A three-terminal power input and output switching circuit and device

Abstract

The present invention relates to the field of electronic circuit technology, and specifically to a three-terminal power input and output switching circuit and device, wherein the switching circuit includes three input and output terminals, a first switch circuit, a second switch circuit and a switch control circuit. The switch control circuit is connected to the two input and output terminals, the first switch circuit and the second switch circuit respectively. The control circuit is used to turn on the first switch circuit or the second switch circuit under the triggering of the power signal when the first input and output terminal or the second input and output terminal has power access, so that the power signal is output from the third input and output terminal, so that when any charging interface is connected to the power supply, the device can be charged. Or when the first input and output terminal and the second input and output terminal have power signals accessed at the same time, the first switch circuit is controlled to be turned on and the second switch circuit is turned off, so that the power signal of the first input and output terminal is preferentially output from the third input and output terminal to charge the electronic device.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a three-terminal power input and output switching circuit and device. Background Art

[0002] Existing communication equipment or electronic equipment are all single-ended charging, but for some special electronic products, such as explosion-proof mobile phones or some outdoor mobile phones, two different types of charging ports are required for charging. For example, explosion-proof mobile phones are usually equipped with a mainstream charging interface, such as a type-c charging interface, and a special charging interface is also provided, so that any charging interface can be selected for charging when in use to meet the charging needs of the explosion-proof mobile phone. At the same time, such mobile phones or electronic devices used by special personnel usually need to be connected to external devices, and the external devices need to be charged through the built-in power supply of the mobile phone or electronic device. If there is only a single interface on the mobile phone or electronic device, it often cannot meet the needs of multiple external devices. Therefore, different external devices generally have different interface types, and a single interface cannot be universal. Therefore, generally two interfaces are provided on explosion-proof mobile phones. When any of the interfaces is inserted into an external device, the explosion-proof mobile phone can be charged, and there is no circuit design that meets this demand in the prior art. Summary of the invention

[0003] The present application provides a three-terminal power input and output switching circuit and device, the purpose of which is to enable one charging interface to be selected for charging when any one of the two charging interfaces is connected to the power supply or the two charging interfaces are connected to the power supply at the same time.

[0004] A three-terminal power input and output switching circuit, comprising a first input and output terminal, a second input and output terminal, a third input and output terminal, a first switch circuit, a second switch circuit and a switch control circuit;

[0005] The first input / output terminal is connected to the third input / output terminal through a first switch circuit, the first switch circuit is used to control the on / off between the first input / output terminal and the third input / output terminal, the second input / output terminal is connected to the third input / output terminal through a second switch circuit, the second switch circuit is used to control the on / off between the second input / output terminal and the third input / output terminal; the switch control circuit is respectively connected to the first input / output terminal, the second input / output terminal, the first switch circuit, and the second switch circuit;

[0006] The control circuit is used to, when a power signal is connected to the first input / output terminal or the second input / output terminal, turn on the first switch circuit or the second switch circuit under the triggering of the power signal, so that the power signal is output from the third input / output terminal; and when a power signal is connected to the first input / output terminal and the second input / output terminal at the same time, control the first switch circuit to turn on and the second switch circuit to turn off, so that the power signal of the first input / output terminal is preferentially output from the third input / output terminal.

[0007] In another embodiment, the control circuit is also used to receive a control signal when a power signal is connected to the third input / output terminal, and control the on / off of the first switch circuit and the second switch circuit, so that the power signal is output from the first input / output terminal or the second input / output terminal.

[0008] In another embodiment, the first switch circuit and the second switch circuit are both transistor switch circuits, which include at least one transistor; the transistor switch circuits each include a first end, a second end and a control end, the first end and the second end are respectively connected to the first input-output end and the third input-output end, and the control end is connected to the switch control circuit, or the first end and the second end are respectively connected to the first input-output end and the third input-output end, and the control end is connected to the switch control circuit.

