Input switching circuit and wide range DC power supply device

Abstract

The present application relates to the field of electronic circuit technology, and discloses an input switching circuit and a wide-range DC power supply device, wherein the input switching circuit comprises: a power input terminal, a power output terminal and a switching module, wherein the switching module is configured to connect the power input terminal with the power output terminal when the power supply voltage of the DC power supply is less than the target voltage, so that the boost circuit performs a boost conversion on the DC power supply and outputs the target voltage; when the power supply voltage of the DC power supply is greater than the target voltage, the buck circuit performs a buck conversion on the DC power supply and outputs the target voltage, so that the power input terminal and the power output terminal are disconnected according to the target voltage. Thus, no external control signal is required, and the automatic switching to the boost or buck working mode can be realized based on the input voltage of different ranges, so that the circuit can be applied to a power supply environment with a wide voltage range, which increases its applicability and flexibility.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to an input switching circuit and a wide-range direct current power supply device. Background Art

[0002] A wide-range DC power supply device refers to a power supply device that can accept a wide input voltage range. This voltage input method can facilitate electronic products to work stably under conditions where the input voltage fluctuates. In electronic equipment and systems, it is very important for wide-range DC power supplies to adapt to wide-range DC voltage inputs with different voltage levels to ensure equipment reliability and flexibility. However, there are still limitations in the processing of wide-range DC voltage inputs in related technologies, and a more flexible method for adjusting the output voltage is needed. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the present application proposes an input switching circuit and a wide-range DC power supply device. The main technical solutions adopted in the present application include:

[0004] In a first aspect, an embodiment of the present application provides an input switching circuit, which is applied to a wide-range DC power supply device. The wide-range DC power supply device includes a boost circuit and a buck circuit. The input switching circuit includes:

[0005] A power input terminal, suitable for connecting a DC power supply and an input terminal of a step-down circuit;

[0006] A power output terminal, suitable for connecting to the input terminal of a boost circuit;

[0007] A switching module, wherein a first end of the switching module is connected to a power input end, a second end of the switching module is suitable for connecting to a power output end of a wide range DC power supply device, and a third end of the switching module is connected to a power output end. The switching module is configured as

[0008] When the supply voltage of the DC power supply is lower than the target voltage, the power supply input terminal is connected to the power supply output terminal so that the boost circuit performs a boost conversion on the DC power supply to output the target voltage;

[0009] When the supply voltage of the DC power supply is greater than the target voltage, the step-down circuit steps down the DC power supply and outputs the target voltage, so as to disconnect the power input terminal from the power output terminal according to the target voltage.

[0010] Optionally, the switching module includes:

[0011] A first switch control unit, wherein a first end of the first switch control unit is connected to a power input end, and a second end of the first switch control unit is connected to a power output end;

[0012] A second switch control unit, wherein a first end of the second switch control unit is connected to a power input end, a second end of the second switch control unit is suitable for connecting to a power supply output end of a wide range DC power supply device, an output end of the second switch control unit is connected to a control end of the first switch control unit, the second switch control unit is turned off when a power supply voltage of the DC power supply is less than a target voltage so that the first switch control unit is turned on, and is turned on when a power supply voltage of the DC power supply is greater than a target voltage so that the first switch control unit is turned off.

[0013] Optionally, the first switch control unit includes:

[0014] A first triode, the base of the first triode serves as a control terminal of the first switch control unit, and the collector of the first triode is connected to the power input terminal through a first resistor module;

[0015] a second resistor, one end of the second resistor being connected to the emitter of the first transistor;

[0016] The second triode has a base connected to the other end of the second resistor, a collector connected to the power input end, and an emitter connected to the power output end.

[0017] Optionally, the first resistor module includes a plurality of first resistors, and the plurality of first resistors are connected in parallel.

[0018] Optionally, the second switch control unit includes:

[0019] A first voltage regulator tube, wherein the cathode of the first voltage regulator tube is connected to the power supply output end of the wide-range DC power supply device;

[0020] A third resistor, one end of the third resistor is connected to the anode of the first voltage regulator tube;

[0021] a third triode, wherein the base of the third triode is connected to the other end of the third resistor, the emitter of the third triode is grounded, the collector of the third triode is connected to the power input end through the second resistor module, and the collector of the third triode serves as the output end of the second switch control unit;

[0022] A fourth resistor is connected between the base and the emitter of the third transistor.

[0023] Optionally, the second resistor module includes a plurality of fifth resistors, and the plurality of fifth resistors are connected in parallel.

