A power supply circuit and electronic device

Abstract

The present disclosure relates to a power supply circuit and an electronic device. The power supply circuit comprises an output circuit, a first power supply connection end, a first output end and a first input end; the first power supply connection end is connected with the power supply circuit, and the first output end is connected with a second power supply end of a multimedia switch module in the electronic device; a control circuit comprises a second input end, a third input end and a second output end; the second input end is connected with a controller, the third input end is connected with a charging end, and the second output end is connected with the first input end; the control circuit is used for controlling the output circuit to be in a first state when the electronic device is in a shutdown state and is not charging, and the output circuit stops supplying power to the second power supply end of the multimedia switch module in the first state; and the control circuit is used for controlling the output circuit to be in a second state when the electronic device is in the shutdown state and is charging, and the output circuit supplies power to the second power supply end of the multimedia switch module in the second state.

Description

Technical Field

[0001] This disclosure relates to the field of electronic circuit technology, and in particular to a power supply circuit and electronic device. Background Technology

[0002] With the continuous development of electronic circuit technology, its importance in electronic devices is increasing. Electronic devices typically have charging interfaces, such as the USB Type-C interface. This interface integrates charging and headphone connection functions; it can be used for charging and also serves as a connection interface for headphones, allowing data to be sent to the headphones for audio playback.

[0003] The electronic device also features a multimedia switch module that connects to a USB Type-C port to enable audio playback. Utility Model Content

[0004] This disclosure provides a power supply circuit and an electronic device.

[0005] A first aspect of this disclosure provides a power supply circuit, comprising: an output circuit including a first power connection terminal, a first output terminal, and a first input terminal; wherein the first power connection terminal is connected to the power supply circuit, and the first output terminal is connected to a second power supply terminal of a multimedia switch module in the electronic device; a control circuit including a second input terminal, a third input terminal, and a second output terminal, wherein the second input terminal is connected to a controller, the third input terminal is connected to a charging terminal, and the second output terminal is connected to the first input terminal; the charging terminal is used to connect to the power supply terminal of a charger during charging; wherein the control circuit is used at least to control the output circuit to be in a first state when the electronic device is in a powered-off state and not charging, wherein the output circuit stops supplying power to the second power supply terminal of the multimedia switch module in the first state; and to control the output circuit to be in a second state when the electronic device is in a powered-off state and charging, wherein the output circuit supplies power to the second power supply terminal of the multimedia switch module in the second state.

[0006] In one embodiment, the control circuit is further configured to control the output circuit to be in the second state when the electronic device is in the powered-on state.

[0007] In one embodiment, when the electronic device is powered off and not charging, the signal input to the second input terminal by the controller is a low-level signal, and the input signal to the third input terminal is a low-level signal; the output circuit is in the first state.

[0008] In one embodiment, when the electronic device is powered off and charging, the signal input to the second input terminal by the controller is a high-level signal, and the input signal to the third input terminal is a low-level signal; the output circuit is in the second state.

[0009] In one embodiment, when the electronic device is powered on, the signal input from the controller to the second input terminal is a high-level signal; the output circuit is in the second state.

[0010] In one embodiment, the control circuit includes: an inverter circuit, including a second input terminal and a third input terminal, wherein the third input terminal serves as a reference voltage terminal of the inverter circuit; and a wire branch, one end of which serves as the second input terminal and the other end of which serves as the second output terminal.

[0011] In one embodiment, the inverter circuit includes: a first controlled switch, the source of which serves as the third input terminal, and the gate of which serves as the second input terminal and is connected to the control; a second controlled switch, the source of which is grounded, and the gate of which is connected to the gate of the first controlled switch; and the drain of which is connected to the drain of the first controlled switch and serves as the second output terminal.

[0012] In one embodiment, the control circuit further includes: a first unidirectional conducting device located in the wire branch, with its positive terminal connected to the controller and its negative terminal serving as the second output terminal.

[0013] In one embodiment, the control circuit further includes a second unidirectional conducting device, the positive terminal of which is connected to the output terminal of the inverter, and the negative terminal of which serves as the second output terminal.

[0014] In one embodiment, the power supply circuit further includes: a voltage regulator circuit, including a fourth input terminal and a third output terminal; wherein the fourth input terminal is used to connect to the charging terminal during charging; and the third output terminal is connected to the third input terminal of the control circuit.

[0015] In one embodiment, the voltage difference between the voltage input to the third input terminal of the voltage regulator circuit and the voltage input to the second input terminal of the controller is less than a preset value.

