A multi-power supply switching circuit

Abstract

The utility model discloses a kind of multi-power supply switching circuit, including programmable circuit, reference voltage circuit, comparison circuit, switching circuit;Comparison circuit is used to monitor each power supply voltage, and when current power supply voltage drops to specified value, output signal to programmable circuit;Switching circuit switches to different power supply for power supply according to the control signal of programmable circuit;Programmable circuit is used to select output signal control corresponding power supply according to the priority of power supply;Switching circuit includes switch tube circuit, anti-backflow circuit;Switch tube circuit is used to switch according to the control signal of programmable circuit, and anti-backflow circuit is used to prevent current backflow in power supply process.Avoid simultaneously opening two different power supply, by setting N-type switch tube circuit in switching circuit, it is favorable to reduce power consumption, by setting anti-backflow circuit, it is favorable to prevent current backflow in power supply process.

Description

Technical Field

[0001] This utility model relates to the field of multi-power supply circuit switching technology, and in particular to a multi-power supply switching circuit. Background Technology

[0002] Currently, in the field of circuit design, two types of circuits are commonly used for circuit systems powered by multiple power sources: 1. Using diodes to separate different power sources. This circuit is simple and can avoid the problem of current backflow between different power sources, but it cannot avoid the losses of the diodes themselves; 2. Using dual PMOS to separate different power sources, and then using the MCU's I / O port to control the switching of the MOS. This circuit can effectively avoid the diode loss problem of the above circuit, but if the MCU program is written incorrectly and two MOS of different power sources are turned on at the same time, the problem of current backflow will occur. Utility Model Content

[0003] In existing technologies, diode losses and reverse current flow problems exist in multi-power supply circuit systems.

[0004] To address the aforementioned issues, a multi-power supply switching circuit is proposed. By utilizing a programmable circuit to select the corresponding power supply based on its priority, the circuit controls the switching of the appropriate power supply, avoiding the simultaneous switching of two different power supplies. By incorporating an N-type switching transistor circuit in the switching circuit, the circuit helps prevent the MOSFET from failing to turn off completely, thus reducing power consumption. Furthermore, the inclusion of an anti-backflow circuit helps prevent current backflow during power supply.

[0005] A multi-power supply switching circuit includes: Programmable circuits; Reference voltage circuit; Comparator circuit; Switching circuit; The reference voltage circuit, the comparator circuit, and the switching circuit are all electrically connected to the programmable circuit. The reference voltage circuit is also electrically connected to the comparator circuit, and is used to provide a reference voltage to the comparator circuit; The comparison circuit is used to monitor the voltage of each power supply and output a signal to the programmable circuit when the current power supply voltage drops to a specified value. The switching circuit switches to different power supplies according to the control signal from the programmable circuit. The programmable circuit is used to select the output signal to control the switching of the corresponding power supply according to the priority of the power supply. The switching circuit includes: Switching transistor circuit; Anti-backflow circuit; The switching transistor circuit is electrically connected to the anti-backflow circuit; The switching transistor circuit is used to switch on and off according to the control signal of the programmable circuit, and the anti-backflow circuit is used to prevent current backflow during power supply.

[0006] In conjunction with the first possible embodiment of this utility model, and in the second possible embodiment, the switching transistor circuit includes: NMOS transistor; First resistor and second resistor; The first end of the first resistor is electrically connected to the programmable circuit, and the second end of the first resistor is electrically connected to the first end of the second resistor and the gate of the NMOS transistor. The source of the NMOS transistor and the second terminal of the second resistor are both connected to ground; The drain of the NMOS transistor is electrically connected to the backflow prevention circuit.

[0007] In conjunction with the second possible embodiment of this utility model, and in the third possible embodiment, the anti-backflow circuit includes: First PMOS transistor and second PMOS transistor; Third resistor; The gates of the first PMOS transistor and the second PMOS transistor, and the first terminal of the third resistor are connected together and then electrically connected to the drain of the NMOS transistor. The drain of the first PMOS transistor is electrically connected to the power supply. The source of the first PMOS transistor, the second end of the third resistor, and the source of the second PMOS transistor are connected together. The drain of the second PMOS transistor is electrically connected to the output circuit.

[0008] In conjunction with the third possible embodiment of this utility model, and in the fourth possible embodiment, the switching circuit further includes: Output circuit; The output circuit is electrically connected to the switching transistor circuit and the anti-backflow circuit, respectively.