[0024] Optionally, the switching module further includes:

[0025] A second voltage regulator tube, wherein the anode of the second voltage regulator tube is grounded, and the cathode of the second voltage regulator tube is respectively connected to the output end of the second switch control unit and the control end of the first switch control unit;

[0026] The first capacitor is connected in parallel with the second voltage regulator tube.

[0027] In a second aspect, an embodiment of the present application provides a wide-range DC power supply device, comprising:

[0028] Boost circuit and buck circuit;

[0029] The input switching circuit mentioned in the above embodiment switches the boost circuit and the buck circuit to work separately based on the input DC power supply voltage.

[0030] Optionally, the boost circuit comprises:

[0031] A boost inductor, one end of which is connected to the output end of the power supply;

[0032] A boost chip, wherein the input pin of the boost chip is connected to one end of the boost inductor, and the output pin of the boost chip is connected to the other end of the boost inductor;

[0033] a first diode, wherein an anode of the first diode is connected to the other end of the boost inductor;

[0034] a second diode, wherein the anode of the second diode is connected to the cathode of the first diode, and the cathode of the second diode serves as an output end of the boost circuit;

[0035] A second capacitor, one end of the second capacitor is connected to the anode of the second diode, and the other end of the second capacitor is grounded.

[0036] Optionally, the step-down circuit includes:

[0037] A step-down chip, wherein the input pin of the step-down chip is connected to the power input terminal;

[0038] Buck inductor, one end of which is connected to the output pin of the buck chip;

[0039] a third diode, wherein the anode of the third diode is connected to the other end of the step-down inductor, and the cathode of the third diode serves as the output end of the step-down circuit;

[0040] A third capacitor, one end of the third capacitor is connected to the anode of the third diode, and the other end of the third capacitor is grounded.

[0041] In the above embodiment, an input switching circuit is provided, which is applied to a wide range DC power supply device. The input switching circuit includes: a power input terminal, a power output terminal and a switching module. The switching module is configured to connect the power input terminal with the power output terminal when the power supply voltage of the DC power supply is less than the target voltage, so that the boost circuit performs a boost conversion on the DC power supply and outputs the target voltage; when the power supply voltage of the DC power supply is greater than the target voltage, the buck circuit performs a buck conversion on the DC power supply and outputs the target voltage, so that the power input terminal and the power output terminal are disconnected according to the target voltage. At this point, no external control signal is required, and automatic switching to a boost or buck working mode can be achieved based on input voltages in different ranges, so that the circuit can be applied to a power supply environment with a wide voltage range, increasing its applicability and flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 A schematic diagram of the circuit structure of an input switching circuit provided according to an embodiment of the present application;

[0044] Figure 2 A schematic diagram of the circuit structure of an input switching circuit provided according to another embodiment of the present application;

[0045] Figure 3 A circuit schematic diagram of an input switching circuit provided according to an embodiment of the present application;

[0046] Figure 4 A schematic diagram of the structure of a wide-range DC power supply device provided according to an embodiment of the present application;

[0047] Figure 5 A circuit schematic diagram of a boost circuit provided according to an embodiment of the present application;

[0048] Figure 6 The schematic diagram of a step-down circuit according to an embodiment of the present application is shown in FIG. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0050] In modern electronic systems, power management is a vital link. As the functions of electronic devices become increasingly diverse and complex, the requirements for power supply are also getting higher and higher. Different application scenarios may require different power supply voltages. For example, some portable devices may require lower voltage power supply, while some industrial equipment may require higher voltage. Therefore, wide-range DC voltage input has become an important design consideration. Among them, wide-range DC voltage input refers to the input voltage range that an electronic device or system can accept and work normally. The wider this range, the more different power supply environments the device can adapt to. In addition, the design of wide-range DC voltage input can also ensure that the device can operate stably in different power supply environments, thereby improving the reliability of the device and user experience.

[0051] In some related technologies, the need to achieve a wide range of DC voltage input is mainly achieved by using a DC-DC power module or selecting an appropriate DC-DC power chip. A DC-DC converter is an electronic device that can convert a DC power supply of one voltage level to another voltage level. It can be a boost converter, which increases the lower input voltage to the required output voltage; it can also be a buck converter, which reduces the higher input voltage to the required output voltage; or a buck-boost converter, which can increase or decrease the input voltage as needed. These converters are usually integrated in power modules or chips, providing an efficient, compact and reliable power solution. However, this solution still has some disadvantages:

[0052] 1. Wide-range DC-DC power supply chips are usually designed for a single function, that is, they can only perform step-up or step-down operations.

[0053] 2. DC-DC chips that meet dual functions usually have a narrow input voltage range and the output power is often not large, which cannot meet applications with high power requirements.