[0016] In one embodiment, the voltage regulator circuit includes: a first resistor, one end of which is connected to the charging terminal; a Zener diode, connected in series with the first resistor, wherein the positive terminal of the Zener diode is grounded and the negative terminal is connected to the other end of the first resistor; a second resistor, connected in series with the first resistor; a third resistor, connected in series with the second resistor, and the second resistor and the third resistor connected in series are connected in parallel with the Zener diode; wherein the connection point of the second resistor and the third resistor is connected to the third input terminal.

[0017] In one embodiment, the output circuit includes: a third controlled switch, with its gate serving as the first input terminal and its source grounded; a fourth resistor, with its two ends connected to the first power supply terminal and the drain of the third controlled switch, respectively; a fourth controlled switch, with its gate connected to the drain of the third controlled switch and its source grounded; and a fifth resistor, with its two ends connected to the first power supply terminal and the drain of the fourth controlled switch, respectively; wherein the end of the fifth resistor connected to the drain of the fourth controlled switch serves as the first output terminal.

[0018] A second aspect of this disclosure provides an electronic device, including: a controller; a charging interface having a charging end, the charging end being configured to connect to a power supply end of a charger during charging; a multimedia switch module having a second power supply end; and a power supply circuit as described in any of the above embodiments.

[0019] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0020] The power supply circuit in this embodiment includes a control circuit and an output circuit. The input of the control circuit can be determined by whether the controller and the charging terminal are connected to a charger for charging. Different inputs to the control circuit result in different outputs of the control circuit, and thus different control effects on the output circuit. This allows for control of the output circuit and adjustment of whether the output circuit supplies power to the multimedia switch module.

[0021] This control circuit can, at least when the electronic device is powered off and not charging, stop supplying power to the second power terminal of the multimedia switch module, thus disconnecting the power to the multimedia switch module and resetting all its connection terminals. Conversely, when the electronic device is powered off and charging, the control circuit can supply power to the second power terminal of the multimedia switch module, enabling charging while powered off without affecting normal charging. This method reduces the risk of high current damage to interfaces in the multimedia switch module that are connected to ground (such as auxiliary signal line pins) while still connected to the charging terminal, thus reducing component damage and improving the lifespan and safety of the multimedia switch module. Furthermore, since power supply to the multimedia switch module is stopped when powered off, the power consumption of the multimedia switch module in this state is also reduced, thereby lowering the power consumption of the electronic device during shutdown.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0024] Figure 1 This is a schematic diagram of a circuit according to an exemplary embodiment;

[0025] Figure 2 This is a schematic diagram illustrating a short circuit according to an exemplary embodiment;

[0026] Figure 3 This is a schematic diagram of a power supply circuit according to an exemplary embodiment. Detailed Implementation

[0027] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0028] refer to Figure 1 This is a schematic diagram of a circuit. Figure 1The diagram illustrates the connection between a USB interface and a multimedia switch module in an electronic device. This circuit can be used for charging and information transmission, including connecting headphones for audio signal transmission.

[0029] The VCC pin is the power supply pin for multimedia switch module A. VSYS is the output terminal of the power supply circuit of the electronic device, which is connected to the VCC pin and is used to supply power to multimedia switch module A.

[0030] Both the multimedia switch module A and the USB interface have signal transmission terminals, which may include, for example... Figure 1 The DN and DP pins shown can be denoted as D- (negative) and D+ (positive). The DN and DP pins can be used for differential signal transmission.

[0031] The electronic device also includes a controller B, which may also include a signal transmission terminal, such as... Figure 1 The DN and DP pins are shown in the diagram.

[0032] like Figure 1 As shown, multimedia switch module A also includes DN_L and DN_R pins. The DN_L pin in multimedia switch module A is connected to the DN pin in the USB interface, and the DN_R pin is connected to the DP pin in the USB interface. The DN pin in multimedia switch module A is connected to the DN pin in controller B, and the DN_R pin is connected to the DP pin in controller B.

[0033] Both the multimedia switch module A and the USB interface include SBU and VBUS pins. The SBU pin can be used as an auxiliary signal pin to transmit additional function signals, such as audio and video signals. The SBU pin can include SBU1 and SBU2 pins.

[0034] The VBUS pin serves as a power supply pin, used to transmit DC power. It can be used to charge electronic devices and power headphones when connected.

[0035] The USB interface here can include a Type-C interface as well as other types of interfaces including DN_L pins, DN_R pins, VBUS pins, SBU1 pins, and SBU2 pins.

[0036] When multimedia switch module A is powered on, i.e., when VSYS supplies power to the VCC pin, the DN_L pin and DN pin of multimedia switch module A are connected, and the DN_R pin and DP pin of multimedia switch module A are connected. This establishes the connection between multimedia switch module A, controller B, and the signal transmission terminals in the USB interface. The SBU pin is in a high-impedance state by default. When there is no power supply voltage to the VCC pin, the DN pin, DP pin, and SBU pin are all in a high-impedance state by default.