[0009] In another embodiment, the transistor switching circuit includes a transistor A and a transistor B, the first electrode of the transistor A is connected to the first electrode of the transistor B, the second electrode of the transistor A is the first end of the transistor circuit, the second electrode of the transistor B is the second end of the transistor circuit, and the control electrode of the transistor A and the control electrode of the transistor B are connected to serve as the control end of the transistor circuit.

[0010] In another embodiment, the switch control circuit includes a first switch control circuit and a second switch control circuit;

[0011] The input end of the first switch control circuit is connected to the first input-output end, and the output end thereof is connected to the control end of the first switch circuit, and is used to control the first switch circuit to be turned on under the triggering of the power signal connected to the first input-output end, so that the power signal is output from the third input-output end;

[0012] The input end of the second switch control circuit is connected to the second input-output end, and the output end is connected to the control end of the second switch circuit, and is used to control the conduction of the second switch circuit under the triggering of the power signal connected to the second input-output end, so that the power signal is output from the third input-output end.

[0013] In another embodiment, a third switch control circuit is further included; the input end of the third switch control circuit is connected to the output end of the first switch control circuit, and the input end of the third switch control circuit is connected to the input end of the second switch control circuit; and is used to control the first switch circuit to be turned on and the second switch circuit to be turned off when power signals are connected to the first input-output end and the second input-output end at the same time, so that the power signal of the first input-output end is outputted preferentially from the third input-output end.

[0014] In another embodiment, the first switch control circuit further includes a first switch control terminal, and the second switch control circuit further includes a second switch control terminal;

[0015] When a power signal is connected to the third input / output terminal, the first switch control terminal receives a control signal to turn on the first switch circuit, thereby outputting the power signal from the first input / output terminal; or when a power signal is connected to the third input / output terminal, the second switch control terminal receives a control signal to turn on the second switch circuit, thereby outputting the power signal from the second input / output terminal.

[0016] In another embodiment, the first switch control circuit includes a second resistor, a third resistor, a fourth resistor, a fourth transistor, and a fifth transistor, one end of the second resistor is connected to the first input / output end, and the other end is grounded; the control electrode of the fifth transistor is connected to the first input / output end, the first electrode is grounded, and the second electrode is connected to the control end of the first switch circuit; the first electrode of the fourth transistor is grounded, and the second electrode is also connected to the control end of the first switch circuit, and the control electrode is connected to one end of the third resistor, and the other end of the third resistor is connected to the first switch control end for receiving a control signal; one end of the fourth resistor is connected to the control electrode of the fourth transistor, and the other end is grounded;

[0017] The second switch control circuit includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a first capacitor, a third transistor and a seventh transistor, one end of the ninth resistor is connected to the second input-output end, and the other end is connected to the control electrode of the third transistor, the first electrode of the third transistor is grounded, and the second electrode is connected to the control end of the second switch circuit, the first electrode of the seventh transistor is grounded, and the second electrode is also connected to the control end of the second switch circuit, and its control electrode is connected to one end of the sixth resistor, and the other end of the sixth resistor is connected to the second switch control end for receiving a control signal; one end of the seventh resistor is connected to the control electrode of the seventh transistor, and the other end is grounded; one end of the eighth resistor is connected to the control electrode of the third transistor, and the other end is grounded; one end of the first capacitor is connected to the control electrode of the third transistor, and the other end is grounded;

[0018] The third switch control circuit is a wire, one end of which is connected to the second electrode of the fifth transistor, and the other end of which is connected to the control electrode of the third transistor.

[0019] In another embodiment, a fourth switch control circuit is further included, wherein two ends of the fourth switch control circuit are respectively connected to the first input / output end and the second input / output end, and is used to control the second switch circuit to be turned on preferentially when the first input / output end and the second input / output end are simultaneously connected with a power signal, so that the power signal of the second input / output end is output from the third input / output end;

[0020] The fourth switch control circuit includes a tenth resistor, an eleventh resistor and a sixth transistor, one end of the tenth resistor is connected to the second input-output terminal, and the other end is connected to the control electrode of the sixth transistor, the first electrode of the sixth transistor is grounded, and the second electrode is connected to the first input-output terminal; one end of the eleventh resistor is connected to the control electrode of the sixth transistor, and the other end is grounded.

