0 of the mono sound card chip UA1 to be high level and the 10PIN GPIO3 of the mono sound card chip UA1 to be low level, the common input end of the second switching unit UA4 is controlled to connect to the NO normally open channel, and the common input end of the first switching unit UA3 is controlled to connect to the NC normally closed channel. This is the default state, and the channel connections are respectively for the built-in speaker and the built-in speaker MIC function to be turned on.

[0029] When the earphone PHONE JACK1 is inserted, the earphone socket detection pin HPOUT_JD_CON is suspended, and the 15PIN GPIO2 of the mono sound card chip UA1 is controlled to be low level. By detecting the GPIO2 state and controlling the 14PIN GPIO0 of the mono sound card chip UA1 to be low level and the 10PIN GPIO3 of the mono sound card chip UA1 to be high level, the common input end of the second switching unit UA4 is controlled to connect to the NC normally closed channel, and the common input end of the first switching unit UA3 is controlled to connect to the NO normally open channel. At this time, it is a special state of detecting the insertion of the earphone, and the channel connections are respectively external earphones and recording input connectors.

[0030] In one embodiment of the utility model, the circuit also includes a first signal processing circuit and a second signal processing circuit. When the earphone is not inserted, the mono sound card chip UA1 is at a high level, the mono sound card chip UA1 is connected to the second switching unit UA4 and the first switching unit UA3, the second switching unit UA4 is connected to the built-in speaker through the second signal processing circuit, and the first switching unit UA3 is connected to the built-in microphone through the first signal processing circuit; when the earphone is inserted, the mono sound card chip UA1 is at a low level, the mono sound card chip UA1 is connected to the second switching unit UA4 and the first switching unit UA3, the second switching unit UA4 is connected to the external earphone interface through the second signal processing circuit, and the first switching unit UA3 is connected to the recording input connector of the external earphone through the first signal processing circuit.

[0031] Please refer to Figure 6 As shown, the first signal processing circuit includes a magnetic bead, and the second signal processing circuit includes coupling capacitors CA55, CA56, current limiting resistors RA66, RA69 and audio power amplifiers UA5, UA6, one end of the coupling capacitor CA55 is connected to the second switching unit UA4, and the other end is connected to one end of the current limiting resistor RA66, and the other end of the current limiting resistor RA66 is connected to the audio power amplifier UA5; one end of the capacitor CA56 is connected to the second switching unit UA4, and the other end is connected to one end of the current limiting resistor RA69, and the other end of the current limiting resistor RA69 is connected to the audio power amplifier UA6.

[0032] Please refer to Figure 2-Figure 6 As shown, the specific implementation process of the utility model is as follows:

[0033] When the earphone is not plugged in, the GPIO2 of the mono sound card chip UA1 is detected as high level, and GPIO0 is controlled to be high level and GPIO3 is low level. The left and right channel audio signals HP_L and HP_R outputted from the 25th and 27th pins of the mono sound card chip UA1 are connected to the common input end of the 4th pin of the second switching unit UA4. At this time, the GPIO0 connected to the control pin of the second switching unit UA4 is high level, so that the signal is outputted from the NO normally open channel of the second switching unit UA4 to SPK_RS_L and SPK_RS_R, respectively passing through the coupling capacitors CA55 and CA56, and then through the series current limiting resistors RA66 and RA69, and then outputted to the C1 pins of the audio power amplifiers UA5 and UA6, and then connected to the built-in speakers from the C3 and A3 pins of the audio power amplifiers. The 21st-pin recording input connector of the mono sound card chip UA1 is connected to the 4th-pin common input terminal of the first switching unit UA3 through the coupling capacitor CA8. At this time, the GPIO3 connected to the control pin of the first switching unit UA3 is at a low level, so that the signal is output from the NC normally closed channel of the first switching unit UA3 to INT_MIC, and then connected to the built-in microphone after passing through the magnetic bead FBA1.