[0037] Normally, VCC power is always available, supplying power both when the electronic device is powered on and off, which increases the power consumption when the device is off. Furthermore, before the headphones are connected to the USB interface, the SBU pin is floating and not grounded, resulting in a high-impedance state. After the headphones are plugged in, the SBU pin is grounded, either SBU1 or SBU2, allowing the headphones to function properly. If the headphones are plugged into the USB interface and then unplugged while the device is powered on, the device can automatically restore the grounded SBU pin to a high-impedance state through system settings.

[0038] If the headphones are plugged into the electronic device before it is powered off, and then unplugged after the device is powered off, the SBU1 or SBU2 pin will remain grounded. Since the device is powered off, it cannot control the grounded SBU pin to return to a high-impedance state.

[0039] Figure 1 It may also include other components, such as an audio codec C, which is also connected to the multimedia switch module A, in a connection manner as follows: Figure 1 As shown. The pinouts and connections of each component can be found in the reference diagram. Figure 1 .

[0040] like Figure 2 The diagram illustrates a short circuit. Because the SBU and VBUS pins of the USB interface are adjacent and prone to corrosion, when the SBU and VBUS pins are shorted due to corrosion, if the electronic device is powered off, the headphones are unplugged, and then the USB cable is plugged in for charging, the voltage on the VBUS pin will be connected to ground through the grounded SBU pin because either the SBU1 or SBU2 pin is shorted to ground. The large current during charging can damage the grounded SBU pin, causing malfunction of the audio switch.

[0041] refer to Figure 3 This is a schematic diagram of a power supply circuit, which includes:

[0042] Output circuit 1 includes a first power connection terminal 101, a first output terminal 102, and a first input terminal 103; wherein, the first power connection terminal 101 is connected to the power supply circuit, and the first output terminal 102 is connected to the second power supply terminal of the multimedia switch module A in the electronic device. The second power supply terminal is... Figure 1 The VCC pin is shown.

[0043] The control circuit 2 includes a second input terminal 201, a third input terminal 202, and a second output terminal 203. The second input terminal 201 is connected to the controller B, the third input terminal 202 is connected to the charging terminal, and the second output terminal 203 is connected to the first input terminal 103. The charging terminal is used to connect to the power supply terminal of the charger during charging.

[0044] Among them, the control circuit 2 is used at least when the electronic device is in a powered-off state and not being charged, the control output circuit 1 is in a first state, and the output circuit stops supplying power to the second power terminal of the multimedia switch module A in the first state; when the electronic device is in a powered-off state and being charged, the control output circuit 1 is in a second state, and the output circuit supplies power to the second power terminal of the multimedia switch module in the second state.

[0045] Output circuit 1 has a first power connection terminal 101, which is connected to the power supply circuit for connecting to the power supply circuit, thereby facilitating the supply of power to multimedia switch module A. The power supply circuit can be a power supply circuit output from the power supply or controller in the electronic device for supplying power to multimedia switch module A. The supply voltage provided by the power supply circuit can be referenced... Figure 1 The VSYS diagram shows the first output terminal 102, which serves as the output terminal of the power supply circuit and is connected to the power supply pin of the multimedia switch module A. The power supply pin of the multimedia switch module A is referenced... Figure 1 The voltage output from the first output terminal 102 is the voltage supplied to the multimedia switch module A. The first input terminal 103 serves as the control terminal of the output circuit 1, controlling whether the output circuit 1 supplies power to the power pin of the multimedia switch module A.

[0046] Output circuit 1 acts as a switch. It can transmit the voltage provided by VSYS to the power pin of multimedia switch module A according to the control signal transmitted by control circuit 2, or it can stop transmitting the voltage provided by VSYS to the power pin of multimedia switch module A.

[0047] The circuit structure of output circuit 1 is not limited; any circuit that can achieve the above functions is acceptable.

[0048] Control circuit 2 acts as the control circuit for output circuit 1, outputting control signals to control whether output circuit 1 transmits the voltage provided by VSYS to the power pin of multimedia switch module A.

[0049] In control circuit 2, the second input terminal 201 is connected to controller B, the third input terminal 202 is connected to the charging terminal, and the second output terminal 203 is connected to the first input terminal 103. The output of control circuit 2 is affected by the signals input to the second input terminal 201 and the third input terminal 202. The inputs from both the second input terminal 201 and the third input terminal 202 jointly affect the output of control circuit 2; that is, the output of control circuit 2 is determined based on the inputs from both the second input terminal 201 and the third input terminal 202.