[0054] 3. To achieve a wide range of buck-boost functions, more complex circuit design and more components are usually required, including the use of multiple power chips, complex control logic, and additional protection and voltage stabilization circuits. This circuit design is more complex and its production cost will increase significantly.

[0055] Based on this, according to an embodiment of the present application, an input switching circuit is provided, such as Figure 1 As shown, the input switching circuit 100 includes a power input terminal 101 , a power output terminal 103 and a switching module 110 .

[0056] It should be noted that the input switching circuit 100 is applied to a wide-range DC power supply device. The wide-range DC power supply device includes a boost circuit 121 and a buck circuit 123 .

[0057] The power input terminal 101 may refer to a position in the circuit structure for receiving an external DC power supply, and is responsible for receiving the external power supply and transmitting the power supply to other parts of the circuit as needed.

[0058] Specifically, the power input terminal 101 is suitable for connecting the DC power supply 130 and the input terminal of the step-down circuit 123. The DC power supply 130 may be a power supply device for providing a stable DC voltage and current for use by an electronic device or circuit. The DC power supply 130 may provide a stable supply voltage for the input switching circuit 100 and a wide range DC power supply device. The step-down circuit 123 may be a circuit structure for reducing an input higher DC voltage to a lower DC voltage and outputting it. Specifically, the step-down circuit 123 may achieve voltage reduction by controlling the conduction time and duty cycle of the step-down chip and the switching element, and cooperating with the inductor and the capacitor to work.

[0059] The power output terminal 103 may refer to the position of the output voltage in the circuit structure, and is used to output the processed voltage to the next circuit structure. Specifically, the power output terminal 103 is suitable for connecting the input terminal of the boost circuit 121. Among them, the boost circuit 121 may be a circuit structure for boosting the input lower DC voltage to a higher DC voltage and outputting it. Similarly, the boost circuit can achieve voltage boosting through the conduction and shutdown of the boost chip and the switch element, as well as the energy storage and filtering of the inductor and the capacitor.

[0060] The switching module 110 may be a circuit structure that dynamically switches the connection mode of the circuit according to the relationship between the supply voltage and the target voltage. Exemplarily, the switching module 110 may include an electronic switch, such as a transistor or a MOSFET, and the switching module 110 may also be a group of logic circuits to achieve the purpose of switching the circuit connection mode.

[0061] Specifically, a first end of the switching module 110 is connected to the power input terminal 101 , a second end of the switching module 110 is suitable for connecting to the power output terminal 125 of the wide range DC power supply device, and a third end of the switching module 110 is connected to the power output terminal 103 .

[0062] It should be understood that the power supply output terminal 125 of the wide-range DC power supply device is different from the power supply output terminal 101. The power supply output terminal 101 is a circuit location where the switching module 110 outputs an intermediate voltage to the boost module after preliminary processing based on the power supply voltage of the DC power supply; and the power supply output terminal 125 of the wide-range DC power supply device is a circuit location where the buck circuit 123 outputs a target voltage after performing a step-down conversion based on the power supply voltage of the DC power supply, and inputs the target voltage as a control signal to the switching module 110, so that the switching module 110 disconnects the connection between the power input terminal 101 and the power output terminal 103.

[0063] Further, the switching module 110 is configured to connect the power input terminal 101 with the power output terminal 103 when the power supply voltage of the DC power supply 130 is less than the target voltage, so that the boost circuit 121 performs a boost conversion on the DC power supply 130 and outputs the target voltage; the switching module 110 is also configured to, when the power supply voltage of the DC power supply 130 is greater than the target voltage, the buck circuit 123 performs a buck conversion on the DC power supply 130 and outputs the target voltage, so that the power input terminal 101 and the power output terminal 103 are disconnected according to the target voltage.

[0064] The supply voltage of the DC power supply 130 may refer to the voltage level that the DC power supply 130 can provide. Exemplarily, the DC power supply 130 can provide a stable wide-range voltage input of 2.7V to 120V for the input switching circuit 110 and the wide-range DC power supply device, and its supply voltage may be any voltage value from 2.7V to 120V. The target voltage may refer to any pre-set voltage value that the wide-range DC power supply device needs to output and that can meet the voltage requirements of the connected external device. Exemplarily, the target voltage may be 12V, and the target voltage may also be 24V.