[0034] When the earphone is plugged in, the GPIO2 of the mono sound card chip UA1 is detected as a low level, and GPIO0 is controlled to be a low level and GPIO3 is a high level. The low level of GPIO0 changes the common terminal signal connection of the second switching unit UA4 from the NO normally open channel to the NC normally closed channel, and connects HP_L and HP_R to HPOUT_L and HPOUT_R, and then passes through the coupling capacitors CA16 and CA17 respectively, and then through the series current limiting resistors RA10, RA11 and the magnetic beads FBA2 and FBA3 to the audio signals HPOUT_L_CON and HPOUT_R_CON of the external earphone. The high level of GPIO3 changes the common terminal signal connection of the first switching unit UA3 from the NC normally closed channel to the NO normally open channel, and connects MIC_IN to HP_MIC, and connects to the recording input signal HP_MIC1_CON of the external earphone through the magnetic bead FBA4. Therefore, it is possible to use a mono sound card chip to do a multi-channel interface function, and can automatically switch between built-in and external by detecting the earphone insertion situation.

[0035] The utility model also provides a terminal device, wherein the terminal device adopts the audio switching circuit described in any one of the above embodiments.

[0036] The utility model has the advantages that, through the monophonic sound card chip and the two switching units, the multi-channel audio output interface can be freely selected, thus saving the cost.

[0037] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An audio switching circuit, characterized in that: The circuit includes a mono sound card chip, a first switching unit, a second switching unit, a first audio playback unit, and a second audio playback unit. One end of the mono sound card chip is connected to the earphone, and the other end is respectively connected to the first switching unit and the second switching unit. The first switching unit and the second switching unit are respectively connected to the input and output signals of the first audio playback unit and the second audio playback unit. When the earphone is not inserted, the mono sound card chip enables the first audio playback unit to work through the first switching unit and the second switching unit. When the earphone is inserted, the mono sound card chip enables the second audio playback unit to work through the first switching unit and the second switching unit.

2. The audio switching circuit according to claim 1, characterized in that: The first audio playback unit includes a built-in microphone and / or a built-in speaker.

3. The audio switching circuit according to claim 2, characterized in that: The second audio playback unit includes an external headphone interface.

4. The audio switching circuit according to claim 3, characterized in that: The second audio playback unit includes a recording input connector for an external headset. When the headset is inserted, the mono sound card chip connects the external headset interface and the recording input connector for the external headset via the first switching unit and the second switching unit.

5. The audio switching circuit according to claim 4, characterized in that: The recording input connector is connected to the first switching unit.

6. The audio switching circuit according to claim 4, characterized in that: The second audio playback unit includes a two-in-one interface of an external headphone interface and a microphone input interface.

7. The audio switching circuit according to claim 1, characterized in that: The mono sound card chip adopts CJC6811A chip.

8. The audio switching circuit according to claim 5, characterized in that: The circuit also includes a first signal processing circuit and a second signal processing circuit. When the earphone is not inserted, the mono sound card chip is at a high level, the mono sound card chip is connected to the second switching unit and the first switching unit, the second switching unit is connected to the built-in speaker through the second signal processing circuit, and the first switching unit is connected to the built-in microphone through the first signal processing circuit; when the earphone is inserted, the mono sound card chip is at a low level, the mono sound card chip is connected to the second switching unit and the first switching unit, the second switching unit is connected to the external earphone interface through the second signal processing circuit, and the first switching unit is connected to the recording input connector of the external earphone through the first signal processing circuit.

9. The audio switching circuit according to claim 8, characterized in that: The first signal processing circuit includes a magnetic bead, and the second signal processing circuit includes coupling capacitors CA55, CA56, current limiting resistors RA66, RA69 and audio power amplifiers UA5, UA6, one end of the coupling capacitor CA55 is connected to the second switching unit, and the other end is connected to one end of the current limiting resistor RA66, and the other end of the current limiting resistor RA66 is connected to the audio power amplifier UA5; one end of the capacitor CA56 is connected to the second switching unit, and the other end is connected to one end of the current limiting resistor RA69, and the other end of the current limiting resistor RA69 is connected to the audio power amplifier UA6.

10. A terminal device, characterized in that: The terminal device comprises the audio switching circuit according to any one of claims 1-9.

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