[0050] The control circuit 2 has two input terminals, with the second input terminal 201 and the third input terminal 202 serving as the controlled terminals of the control circuit.

[0051] For example, the second input terminal 201 can be connected to a GPIO pin in controller B, which serves as an output pin connected to control circuit 2.

[0052] The charging port can be used to connect to the power supply port of the charger during charging; please refer to [reference needed]. Figure 1 The VBUS pin in the USB interface shown.

[0053] When the electronic device is powered off and not charging, the control circuit 2 can control the output circuit 1 to be in a first state based on the signal input to the control circuit 2 from the controller B and the signal input to the third input terminal 202. In the first state, the output circuit 1 stops supplying power to the second power terminal of the multimedia switch module A. Alternatively, when the electronic device is powered off and charging, the output circuit 1 can be controlled to be in a second state based on the signal input to the control circuit 2 from the controller B and the signal input to the third input terminal 202. In the second state, the output circuit 1 supplies power to the second power terminal of the multimedia switch module.

[0054] The circuit structure of the control circuit 2 is not limited; any circuit that has a second input terminal 201, a third input terminal 202, and a second output terminal 203 and can perform the above functions is acceptable.

[0055] The power supply circuit in this embodiment includes a control circuit and an output circuit. The input of the control circuit can be determined by whether the controller and the charging terminal are connected to a charger for charging. Different inputs to the control circuit result in different outputs of the control circuit, which in turn affect the control effect on the output circuit. This allows for the control of the output circuit, adjusting its state, and thus controlling whether to supply power to the multimedia switch module.

[0056] This control circuit can, at least when the electronic device is powered off and not charging, control the output circuit to stop supplying power to the second power terminal of the multimedia switch module. This achieves power-off of the multimedia switch module, resetting all connection terminals of the multimedia switch module, including the grounded SBU pin, from ground to a high-impedance state. Conversely, when the electronic device is powered off and charging, the control circuit can supply power to the second power terminal of the multimedia switch module, thus enabling charging functionality in the powered-off state without affecting normal charging.

[0057] This solution reduces the likelihood of high-current damage to interfaces caused by charging when some interfaces (such as the SBU pin) in the multimedia switch module are grounded and still connected to the charging terminal, thus reducing device damage and improving the lifespan and safety of the multimedia switch module. Furthermore, since power supply to the multimedia switch module is stopped when the device is off, its power consumption is also reduced, thereby lowering the power consumption of the electronic device during shutdown.

[0058] In one embodiment, the control circuit 2 is further configured to control the output circuit 1 to be in a second state when the electronic device is powered on, and in the second state, the output circuit 1 supplies power to the second power supply terminal of the multimedia switch module A.

[0059] When powered on, output circuit 1 is in the second state, which can supply power to multimedia switch module A, thereby ensuring the normal operation of multimedia switch module A and reducing the impact on the normal use of multimedia switch module A.

[0060] In this embodiment, the power supply circuit can supply power to the second power terminal of the multimedia switch module A through the control circuit 2, which controls the output circuit 1, when the electronic device is powered on. It can also supply power to the second power terminal of the multimedia switch module A through the control circuit 2, when the electronic device is powered off and charging. Furthermore, it can stop supplying power to the second power terminal of the multimedia switch module A through the control circuit 2, when the electronic device is powered off and not charging. This power supply circuit can support various applications in different scenarios without interfering with each other or affecting normal use in any scenario. It also reduces the likelihood of damage to the multimedia switch module A, improving the user experience.

[0061] In one embodiment, when the electronic device is powered off and not charging, the controller no longer supplies voltage to the control circuit 2, and the signal input to the second input terminal 201 can be recorded as a low-level signal. When not charging, the charger also does not input electrical signals to the control circuit 2, and the input signal to the third input terminal 202 is recorded as a low-level signal. In this case, the signal output by the control circuit 2 is a low-level signal, and the control output circuit 1 is in a first state. In the first state, since the electronic device is powered off, the multimedia switch module A no longer works, and therefore, there is no need to supply power to the multimedia switch module A.

[0062] Since the electronic device is powered off when the headphones are plugged into the USB port, and charging requires unplugging the headphones first, the output circuit 1 is already adjusted to the first state after the electronic device is powered off and before the headphones are unplugged. Output circuit 1 disconnects the power supply to the multimedia switch module A, causing the grounded SBU pin in the multimedia switch module A to reset from ground to a high-impedance state. This prevents the VBUS pin from shorting to ground through the SBU pin during subsequent charging, even if the SBU pin and VBUS pin are shorted due to corrosion or other reasons. This reduces the risk of burning out the SBU pin during charging and minimizes the impact on normal headphone use.