[0021] A three-terminal power input and output switching device, comprising the three-terminal power input and output switching circuit as described above;

[0022] It also includes three input and output interfaces, which are respectively connected to the first input and output end, the second input and output end, and the third input and output end.

[0023] According to the three-terminal power input and output switching circuit of the above embodiment, it includes a first input and output terminal, a second input and output terminal, a third input and output terminal, a first switch circuit, a second switch circuit and a switch control circuit. The first input and output terminal is connected to the third input and output terminal through the first switch circuit, and the first switch circuit is used to control the on and off between the first input and output terminal and the third input and output terminal. The second input and output terminal is connected to the third input and output terminal through the second switch circuit, and the second switch circuit is used to control the on and off between the second input and output terminal and the third input and output terminal. The switch control circuit is respectively connected to the first input and output terminal, the second input and output terminal, the first switch circuit and the second switch circuit. The control circuit is used to turn on the first switch circuit or the second switch circuit under the triggering of the power signal when the first input and output terminal or the second input and output terminal has power access, so that the power signal is output from the third input and output terminal, so that when any charging interface is connected to the power supply, the device can be charged. Or when the first input / output terminal and the second input / output terminal are connected with power signals at the same time, the first switch circuit is controlled to be turned on and the second switch circuit is turned off, so that the power signal of the first input / output terminal is preferentially output from the third input / output terminal to charge the electronic device. Through the circuit of this embodiment, the electronic device can be provided with two charging interfaces at the same time to meet the needs of special groups of people or personnel in special positions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of a three-terminal power input and output switching circuit according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0026] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0027] The serial numbers assigned to the components in this article, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning.

[0028] In order to meet the needs of some products that need two charging ports for charging, this application provides a three-terminal power input and output switching circuit. When charging, this circuit can realize charging of two input ports. When the double-terminal power input is connected first, it is turned on first. When charging the external device through the electronic product, it can realize charging of two output ports. To meet the needs of some electronic products.

[0029] The transistor in the present application is a three-terminal transistor, and its three terminals are a control electrode, a first electrode, and a second electrode. The transistor can be a bipolar transistor or a field effect transistor, etc. For example, when the transistor is a bipolar transistor, its control electrode refers to the base of the bipolar transistor, the first electrode can be the collector or emitter of the bipolar transistor, and the corresponding second electrode can be the emitter or collector of the bipolar transistor; when the transistor is a field effect transistor, its control electrode refers to the gate of the field effect transistor, the first electrode can be the drain or source of the field effect transistor, and the corresponding second electrode can be the source or drain of the field effect transistor.

[0030] Embodiment 1:

[0031] Please refer to Figure 1The three-terminal power input and output switching circuit of this embodiment includes a first input and output terminal A, a second input and output terminal B, a third input and output terminal C, a first switch circuit 102, a second switch circuit 101 and a switch control circuit. Among them, the first input and output terminal A is connected to the third input and output terminal C through the first switch circuit 102, and the first switch circuit 102 is used to control the on-off between the first input and output terminal A and the third input and output terminal C. The second input and output terminal B is connected to the third input and output terminal C through the second switch circuit 101, and the second switch circuit 101 is used to control the on-off between the second input and output terminal and the third input and output terminal. The switch control circuit is connected to the first input and output terminal A, the second input and output terminal B, the first switch circuit 102 and the second switch circuit 101 respectively. The control circuit is used to turn on the first switch circuit 102 or the second switch circuit 101 under the triggering of the power signal when the first input and output terminal A or the second input and output terminal B is connected to the power supply, so that the power signal is output from the third input and output terminal C, so that when any charging interface is connected to the power supply, the electronic device can be charged. Or when the first input-output terminal A and the second input-output terminal B are connected with power signals at the same time, the first switch circuit 102 is controlled to be turned on and the second switch circuit 101 is turned off, so that the power signal of the first input-output terminal A is preferentially output from the third input-output terminal C to charge the electronic device, wherein the second switch circuit 101 is controlled to be turned off to prevent the current from flowing back due to the difference in voltage when the first input-output terminal A and the second input-output terminal B are charged at the same time, thereby affecting the charging efficiency. Through the circuit of this embodiment, the electronic device can be provided with two charging interfaces at the same time to meet the needs of special groups of people or personnel in special positions.