[0009] In conjunction with the fourth and fifth possible embodiments of this utility model, the output circuit includes: First capacitor; The first terminal of the first capacitor is connected to ground along with the source of the NMOS transistor and the second terminal of the second resistor; The second terminal of the first capacitor is electrically connected to the drain of the second PMOS transistor.

[0010] In conjunction with the multi-power supply switching circuit described in this utility model, in a sixth possible embodiment, the comparison circuit includes: Power supply voltage input circuit; Reference voltage input circuit; Comparator chip; Power supply circuit; The power supply voltage input circuit is electrically connected to the negative input pin of the comparator chip, and the reference voltage input circuit is electrically connected to the positive input pin of the comparator chip. The power supply circuit is electrically connected to the power supply pin of the comparator chip and is used to supply power to the comparator circuit. The power supply voltage input circuit, the reference voltage input circuit, and the power supply circuit are also connected to the ground pin of the comparator chip and then grounded.

[0011] In conjunction with the sixth and seventh possible embodiments of this utility model, the power supply voltage input circuit includes: The fourth and fifth resistors; The first end of the fourth resistor is electrically connected to the power supply, and the second end of the fourth resistor is electrically connected to the negative input pin of the comparator chip and the first end of the fifth resistor. The second terminal of the fifth resistor is grounded.

[0012] In conjunction with the sixth possible embodiment of this utility model, and the eighth possible embodiment, the reference voltage input circuit includes: The sixth and seventh resistors; The first end of the sixth resistor is electrically connected to the reference power supply, and the second end of the sixth resistor is electrically connected to the positive input pin of the comparator chip and the first end of the seventh resistor. The second terminal of the seventh resistor is grounded.

[0013] In conjunction with the sixth and ninth possible embodiments of this utility model, the power supply circuit includes: The second capacitor and the third capacitor; The first terminals of the second and third capacitors are electrically connected to the power supply pins and power supply of the comparator chip, and the second terminals of the second and third capacitors are grounded.

[0014] In the tenth possible embodiment of the multi-power supply switching circuit described in this utility model, the number of power supplies is multiple; correspondingly, the number of comparison circuits and switching circuits is also multiple, and the power supplies, switching circuits, and comparison circuits correspond one-to-one.

[0015] The multi-power supply switching circuit described in this utility model utilizes a programmable circuit to select the output signal to control the switching of the corresponding power supply according to the priority of the power supply, avoiding the simultaneous switching of two different power supplies. By setting an N-type switching transistor circuit in the switching circuit, it is beneficial to avoid the MOSFET from being unable to be completely turned off, thus reducing power consumption. The anti-backflow circuit helps to prevent current backflow during the power supply process. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 The logic circuit diagram of the multi-power supply switching circuit in this utility model is shown below. Figure 2 The circuit diagram of the programmable circuit in the multi-power supply switching circuit of this utility model is shown. Figure 3 This is a circuit diagram of the first switching circuit corresponding to the first power supply in the multi-power supply switching circuit of this utility model. Figure 4 This is a circuit diagram of the second switching circuit corresponding to the second power supply in the multi-power supply switching circuit of this utility model. Figure 5 This is a circuit diagram of the third switching circuit corresponding to the third power supply in the multi-power supply switching circuit of this utility model. Figure 6 This is a circuit diagram of the first comparison circuit corresponding to the first power supply in the multi-power supply switching circuit of this utility model. Figure 7 This is a circuit diagram of the second comparison circuit corresponding to the second power supply in the multi-power supply switching circuit of this utility model. Figure 8 This is a circuit diagram of the third comparison circuit corresponding to the third power supply in the multi-power supply switching circuit of this utility model. Figure 9 The circuit diagram of the reference voltage circuit in the multi-power supply switching circuit of this utility model is shown. Figure 10 This is a truth table diagram of the multi-power supply switching circuit in this utility model.

[0018] Components and their serial numbers: 110 – Programmable circuit, 120 – Power supply, 130 – Switching circuit, 140 – Comparison circuit, 150 – Reference voltage circuit. Detailed Implementation

[0019] The technical solutions of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, other embodiments obtained by those skilled in the art without creative effort are all within the scope of protection of this utility model.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0022] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0024] In existing technologies, diode losses and reverse current flow problems exist in multi-power supply circuit systems.

[0025] To address the above problems, a multi-power supply switching circuit is proposed.