[0063] In one embodiment, when the electronic device is powered off and charging, the controller no longer supplies power to the control circuit 2, and the signal input to the second input terminal 201 can be recorded as a low-level signal. During charging, the charger provides charging voltage to the control circuit 2, and the input signal to the third input terminal 202 is recorded as a high-level signal. In this case, the signal output by the control circuit 2 is a high-level signal, and the control output circuit 1 is in the second state to ensure the normal operation of the multimedia switch module A.

[0064] This solution ensures normal charging of electronic devices by restoring the grounded SUB pin in multimedia switch module A to a high-impedance state.

[0065] In one embodiment, when the electronic device is powered on and the controller is operating normally, it can supply power to the control circuit 2. Since there is a supply voltage at the second input terminal 201, the signal input from the controller to the second input terminal 201 is recorded as a high-level signal. In this case, the signal output by the control circuit 2 is a high-level signal, and the control output circuit 1 is in the second state, supplying power to the multimedia switch module A to ensure its normal operation.

[0066] In one embodiment, reference Figure 3 The control circuit includes:

[0067] The inverter circuit 21 includes a second input terminal 201, a third input terminal 202, and a second output terminal 203, wherein the third input terminal 202 serves as the reference voltage terminal of the inverter circuit 21.

[0068] The wire branch 22 has one end serving as the second input terminal 201 and the other end serving as the second output terminal 203.

[0069] The control circuit 2 includes an inverter circuit 21, which can be an inverter circuit formed by a MOS transistor, an inverter circuit formed by a transistor, or a circuit with inverting function formed by other electronic components.

[0070] The inverter circuit 21 has an output terminal, an output terminal and a reference voltage terminal. The second input terminal 201 is used as the input terminal of the inverter circuit 21, the third input terminal 202 is used as the reference voltage terminal of the inverter circuit 21, and the second output terminal 203 is used as the output terminal of the inverter circuit 21.

[0071] The inverter circuit 21 has a reverse function, and its output is opposite to its input. In this embodiment, the output of the inverter circuit 21 is also related to the third input terminal 202. The second input terminal 201 and the third input terminal 202 together determine the output of the inverter circuit 21.

[0072] For example, when the electronic device is powered off and not charging, the signal input from the controller to the second input terminal 201 is a low-level signal, and the input signal to the third input terminal 202 is also a low-level signal. In this case, the inverter circuit 21 has no reference voltage, so it no longer functions and outputs a low-level signal. When the inverter circuit 21 outputs a low-level signal, the output circuit 1 is in the first state.

[0073] For example, when the electronic device is powered off and charging, the signal input from the controller to the second input terminal 201 is a low-level signal, while the input signal to the third input terminal 202 is a high-level signal due to the input charging voltage. In this situation, the inverter circuit 21 has a reference voltage and is activated, so the inverter circuit 21 outputs a high-level signal. When the inverter circuit 21 outputs a high-level signal, the output circuit 1 is in the second state.

[0074] For example, when the electronic device is powered on, the signal input from the controller to the second input terminal 201 is a high-level signal. Due to the presence of the wire branch 22, the wire branch 22 short-circuits the inverter circuit. Regardless of whether the input signal to the third input terminal 20 is a high-level signal or a low-level signal, the inverter circuit 21 outputs a high-level signal. When the inverter circuit 21 outputs a high-level signal, the output circuit 1 is in the second state.

[0075] In one embodiment, reference Figure 3 The inverter circuit 21 includes:

[0076] The first controlled switch T1 has its source as the third input terminal 202 and its gate as the second input terminal connected to the controller.

[0077] The second controlled switch T2 has its source grounded and its gate connected to the gate of the first controlled switch T1. The drain of the second controlled switch T2 is connected to the drain of the first controlled switch T1 and serves as the second output terminal 203.

[0078] The first controlled switch T1 is an enhancement-mode P-channel MOSFET (PMOS), and the second controlled switch T2 is an enhancement-mode N-channel MOSFET (NMOS).

[0079] The first controlled switch T1 and the second controlled switch T2 form an inverter circuit 21. When the signals input to the second input terminal 201 and the third input terminal 202 are both low-level signals, the electronic device is in a powered-off state and not charging. In this situation, the first controlled switch T1 is off, the second controlled switch T2 is off, so the second output terminal 203 of the inverter circuit 21 outputs a low-level signal. The output circuit 1, based on the low-level signal output by the control circuit 2, is in a first state and stops supplying power to the multimedia switch module A.