[0032] Furthermore, the control circuit is also used to receive a control signal sent by the main control unit when a power signal is connected to the third input-output terminal C, and control the on-off of the first switch circuit 102 and the second switch circuit 101, so that the power signal is output from the first input-output terminal A or the second input-output terminal B. Specifically, when in use, for example, when the main control unit detects that a device that needs to be charged is connected to the first input-output terminal A, a control signal is sent to the control circuit to control the first switch circuit 102 connected to the first input-output terminal A to be turned on, so that the power signal is output from the first input-output terminal A to charge the external device, or when the main control unit detects that a device that needs to be charged is connected to the second input-output terminal B, a control signal is sent to the control circuit to control the second switch circuit 101 connected to the second input-output terminal B to be turned on, so that the power signal is output from the second input-output terminal B to charge the external device. At the same time, in order to ensure the charging effect of the external device, when one terminal is charging, the other terminal is controlled to be turned off. For example, when the first switch circuit 102 connected to the first input-output terminal A is controlled to be turned on, so that the power signal is output from the first input-output terminal A, when the external device is charging, the second switch circuit 101 is controlled to be turned off.

[0033] The switch control circuit includes a first switch control circuit 104 and a second switch control circuit 103. The input end of the first switch control circuit 104 is connected to the first input-output end A, and the output end thereof is connected to the control end of the first switch circuit 102, and is used to control the first switch circuit 102 to be turned on under the triggering of the power signal connected to the first input-output end A, so that the power signal is output from the third input-output end C. The input end of the second switch control circuit 103 is connected to the second input-output end, and the output end thereof is connected to the control end of the second switch circuit 101, and is used to control the second switch circuit 101 to be turned on under the triggering of the power signal connected to the second input-output end, so that the power signal is output from the third input-output end C.

[0034] Further, the circuit also includes a third switch control circuit, the input end of which is connected to the output end of the first switch control circuit 104, and the input end of which is connected to the input end of the second switch control circuit 103, and is used to control the first switch circuit 104 to be turned on and the second switch circuit 103 to be turned off when the power signal is connected to the first input-output terminal and the second input-output terminal at the same time, so that the power signal of the first input-output terminal A is preferentially output from the third input-output terminal C. The third switch control circuit is a wire, one end of which is connected to the second electrode of the fifth transistor Q5, and the other end is connected to the control electrode of the third transistor Q3, that is, the output end of the first switch control circuit 104 is connected to the input end of the second switch control circuit 103, and is used to control the first switch circuit 102 to be turned on and the second switch circuit 101 to be turned off when the power signal is connected to the first input-output terminal A and the second input-output terminal B at the same time, so that the power signal of the first input-output terminal is preferentially output from the third input-output terminal A.

[0035] Furthermore, the first switch control circuit 104 further includes a first switch control terminal, such as Figure 1 The second switch control circuit 103 further includes a second switch control terminal, such as Figure 1 When a power signal is connected to the third input / output terminal, the first switch control terminal GPIO1 receives a high or low voltage control signal from the main control unit, so that the first switch circuit 102 is turned on, so that the power signal is output from the first input / output terminal A, or when a power signal is connected to the third input / output terminal C, the second switch control terminal B receives a control signal, so that the second switch circuit 101 is turned on, so that the power signal is output from the second input / output terminal B.