[0026] A multi-power supply switching circuit, such as Figure 1 , Figure 1 The logic circuit diagram of the multi-power supply switching circuit in this utility model includes a programmable circuit 110, a reference voltage circuit 150, a comparator circuit 140, and a switching circuit 130. The reference voltage circuit 150, comparator circuit 140, and switching circuit 130 are electrically connected to the programmable circuit 110. The reference voltage circuit 150 is also electrically connected to the comparator circuit 140 to provide a reference voltage to the comparator circuit 140. The comparator circuit 140 monitors the voltage of each power supply 120 and outputs signals (POWER_SINGAL_1, POWER_SINGAL_2, POWER_SINGAL_3) to the programmable circuit 110 when the voltage of the current power supply 120 drops to a specified value. POWER_SINGAL_3; The switching circuit 130 switches to different power supplies 120 for power supply according to the control signal of the programmable circuit 110; the programmable circuit 110 is used to select the output signal of the power supply 120 according to the priority of the power supply 120 to control the switching of the corresponding power supply 120; wherein, the switching circuit 130 includes a switching transistor circuit and an anti-backflow circuit; the switching transistor circuit and the anti-backflow circuit are electrically connected; the switching transistor circuit is used to switch according to the control signal of the programmable circuit 110, and the anti-backflow circuit is used to prevent current backflow during the power supply process.

[0027] In the embodiments of this application, such as Figure 10 , Figure 10 The truth table diagram of the multi-power supply switching circuit in this utility model is shown. The three power supplies are electrically connected to the selection signal pins (A, B, C) and enable pins (G1, G2A, G2B) of the programmable decoder. According to the power supply priority and the decoder (taking 74HC138 as an example), the appropriate output signal is selected through the output pins (Y0-Y6) to control the on / off state of the MOS transistors of the corresponding switching power. This can realize hardware coding to control the on / off state of the MOS transistors and ensure that only one power supply can be turned on at the same time, thus avoiding backflow in the circuit.

[0028] In this embodiment, as Figure 2 , Figure 2 This is a circuit schematic diagram of the programmable circuit 110 in the multi-power supply switching circuit of this utility model; Figure 2In this circuit, each comparator circuit 140 and reference voltage circuit 150 are electrically connected to the programmable circuit 110 via VCC_SWITCH. Reference voltage circuit 150 outputs a reference voltage of 1.2V to each comparator circuit 140. Each comparator circuit 140 is also electrically connected to the programmable circuit 110 via POWER_A, POWER_B, and POWER_C. Figure 3-5 Each switching circuit 130 is electrically connected to the programmable circuit 110 via POWER_A, POWER_B, POWER_C and POWER_SWITCH_1, POWER_SWITCH_2, POWER_SWITCH_3, respectively. The programmable circuit 110 is used to select the output signal to control the switching of the corresponding power supply 120 according to its priority, avoiding the simultaneous switching of two different power supplies. The inclusion of an N-type switching transistor in the switching circuit 130 helps prevent the MOSFET from failing to completely turn off, reducing power consumption. Furthermore, the inclusion of an anti-reverse current circuit helps prevent current backflow during power supply.

[0029] In one specific implementation, such as Figure 3-5 , Figure 3 This is a circuit diagram of the first switching circuit corresponding to the first power supply 120 in the multi-power supply switching circuit of this utility model. Figure 4 This is a circuit diagram of the second switching circuit corresponding to the second power supply 120 in the multi-power supply switching circuit of this utility model. Figure 5 This is a circuit diagram of the third switching circuit 130 corresponding to the third power supply 120 in the multi-power supply switching circuit of this utility model. In this embodiment, there are three power supplies 120, namely POWER_A, POWER_B, and POWER_C, and there are also three corresponding switching circuits 130 and comparator circuits 140. The circuit structures of each switching circuit 130 and comparator circuit 140 are the same. Taking the first switching circuit of the first power supply 120 as an example, the switching transistor circuit includes an NMOS transistor Q7, a first resistor R4, and a second resistor R7. The first end of the first resistor R4 is electrically connected to the programmable circuit 110, and the second end of the first resistor R4 is electrically connected to the first end of the second resistor R7 and the gate of the NMOS transistor Q7. The source of the NMOS transistor and the second end of the second resistor R7 are grounded together. The drain of the NMOS transistor Q7 is electrically connected to the anti-backflow circuit.