[0080] When the signal input to the second input terminal 201 is a low-level signal and the signal input to the third input terminal 202 is a high-level signal, the electronic device is in a powered-off state and a charging state. In this case, the first controlled switch T1 is turned on and the second controlled switch T2 is turned off, so the second output terminal 203 of the inverter circuit 21 outputs a high-level signal. The output circuit 1 is in the second state according to the low-level signal output by the control circuit 2 and supplies power to the multimedia switch module A.

[0081] When the signal input to the second input terminal 201 is a high-level signal, the electronic device is in the powered-on state. In this case, the first controlled switch T1 is off, and the second controlled switch T2 is on. Due to the presence of the wire branch 22, the inverter circuit 21 is short-circuited, so the high-level signal at the second input terminal 201 is directly input as the output signal of the control circuit 2. The output circuit 1, based on the high-level signal output by the control circuit 2, is in the second state and supplies power to the multimedia switch module A.

[0082] In one embodiment, the inverter circuit 21 may further include:

[0083] The transistor has its collector as the third input terminal 202, its base as the second input terminal 201, its emitter grounded, and its collector as the second output terminal 203.

[0084] One end of the wire branch 22 is connected to the base of the transistor, and the other end serves as the second output terminal 203.

[0085] When the electronic device is powered off and not charging, the second input terminal 201 and the third input terminal 202 both receive a high level, the transistor is turned on, and the second output terminal 203 outputs a low level. When the electronic device is powered off and charging, the second input terminal 201 receives a low level, the third input terminal 202 receives a high level, the transistor is turned on, and the second output terminal 203 outputs a high level. When the electronic device is powered on, the second input terminal 201 receives a high level. Due to the presence of the wire branch 22, the transistor is short-circuited. Regardless of whether the third input terminal 202 receives a high or low level, the control circuit 2 always outputs a high level, using the level input from the second input terminal 201 as the output of the control circuit 2.

[0086] For example, resistors are also connected to the base and collector of the transistor.

[0087] In one embodiment, the control circuit 2 further includes:

[0088] The first unidirectional conducting device D1 is located in the wire branch 22, with its positive terminal connected to the controller and its negative terminal serving as the second output terminal 203.

[0089] The first unidirectional conducting device D1 can be a diode or other device with directional conductivity. The first unidirectional conducting device D1 has the characteristic of unidirectional conduction, so by setting the first unidirectional conducting device D1, the reverse current can be prevented and the circuit can be protected.

[0090] In one embodiment, the control circuit further includes:

[0091] The second unidirectional conducting device D2 has its positive terminal connected to the output terminal of the inverter circuit 21, and its negative terminal used as the second output terminal 203.

[0092] The second unidirectional conducting device D2 can be a diode or other device with directional conductivity. The second unidirectional conducting device D2 has the characteristic of unidirectional conduction, so by setting the second unidirectional conducting device D2, the reverse current can be prevented and the circuit can be protected.

[0093] In one embodiment, the power supply circuit further includes:

[0094] The voltage regulator circuit 3 includes a fourth input terminal 301 and a third output terminal 302.

[0095] The fourth input terminal 301 is used to connect to the charging terminal during charging; the third output terminal 302 is connected to the third input terminal 202 of the control circuit 2.

[0096] The voltage regulator circuit 3 is used to stabilize the voltage input to the third input terminal 202. The voltage input to the charging terminal may fluctuate. The voltage regulator circuit 3 can keep the voltage input to the third input terminal 202 stable even when the voltage input to the charging terminal fluctuates, thereby reducing the impact of voltage fluctuations at the charging terminal on the control circuit.

[0097] The voltage regulator circuit 3 can be any type of circuit with voltage regulation function, and the circuit structure is not limited, such as a voltage regulator circuit formed by a Zener diode.

[0098] The voltage difference between the voltage input to the third input terminal 202 of the voltage regulator circuit 3 and the voltage input to the second input terminal 201 of the controller is less than a preset value. This allows the output voltage of the output circuit 1 to be closer, thereby better controlling the state of the output circuit 1.

[0099] For example, the voltage input to the third input terminal 202 of the voltage regulator circuit 3 is the same as the voltage input to the second input terminal 201 of the controller.

[0100] refer to Figure 3 The voltage regulator circuit includes:

[0101] The first resistor R1 has one end connected to the charging terminal;

[0102] A Zener diode U1 is connected in series with a first resistor R1, wherein the positive terminal of the Zener diode is grounded and the negative terminal is connected to the other end of the first resistor R1;

[0103] The second resistor R2 is connected in series with the first resistor R1;

[0104] The third resistor R3 is connected in series with the second resistor R2, and the second resistor R2 and the third resistor R3 connected in series are connected in parallel with the Zener diode U1; wherein, the connection point of the second resistor R2 and the third resistor R3 is connected to the third input terminal 202.