[0036] Specifically, Figure 1 The first switch control circuit 104 of this embodiment includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fourth transistor Q4, and a fifth transistor Q5. One end of the second resistor R2 is connected to the first input-output terminal A, and the other end is grounded; the control electrode of the fifth transistor Q5 is connected to the first input-output terminal A, the first electrode is grounded, and the second electrode is connected to the control end of the first switch circuit 102. The second electrode of the fourth transistor Q4 is also connected to the control end of the first switch circuit 102, the first electrode is grounded, and its control electrode is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the first switch control terminal GPIO1 for receiving the control signal of the main control chip; one end of the fourth resistor R4 is connected to the control electrode of the fourth transistor Q4, and the other end is grounded.

[0037] The second switch control circuit 103 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a first capacitor C1, a third transistor Q3 and a seventh transistor Q7. One end of the ninth resistor R9 is connected to the second input-output terminal B, and the other end is connected to the control electrode of the third transistor Q3. The first electrode of the third transistor Q3 is grounded, and the second electrode is connected to the control terminal of the second switch circuit 101. The first electrode of the seventh transistor Q7 is grounded, and the second electrode is also connected to the control terminal of the second switch circuit 101. Its control electrode is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is connected to the second switch control terminal GPIO2 for receiving a control signal; one end of the seventh resistor R7 is connected to the control electrode of the seventh transistor Q7, and the other end is grounded; one end of the eighth resistor R8 is connected to the control electrode of the third transistor Q3, and the other end is grounded; one end of the first capacitor C1 is connected to the control electrode of the third transistor Q3, and the other end is grounded. The first capacitor C1 plays a filtering role. In other embodiments, the first capacitor C1 may not be provided; the second electrode of the fifth transistor Q5 is also connected to one end of the ninth resistor R9.

[0038] Furthermore, the circuit of this embodiment further includes a fourth switch control circuit, the two ends of which are respectively connected to the first input-output terminal A and the second input-output terminal B, and are used to control the second switch circuit 101 to be preferentially turned on when the first input-output terminal A and the second input-output terminal B are simultaneously connected with power supply signals. The fourth switch control circuit includes a tenth resistor R10, an eleventh resistor R11, and a sixth transistor Q6, one end of the tenth resistor R10 is connected to the second input-output terminal B, and the other end is connected to the control electrode of the sixth transistor Q6, the first electrode of the sixth transistor Q6 is grounded, and the second electrode is connected to the first input-output terminal; one end of the eleventh resistor R11 is connected to the control electrode of the sixth transistor Q6, and the other end is grounded.

[0039] Among them, the fourth switch control circuit can be selected according to user needs. When the detection circuit does not include the fourth switch control circuit, when the A terminal and the B terminal are connected to the power signal at the same time, the first switch circuit 102 is preferentially turned on, and the specific conduction process is: the fifth transistor Q5 will be turned on to pull down the gate voltage of Q2, and Q2 will be turned on. When the fifth transistor Q5 is turned on, its collector is at a low level, and at this time, the base of Q3 is turned off due to the low level of the third transistor Q3. Then Q1 is turned off, the path from the B terminal to the C terminal is disconnected, and the A terminal to the C terminal is turned on.

[0040] When the detection circuit includes the fourth switch control circuit, that is, Figure 1In the circuit diagram shown, when the A terminal and the B terminal are connected to the power signal at the same time, the base of Q3 is at a high level, so the third transistor Q3 is turned on, the gate voltage of Q1 is pulled down, and Q1 is turned on. At this time, the sixth transistor Q6 is turned on, and the base of the fifth transistor Q5 is at a low level, so Q5 is not turned on, and therefore Q2 is not turned on. In addition, when the fourth switch control circuit is included, the one connected first between the B terminal and the C terminal is turned on first, and the conduction process is the same as above.

[0041] Among them, the transistors Q3, Q4, Q5, Q6, and Q7 of this embodiment can choose to use N-MOS or triodes according to the circuit current requirements; in this embodiment, NPN-type triodes are used, which include an emitter e, a base b, and a collector c, wherein the first electrode of the above-mentioned transistors Q3, Q4, Q5, Q6, and Q7 in this embodiment is the emitter e, the second electrode is the collector c, and the control collector is the base b.