[0030] In one specific implementation, such as Figure 3-5Taking the first switching circuit 130 of the first power supply 120 as an example, the anti-backflow circuit includes a first PMOS transistor Q1, a second PMOS transistor Q2, and a third resistor R1; the gates of the first PMOS transistor Q1 and the second PMOS transistor Q2, and the first end of the third resistor R1 are connected together and then electrically connected to the drain of the NMOS transistor Q7; the drain of the first PMOS transistor Q1 is electrically connected to the power supply 120, the source of the first PMOS transistor Q1, the second end of the third resistor R1, and the source of the second PMOS transistor Q2 are connected together, and the drain of the second PMOS transistor Q2 is electrically connected to the output circuit.

[0031] In one specific embodiment, taking the first switching circuit of the first power supply 120 as an example, the switching circuit 130 further includes an output circuit; the output circuit is electrically connected to the switching transistor circuit and the anti-backflow circuit respectively.

[0032] In one specific embodiment, taking the first switching circuit of the first power supply 120 as an example, the output circuit includes a first capacitor C1; the first end of the first capacitor C1 is connected to the source of the NMOS transistor Q7 and the second end of the second resistor R7, and the second end of the first capacitor C1 is electrically connected to the drain of the second PMOS transistor Q2.

[0033] In one specific implementation, such as Figure 6-8 , Figure 6 This is a circuit diagram of the first comparator circuit 140 corresponding to the first power supply 120 in the multi-power supply switching circuit of this utility model. Figure 7 This is a circuit diagram of the second comparator circuit 140 corresponding to the second power supply 120 in the multi-power supply switching circuit of this utility model. Figure 8 This is a circuit diagram of the third comparator circuit 140 corresponding to the third power supply 120 in the multi-power supply switching circuit of this utility model.

[0034] In this embodiment, each switch corresponds to a comparator circuit 140. The circuit structures of the comparator circuits 140 are the same. Taking the first comparator circuit 140 as an example, the comparator circuit 140 includes a power supply voltage input circuit 120, a reference voltage input circuit, a comparator chip U3, and a power supply circuit. The power supply voltage input circuit 120 is electrically connected to the negative input pin of the comparator chip U3, and the reference voltage input circuit is electrically connected to the positive input pin of the comparator chip U3. The power supply circuit is electrically connected to the power supply pin of the comparator chip U3 and is used to supply power to the comparator circuit 140. The power supply voltage input circuit 120, the reference voltage input circuit, and the power supply circuit are also connected to the ground pin of the comparator chip U3 and then grounded.

[0035] In one specific embodiment, taking the first comparator circuit 140 as an example, the voltage input circuit of the power supply 120 includes a fourth resistor R14 and a fifth resistor R20; the first end of the fourth resistor R14 is electrically connected to the power supply 120, the second end of the fourth resistor R14 is electrically connected to the negative input pin of the comparator chip U3 and the first end of the fifth resistor R20; the second end of the fifth resistor R20 is grounded.

[0036] In one specific embodiment, taking the first comparator circuit 140 as an example, the reference voltage input circuit includes a sixth resistor R15 and a seventh resistor R21; the first end of the sixth resistor R15 is electrically connected to the reference power supply VCC_1.2V, the second end of the sixth resistor R15 is electrically connected to the positive input pin of the comparator chip U3 and the first end of the seventh resistor R21; the second end of the seventh resistor R21 is grounded.

[0037] In one specific embodiment, the power supply circuit includes a second capacitor C10 and a third capacitor C11; the first terminals of the second capacitor C10 and the third capacitor C11 are electrically connected to the power supply pins VS and VCC_SWITCH of the comparator chip U3, and the second terminals of the second capacitor C10 and the third capacitor C11 are grounded.

[0038] like Figure 9 , Figure 9 This is a circuit diagram of the reference voltage circuit 150 in the multi-power supply switching circuit of this utility model; the circuit structure of the reference voltage circuit 150 is as follows. Figure 9 As shown, it includes a voltage chip U4 and two filter circuits that are electrically connected.

[0039] In one specific embodiment, there are multiple power supply 120s; correspondingly, there are also multiple comparator circuits 140 and switch circuits 130, with each power supply 120, switch circuit 130, and comparator circuit 140 corresponding to the other.

[0040] The multi-power supply switching circuit of this utility model utilizes a programmable circuit 110 to select the output signal of the power supply 120 according to its priority to control the switching of the corresponding power supply 120, thus avoiding the simultaneous switching of two different power supplies. By setting an N-type switching transistor circuit in the switching circuit 130, it is beneficial to avoid the MOSFET from being unable to be completely turned off, thereby reducing power consumption. The anti-backflow circuit helps to prevent current backflow during power supply.