[0105] The positive terminal of a Zener diode can also be referred to as the anode, and the negative terminal of a Zener diode can also be referred to as the cathode. A Zener diode can also be connected to a first resistor R1 with a reference terminal.

[0106] For example, the reference voltage of the Zener diode can be 2.5V.

[0107] In one embodiment, the output circuit 1 includes:

[0108] The third controlled switch T3 has its gate as the first input terminal 103 and its source grounded.

[0109] The fourth resistor R4 is connected at both ends to the first power supply connection terminal 101 and the drain of the third controlled switch T3, respectively.

[0110] The gate of the fourth controlled switch T4 is connected to the drain of the third controlled switch T3, and its source is grounded.

[0111] The fifth resistor R5 is connected at both ends to the first power supply connection terminal 101 and the drain of the fourth controlled switch T4, respectively.

[0112] Among them, the end of the fifth resistor R5 connected to the drain of the fourth controlled switch T4 serves as the first output terminal 102.

[0113] The third controlled switch T3 and the fourth controlled switch T4 can be NMOS.

[0114] When control circuit 2 outputs a high level, the third controlled switch T3 is turned on. The fourth resistor R4 prevents the first power supply connection terminal 101 from being short-circuited. The gate voltage of the fourth controlled switch T4 is low, so the fourth controlled switch T4 is turned off, and output circuit 1 is in the second state. The first power supply connection terminal 101 supplies power to the second power supply terminal, i.e., the VCC pin, through the fifth resistor R5.

[0115] When control circuit 2 outputs a low level, the third controlled switch T3 is turned off. The gate of the fourth controlled switch T4 is connected in series with the fourth resistor R4, so the voltage at the gate of the fourth controlled switch T4 is high, and the fourth controlled switch T4 is turned on. The first power supply connection terminal 101 is grounded through the fifth resistor R5, short-circuiting the second power supply terminal, i.e., the VCC pin, and the output circuit 1 is in the first state. This disconnects the power supply from the output circuit 1 to the multimedia switch module A.

[0116] Figure 3 One output circuit is shown, but it can also include other connection relationships and output circuits of electronic components, which can realize the switching between the first state and the second state.

[0117] In one embodiment, an electronic device is also provided, comprising:

[0118] Controller;

[0119] The charging interface has a charging end, which is used to connect to the power supply end of the charger during charging.

[0120] A multimedia switch module with a second power supply terminal;

[0121] The power supply circuit in any of the above embodiments.

[0122] The controller, charging port, and multimedia switch module can be referenced. Figure 1 The part shown.

[0123] In one embodiment, reference Figure 3 It also provides a power supply circuit, including a hardware reset circuit for a multimedia switch module.

[0124] GPIO is initially low. When the machine is powered on, the CPU pulls GPIO high, and T3 conducts VSYS connected to the VCC pin of the Audio Switch to supply power to the Audio Switch. After the machine is powered off, GPIO is reset to low, and the VCC of the Audio Switch has no voltage, thus performing a hard reset. DN_L, DP_R, SBU1, and SBU2 are all in a high-impedance state by default.

[0125] Considering that the Audio Switch's DN_L and DP_R need to be connected to DN and DP during USB download and charging in the factory, the circuit in the diagram above can also implement the following logic: T1 is an enhancement-type PMOS (conducts when Vgs < 0), and T2, T3, and T4 (conducts when Vgs > 0) are the same type of enhancement-type NMOS. The key parameter is that the value of V1 = 2.5 * R3 / (R2 + R3) is the same as the high-level voltage of the GPIO.

[0126] When the factory is downloading via USB and charging the mobile phone, the voltage on VBUS is greater than or equal to 5V. V1 has a voltage output, GPIO is low, T1 is turned on, T2 is turned off, the gate voltage of T3 is V1 minus the forward voltage drop of D2, T3 is turned on, T4 is turned off, the drain of T4 is connected to the VCC power supply pin of the Audio Switch, VSYS supplies power to the Audio Switch, and DN_L and DP_R are connected to DN and DP.

[0127] After the machine is powered on, the CPU pulls the GPIO high, T1 is cut off, T2 is turned on, T3 is turned on, T4 is cut off, V1 disconnects the control of T3, and VSYS is connected to the VCC pin of the Audio Switch to supply power to the Audio Switch.

[0128] After the machine is powered off, GPIO is reset to low level, VBUS has no voltage, and the Audio Switch's VCC has no voltage, thus undergoing a hard reset. DN_L, DP_R, SBU1, and SBU2 are all in high impedance state by default.