[0042] Among them, the first switch circuit 102 and the second switch circuit 101 of this embodiment are both transistor switch circuits, which can be turned on and off under the triggering of a level signal. The transistor switch circuit includes at least one transistor, and the transistor switch circuit includes a first end, a second end and a control end. The first end and the second end of the first switch circuit 102 are respectively connected to the first input-output end and the third input-output end, and its control end is connected to the switch control circuit. The first end and the second end of the second switch circuit 101 are respectively connected to the first input-output end and the third input-output end, and its control end is connected to the switch control circuit.

[0043] Among them, the first switch circuit 102 and the second switch circuit 101 can use two P-MOS tubes separately according to the power demand of the power supply, or can use an integrated P-MOS tube type. For example, in this embodiment, the first switch circuit 102 includes a transistor A and a transistor B, the first electrode S1 of the transistor A is connected to the first electrode S2 of the transistor B, the second electrode D1 of the transistor A is the first end of the transistor circuit, which is used to connect to the first input-output terminal A, the second electrode D2 of the transistor B is the second end of the transistor circuit, which is used to connect to the third input-output terminal C, the control electrode G1 of the transistor A is connected to the control electrode G2 of the transistor B, which is the control end of the transistor circuit, the first electrode S1 of the transistor A is connected to the first electrode S2 of the transistor B, and then connected in series with the fifth resistor R5, and then connected to the output end of the first switch control circuit 104, as shown in the specific example. Figure 1 The output end of the first switch control circuit 104 is the collector c of the fourth transistor Q4 and the fifth transistor Q5, and the control end is connected to the output end of the switch control circuit.

[0044] The structure and connection method of the second switch circuit 101 are the same as those of the first switch circuit 102, and will not be described in detail here. The first switch circuit 102 and the second switch circuit 101 use existing integrated P-MOS transistors. For ease of understanding, the first switch circuit 102 can be understood as a transistor Q2, and the second switch circuit 101 can be understood as a first transistor Q1.

[0045] In addition, the circuit also includes a first resistor R1, a twelfth resistor R12 and a thirteenth resistor R13, one end of the first resistor R1 is connected to the first input-output terminal A, and the other end is connected to the control electrode of the fifth transistor Q5, one end of the twelfth resistor R12 is connected to the second electrode of the third transistor Q3, and the other end is connected to the input end of the second switching circuit 101; one end of the thirteenth resistor R13 is connected to the second input-output terminal B, and the other end is connected to one end of the ninth resistor R9.

[0046] The circuit of this embodiment is described below according to different working modes.

[0047] 1. When the first input-output terminal A has power input alone, and the second input-output terminal B and the third input-output terminal C have no power input, the fifth transistor Q5 is turned on, and the gate voltage of the second transistor Q2 is pulled down, and the second transistor Q2 is turned on. At this time, the power of the first input-output terminal A can be output to the third input-output terminal C. When the fifth transistor Q5 is turned on, its collector is at a low level, and the base voltage of the third transistor Q3 is pulled down, and Q3 is not turned on. Since the first transistor Q1 MOS tube is a Schottky diode, Q1 (B terminal to C terminal) is in a cut-off state at this time, so the second switch circuit 101 is in a disconnected state.

[0048] 2. When the second input-output terminal B has power input alone, the third transistor Q3 is turned on, the gate voltage of Q1 is pulled down, and Q1 is turned on. The power supply of the second input-output terminal B is input to the third input-output terminal C. At this time, since the second input-output terminal B is at a high level, Q2 is turned off, and the first switch circuit 102 is in an off state.

[0049] 3. When the fourth switch control circuit is not included, when the first input / output terminal A and the second input / output terminal B have power input at the same time, the fifth transistor Q5 will be turned on to pull down the gate voltage of Q2, and Q2 will be turned on. When the second transistor Q2 is turned on, the collector of the fifth transistor Q5 is at a low level, and at this time, the base of Q3 is turned off due to the low level. Then Q1 is turned off, the path from terminal B to terminal C is disconnected, and terminal A to terminal C is turned on.