[0065] Further, the switching module 110 switches the working state of the circuit based on the power supply voltage received by the power input terminal 101 from the DC power supply 130 and the voltage value relationship between the power supply voltage and the target voltage. Exemplarily, if the power supply voltage is less than the target voltage, the switching module 110 connects the power input terminal 101 with the power output terminal 103 to put the boost circuit 121 in a working state. Further, the boost circuit 121 will increase the power supply voltage to the target voltage and finally provide it to the load. It can be understood that since the power input terminal 101 is also connected to the step-down circuit 123, that is, the step-down circuit 123 will also receive the power supply voltage of the DC power supply 130, then if the power supply voltage is greater than the target voltage, the step-down circuit 123 will directly step down the excessive power supply voltage, output the target voltage and provide it to the load. At the same time, the step-down circuit 123 will also use the target voltage as a voltage control signal, and input it into the switching module 110 through the power supply output terminal 125 of the wide-range DC power supply device, so as to control the switching module 110 to shut down the circuit connection state between the power input terminal 101 and the power output terminal 103, so as to prevent excessively high power supply voltage from directly supplying power to the boost circuit 121 and causing damage to the components of the boost circuit 121.

[0066] In the above embodiment, an input switching circuit is provided, which is applied to a wide range DC power supply device. The input switching circuit includes: a power input terminal, a power output terminal and a switching module. The switching module is configured to connect the power input terminal with the power output terminal when the power supply voltage of the DC power supply is less than the target voltage, so that the boost circuit performs a boost conversion on the DC power supply and outputs the target voltage; when the power supply voltage of the DC power supply is greater than the target voltage, the buck circuit performs a buck conversion on the DC power supply and outputs the target voltage, so that the power input terminal and the power output terminal are disconnected according to the target voltage. At this point, no external control signal is required, and automatic switching to a boost or buck working mode can be achieved based on input voltages in different ranges, so that the circuit can be applied to a power supply environment with a wide voltage range, increasing its applicability and flexibility.

[0067] In some embodiments, see Figure 2 The switching module 110 includes a first switch control unit 210 and a second switch control unit 220. The first end of the first switch control unit 210 is connected to the power input terminal 101, and the second end of the first switch control unit 210 is connected to the power output terminal 103; the first end of the second switch control unit 220 is connected to the power input terminal 101, and the second end of the second switch control unit 220 is suitable for connecting to the power output terminal 125 of the wide-range DC power supply device, and the output end of the second switch control unit 220 is connected to the control end of the first switch control unit 210.

[0068] Among them, the first switch control unit 210 and the second switch control unit 220 can both refer to different circuit parts in the switching module that work together based on different power supply conditions to achieve automatic switching of circuit working modes. However, it should be understood that the first switch control unit 210 can be the main switch unit in the switching module 110, which is responsible for directly controlling the connectivity between the power input terminal 101 and the power output terminal 103. Since the second end of the second switch control unit 220 is suitable for connecting the power supply output terminal 125 of the wide-range DC power supply device, the on and off of the second switch control unit 220 will be affected by whether the step-down circuit 123 outputs the target voltage, that is, the second switch control unit 220 can be an auxiliary switch in the switching module, and its output end is connected to the control end of the first switch control unit 210, which is used to control the on or off state of the first switch control unit 210 based on the voltage control signal output from the power supply output terminal 125.

[0069] Specifically, the second switch control unit 220 is turned off when the supply voltage of the DC power supply 130 is less than the target voltage, so that the first switch control unit 210 is turned on, and is turned on when the supply voltage of the DC power supply 130 is greater than the target voltage, so that the first switch control unit 210 is turned off.

[0070] For example, when the supply voltage of the DC power supply 130 is less than the target voltage, since the supply voltage needs to be boosted at this time, the step-down circuit 123 is not in the working state at this time, and the power supply output terminal 130 of the wide-range DC power supply device has no voltage control signal output, so that the second switch control unit 220 is in the off state, so that the first switch control unit 210 is turned on, thereby allowing the boost circuit 121 to intervene to provide the target voltage. On the contrary, when the supply voltage of the DC power supply 130 is greater than the target voltage, at this time, since the step-down circuit 123 will be in the working state and output the target voltage, that is, at this time, the power supply output terminal 125 of the wide-range DC power supply device has a voltage control signal output, so that the second switch control unit 220 is in the on state, which causes the first switch control unit 210 to be turned off, thereby preventing the excessively high supply voltage from being directly supplied to the boost circuit 121 and causing the components of the boost circuit 121 to be damaged.

[0071] In the above implementation, the first switch control unit and the second switch control unit work together to ensure that under different power supply conditions, the connection state between the power input terminal and the power output terminal can be automatically adjusted to maintain a stable output voltage and meet the target voltage requirements. The step-down circuit and the second switch unit can be regarded as forming a feedback control system, and based on the cooperation of the two switch control units, in conjunction with the feedback control system, the purpose of accurately controlling the output voltage based on input voltages in different ranges is achieved, ensuring the accuracy and stability of voltage conversion.