[0129] The solution in this embodiment can reduce the power consumption when the phone is turned off, thereby resetting the audio switch hardware and preventing damage to the device.

[0130] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0131] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A power supply circuit, characterized in that, include: The output circuit includes a first power connection terminal, a first output terminal, and a first input terminal; wherein the first power connection terminal is connected to the power supply circuit, and the first output terminal is connected to the second power supply terminal of the multimedia switch module in the electronic device. The control circuit includes a second input terminal, a third input terminal, and a second output terminal. The second input terminal is connected to the controller, the third input terminal is connected to the charging terminal, and the second output terminal is connected to the first input terminal. The charging terminal is used to connect to the power supply terminal of the charger during charging. The control circuit is used at least to control the output circuit to be in a first state when the electronic device is in a powered-off state and not being charged, and the output circuit stops supplying power to the second power terminal of the multimedia switch module in the first state. When the electronic device is powered off and charging, the output circuit is controlled to be in a second state, and the output circuit supplies power to the second power terminal of the multimedia switch module in the second state.

2. The power supply circuit according to claim 1, characterized in that, The control circuit is also used to control the output circuit to be in the second state when the electronic device is powered on.

3. The power supply circuit according to claim 1, characterized in that, When the electronic device is powered off and not being charged, the signal input to the second input terminal by the controller is a low-level signal, and the input signal to the third input terminal is a low-level signal; The output circuit is in the first state.

4. The power supply circuit according to claim 1, characterized in that, When the electronic device is powered off and charging, the signal input to the second input terminal by the controller is a low-level signal, and the input signal to the third input terminal is a high-level signal. The output circuit is in the second state.

5. The power supply circuit according to claim 1, characterized in that, When the electronic device is powered on, the signal input to the second input terminal by the controller is a high-level signal; The output circuit is in the second state.

6. The power supply circuit according to claim 1, characterized in that, The control circuit includes: An inverter circuit includes a second input terminal, a third input terminal, and a second output terminal, wherein the third input terminal serves as a reference voltage terminal for the inverter circuit. One end of the wire branch serves as the second input terminal, and the other end serves as the second output terminal.

7. The power supply circuit according to claim 6, characterized in that, The inverter circuit includes: A first controlled switch, the source of which serves as the third input terminal, and the gate of which serves as the second input terminal and is connected to the controller; The second controlled switch has its source grounded and its gate connected to the gate of the first controlled switch; the drain of the second controlled switch is connected to the drain of the first controlled switch and serves as the second output terminal.

8. The power supply circuit according to claim 6, characterized in that, The control circuit also includes: The first unidirectional conducting device is located in the wire branch, with its positive terminal connected to the controller and its negative terminal serving as the second output terminal.

9. The power supply circuit according to claim 6, characterized in that, The control circuit also includes: The second unidirectional conducting device has its positive terminal connected to the output terminal of the inverter circuit, and its negative terminal serving as the second output terminal.

10. The power supply circuit according to claim 1, characterized in that, The power supply circuit also includes: The voltage regulator circuit includes a fourth input terminal and a third output terminal; The fourth input terminal is used to connect to the charging terminal during charging; the third output terminal is connected to the third input terminal of the control circuit.

11. The power supply circuit according to claim 10, characterized in that, The voltage difference between the voltage input to the third input terminal of the voltage regulator circuit and the voltage input to the second input terminal of the controller is less than a preset value.

12. The power supply circuit according to claim 10, characterized in that, The voltage regulator circuit includes: The first resistor has one end connected to the charging terminal; A Zener diode is connected in series with the first resistor, wherein the positive terminal of the Zener diode is grounded and the negative terminal is connected to the other end of the first resistor; The second resistor is connected in series with the first resistor; A third resistor is connected in series with the second resistor, and the second and third resistors connected in series are connected in parallel with the Zener diode; wherein the connection point of the second and third resistors is connected to the third input terminal.

13. The power supply circuit according to claim 1, characterized in that, The output circuit includes: The third controlled switch has its gate as the first input terminal and its source grounded. The fourth resistor has its two ends connected to the first power supply terminal and the drain of the third controlled switch, respectively. The fourth controlled switch has its gate connected to the drain of the third controlled switch and its source grounded. The fifth resistor has its two ends connected to the first power supply connection terminal and the drain of the fourth controlled switch, respectively; wherein the end of the fifth resistor connected to the drain of the fourth controlled switch serves as the first output terminal.

14. An electronic device, characterized in that, include: Controller; A charging interface having a charging end, the charging end being used to connect to the power supply end of the charger during charging; A multimedia switch module with a second power supply terminal; The power supply circuit according to any one of claims 1 to 13.

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