[0050] 5. When the fourth switch control circuit is included, when the A terminal and the B terminal are connected to the power signal at the same time, the control electrode of Q3 is at a high level, so the third transistor Q3 is turned on, the gate voltage of Q1 is pulled down, and Q1 is turned on. At this time, the sixth transistor Q6 is turned on, and the base of the fifth transistor Q5 is at a low level, so Q5 is not turned on, and therefore Q2 is also not turned on.

[0051] 4. When the power is supplied to the C terminal and outputted to the A terminal, the first switch control terminal GPIO1 receives the control signal (high level) sent by the main control chip to turn on the fourth transistor Q4 and the second transistor Q2. The C terminal to the A terminal is normally turned on. Since the third transistor Q3 is not turned on, Q1 is not turned on. The C terminal to the B terminal is disconnected.

[0052] 5. When the third input-output terminal C has power to be output to the B terminal, the second switch control terminal GPIO2 receives a control signal (high level) to turn on the seventh transistor Q7 and Q1. The C terminal to the B terminal is normally connected. Since Q2 is not turned on, the C terminal to the A terminal is disconnected.

[0053] Through the above analysis, it can be known that the three-terminal power input and output switching circuit of this embodiment can realize charging by selecting one of the two input terminals when charging, and the first connected first turned on when the two-terminal power input is used, and when the electronic product is used to charge the external device, the output terminal can be charged by selecting one of the two output terminals. This can meet the charging and discharging requirements of the dual charging and discharging interfaces of some electronic products.

[0054] Embodiment 2:

[0055] This embodiment provides a three-terminal power input and output switching device, which includes the three-terminal power input and output switching circuit provided in the above embodiment 1, and also includes three input and output interfaces, which are respectively connected to the first input and output terminal A, the second input and output terminal B, and the third input and output terminal C. Through this device, it is possible to realize charging of two input terminals in a one-to-one manner, and when the two-terminal power input is connected first, it is possible to realize charging of two output terminals in a one-to-one manner when the electronic product is used to charge the external device. This can meet the charging and discharging requirements of the dual charging and discharging interfaces of some electronic products.