[0041] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A multi-power supply switching circuit, characterized in that it comprises: Programmable circuits; Reference voltage circuit; Comparator circuit; Switching circuit; The reference voltage circuit, the comparator circuit, and the switching circuit are all electrically connected to the programmable circuit. The reference voltage circuit is also electrically connected to the comparator circuit, and is used to provide a reference voltage to the comparator circuit; The comparison circuit is used to monitor the voltage of each power supply and output a signal to the programmable circuit when the current power supply voltage drops to a specified value. The switching circuit switches to different power supplies according to the control signal from the programmable circuit. The programmable circuit is used to select the output signal to control the switching of the corresponding power supply according to the priority of the power supply. The switching circuit includes: Switching transistor circuit; Anti-backflow circuit; The switching transistor circuit is electrically connected to the anti-backflow circuit; The switching transistor circuit is used to switch on and off according to the control signal of the programmable circuit, and the anti-backflow circuit is used to prevent current backflow during power supply.

2. The multi-power supply switching circuit according to claim 1, characterized in that, The switching transistor circuit includes: NMOS transistor; First resistor and second resistor; The first end of the first resistor is electrically connected to the programmable circuit, and the second end of the first resistor is electrically connected to the first end of the second resistor and the gate of the NMOS transistor. The source of the NMOS transistor and the second terminal of the second resistor are both connected to ground; The drain of the NMOS transistor is electrically connected to the backflow prevention circuit.

3. The multi-power supply switching circuit according to claim 2, characterized in that, The backflow prevention circuit includes: First PMOS transistor and second PMOS transistor; Third resistor; The gates of the first PMOS transistor and the second PMOS transistor, and the first terminal of the third resistor are connected together and then electrically connected to the drain of the NMOS transistor. The drain of the first PMOS transistor is electrically connected to the power supply. The source of the first PMOS transistor, the second end of the third resistor, and the source of the second PMOS transistor are connected together. The drain of the second PMOS transistor is electrically connected to the output circuit.

4. The multi-power supply switching circuit according to claim 3, characterized in that, The switching circuit also includes: Output circuit; The output circuit is electrically connected to the switching transistor circuit and the anti-backflow circuit, respectively.

5. The multi-power supply switching circuit according to claim 4, characterized in that, The output circuit includes: First capacitor; The first terminal of the first capacitor is connected to ground along with the source of the NMOS transistor and the second terminal of the second resistor; The second terminal of the first capacitor is electrically connected to the drain of the second PMOS transistor.

6. The multi-power supply switching circuit according to claim 1, characterized in that, The comparison circuit includes: Power supply voltage input circuit; Reference voltage input circuit; Comparator chip; Power supply circuit; The power supply voltage input circuit is electrically connected to the negative input pin of the comparator chip, and the reference voltage input circuit is electrically connected to the positive input pin of the comparator chip. The power supply circuit is electrically connected to the power supply pin of the comparator chip and is used to supply power to the comparator circuit. The power supply voltage input circuit, the reference voltage input circuit, and the power supply circuit are also connected to the ground pin of the comparator chip and then grounded.

7. The multi-power supply switching circuit according to claim 6, characterized in that, The power supply voltage input circuit includes: The fourth and fifth resistors; The first end of the fourth resistor is electrically connected to the power supply, and the second end of the fourth resistor is electrically connected to the negative input pin of the comparator chip and the first end of the fifth resistor. The second terminal of the fifth resistor is grounded.

8. The multi-power supply switching circuit according to claim 6, characterized in that, The reference voltage input circuit includes: The sixth and seventh resistors; The first end of the sixth resistor is electrically connected to the reference power supply, and the second end of the sixth resistor is electrically connected to the positive input pin of the comparator chip and the first end of the seventh resistor. The second terminal of the seventh resistor is grounded.

9. The multi-power supply switching circuit according to claim 6, characterized in that, The power supply circuit includes: The second capacitor and the third capacitor; The first terminals of the second and third capacitors are electrically connected to the power supply pins and power supply of the comparator chip, and the second terminals of the second and third capacitors are grounded.

10. The multi-power supply switching circuit according to any one of claims 1-9, characterized in that, There are multiple power supplies; correspondingly, there are also multiple comparison circuits and switching circuits, with each power supply, switching circuit, and comparison circuit corresponding to the other.

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