[0056] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A three-terminal power input and output switching circuit, characterized in that: It includes a first input-output terminal, a second input-output terminal, a third input-output terminal, a first switch circuit, a second switch circuit and a switch control circuit; The first input / output terminal is connected to the third input / output terminal through a first switch circuit, the first switch circuit is used to control the on / off between the first input / output terminal and the third input / output terminal, and the second input / output terminal is connected to the third input / output terminal through a second switch circuit, the second switch circuit is used to control the on / off between the second input / output terminal and the third input / output terminal; The switch control circuit is connected to the first input / output terminal, the second input / output terminal, the first switch circuit and the second switch circuit respectively; The control circuit is used for, when a power signal is connected to the first input / output terminal or the second input / output terminal, to turn on the first switch circuit or the second switch circuit under the triggering of the power signal, so that the power signal is output from the third input / output terminal; and when a power signal is connected to both the first input / output terminal and the second input / output terminal at the same time, to control the first switch circuit to turn on and the second switch circuit to turn off, so that the power signal of the first input / output terminal is preferentially output from the third input / output terminal; The control circuit is further used to receive a control signal when a power signal is connected to the third input / output terminal, and control the on / off of the first switch circuit and the second switch circuit, so that the power signal is output from the first input / output terminal or the second input / output terminal; The switch control circuit includes a first switch control circuit and a second switch control circuit; The input end of the first switch control circuit is connected to the first input-output end, and the output end thereof is connected to the control end of the first switch circuit, and is used to control the first switch circuit to be turned on under the triggering of the power signal connected to the first input-output end, so that the power signal is output from the third input-output end; The input end of the second switch control circuit is connected to the second input-output end, and the output end thereof is connected to the control end of the second switch circuit, and is used to control the second switch circuit to be turned on under the triggering of the power signal connected to the second input-output end, so that the power signal is output from the third input-output end; The three-terminal power input and output switching circuit also includes a third switch control circuit; The input end of the third switch control circuit is connected to the output end of the first switch control circuit, and the input end thereof is connected to the input end of the second switch control circuit, and is used to control the first switch circuit to be turned on and the second switch circuit to be turned off when the first input / output end and the second input / output end are connected with power signals at the same time, so that the power signal of the first input / output end is outputted from the third input / output end first; The first switch control circuit further includes a first switch control terminal, and the second switch control circuit further includes a second switch control terminal; When a power signal is connected to the third input / output terminal, the first switch control terminal receives a control signal to turn on the first switch circuit, thereby outputting the power signal from the first input / output terminal; or when a power signal is connected to the third input / output terminal, the second switch control terminal receives a control signal to turn on the second switch circuit, thereby outputting the power signal from the second input / output terminal; The first switch control circuit includes a second resistor, a third resistor, a fourth resistor, a fourth transistor, and a fifth transistor, wherein one end of the second resistor is connected to the first input / output end, and the other end is grounded; the control electrode of the fifth transistor is connected to the first input / output end, the first electrode is grounded, and the second electrode is connected to the control end of the first switch circuit; the first electrode of the fourth transistor is grounded, the second electrode is also connected to the control end of the first switch circuit, and the control electrode is connected to one end of the third resistor, and the other end of the third resistor is connected to the first switch control end, for receiving a control signal; One end of the fourth resistor is connected to the control electrode of the fourth transistor, and the other end is grounded; The second switch control circuit includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third transistor and a seventh transistor, one end of the ninth resistor is connected to the second input-output end, and the other end is connected to the control electrode of the third transistor, a first electrode of the third transistor is grounded, and a second electrode is connected to the control end of the second switch circuit, a first electrode of the seventh transistor is grounded, and a second electrode is also connected to the control end of the second switch circuit, and its control electrode is connected to one end of the sixth resistor, and the other end of the sixth resistor is connected to the second switch control end for receiving a control signal; One end of the seventh resistor is connected to the control electrode of the seventh transistor, and the other end is grounded; one end of the eighth resistor is connected to the control electrode of the third transistor, and the other end is grounded; The third switch control circuit is a wire, one end of which is connected to the second electrode of the fifth transistor, and the other end of which is connected to the control electrode of the third transistor.

2. The three-terminal power input and output switching circuit according to claim 1, characterized in that: The first switch circuit and the second switch circuit are both transistor switch circuits, which include at least one transistor; the transistor switch circuits include a first end, a second end and a control end, the first end and the second end are respectively connected to the first input-output end and the third input-output end, and the control end is connected to the switch control circuit, or the first end and the second end are respectively connected to the first input-output end and the third input-output end, and the control end is connected to the switch control circuit.

3. The three-terminal power input and output switching circuit as claimed in claim 2, characterized in that: The transistor switch circuit includes a transistor A and a transistor B, wherein the first electrode of the transistor A is connected to the first electrode of the transistor B, the second electrode of the transistor A is the first end of the transistor switch circuit, the second electrode of the transistor B is the second end of the transistor switch circuit, and the control electrode of the transistor A and the control electrode of the transistor B are connected to serve as the control end of the transistor switch circuit.

4. The three-terminal power input and output switching circuit according to claim 1, characterized in that: It also includes a fourth switch control circuit, wherein two ends of the fourth switch control circuit are respectively connected to the first input / output end and the second input / output end, and is used to control the second switch circuit to be turned on preferentially when the first input / output end and the second input / output end are simultaneously connected with power signals; The fourth switch control circuit includes a tenth resistor, an eleventh resistor and a sixth transistor, one end of the tenth resistor is connected to the second input-output terminal, and the other end is connected to the control electrode of the sixth transistor, the first electrode of the sixth transistor is grounded, and the second electrode is connected to the first input-output terminal; one end of the eleventh resistor is connected to the control electrode of the sixth transistor, and the other end is grounded.

5. A three-terminal power input and output switching device, characterized in that: A three-terminal power input and output switching circuit comprising any one of claims 1 to 4; It also includes three input and output interfaces, which are respectively connected to the first input and output end, the second input and output end, and the third input and output end.

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