[0072] In some embodiments, see Figure 3 The first switch control unit 210 includes a first transistor Q1, a first resistor module 310, a second resistor R2 and a second transistor Q2.

[0073] The first transistor Q1 may be an NPN transistor as an electronic switch, which is only responsible for switching to an on or off working state based on different voltage input control. Specifically, the base of the first transistor Q1 serves as the control terminal of the first switch control unit 210, and the collector of the first transistor Q1 is connected to the power input terminal VCC through the first resistor module 310.

[0074] It can be understood that the first resistor module 310 connected between the collector of the first transistor Q1 and the power input terminal VCC constitutes a voltage divider, which can be used to provide an appropriate bias voltage for the base of the first transistor Q1 to ensure that the first transistor Q1 can correctly switch between the on and off states under the action of the control signal.

[0075] Furthermore, one end of the second resistor R2 is connected to the emitter of the first transistor Q1, the base of the second transistor Q2 is connected to the other end of the second resistor R2, the collector of the second transistor Q2 is connected to the power input terminal VCC, and the emitter of the second transistor Q2 is connected to the power output terminal VCC-L.

[0076] The second resistor R2 may be a resistor with a resistance of 0Ω, used as a backup resistor. In actual production and manufacturing, different resistance values ​​may be flexibly selected according to the specific models of the first transistor Q1 and the second transistor Q2, or different voltage output requirements.

[0077] It should be noted that the purpose of the second transistor Q2 is different from that of the first transistor Q1. The function of the second transistor Q2 is to reduce the voltage of the power input terminal VCC, generate a VCC-L voltage signal and input it to the boost module through the power output terminal. Therefore, based on this, when selecting the model of the second transistor Q2, a transistor that can withstand a certain current load and has sufficient voltage and current handling capabilities can be selected. For example, an NPN transistor of the FZT696BTA model can be used as the second transistor Q2.

[0078] In the above embodiment, the second transistor is used to first perform preliminary voltage processing on the power supply voltage at the power input end, and then input it to the boost module via the power output end. On the one hand, it can avoid that an excessively high power supply voltage is directly supplied to the boost circuit via the power input end, causing damage to components. On the other hand, a simple cascade switching circuit is formed in conjunction with the first transistor, so that the first switch control unit can be flexibly adjusted under different working conditions to meet the different voltage and current requirements of the circuit, thereby improving the adaptability and reliability of the circuit.

[0079] In some embodiments, the first resistor module includes a plurality of first resistors, and the plurality of first resistors are connected in parallel.

[0080] For example, taking two first resistors as an example, please continue to refer to Figure 3 The first resistor module 310 may include a plurality of first resistors R11 and R12. R11 and R12 may be resistors with the same resistance value, and R11 and R12 are connected in parallel between the first transistor Q1 and the power input terminal VCC, and are used to provide an appropriate bias voltage for the base of the first transistor Q1, ensuring that the first transistor Q1 can correctly switch between the on and off states under the action of the control signal.

[0081] In the above implementation, the first resistor module is formed by a plurality of first resistors connected in parallel, which can be used to reduce the total resistance value, thereby allowing more current to flow through and providing a stable base bias current for the first transistor. On the other hand, the parallel design is more flexible than the series and single resistors, and can better meet the bias current conditions required by different transistor models when performing specific circuit debugging.

[0082] In some embodiments, please continue to refer to Figure 3 The second switch control unit 220 includes a first voltage regulator tube D1, a third resistor R3, a third transistor Q3, a second resistor module 410 and a fourth resistor R4.

[0083] Among them, the first voltage regulator D1 can be a voltage regulator diode that acts as a switch, which can work when reverse biased, maintain cutoff when the input voltage does not reach the breakdown voltage, and turn on when the input voltage reaches its breakdown voltage. Exemplarily, the first voltage regulator D1 can be a transient suppression diode or a Zener diode. Specifically, the cathode of the first voltage regulator D1 is connected to the power supply output terminal of the wide-range DC power supply device. When the voltage output from the power supply output terminal is less than the breakdown voltage of the first voltage regulator D1, the first voltage regulator D1 maintains a shut-off working state; when the voltage output from the power supply output terminal is greater than or equal to the breakdown voltage of the first voltage regulator D1, the voltage can pass through the first voltage regulator D1 to turn it on.

[0084] Furthermore, one end of the third resistor R3 is connected to the anode of the first voltage regulator D1, and the other end of the third resistor R3 is connected to the base of the third triode Q3, the emitter of the third triode Q3 is grounded, the collector of the third triode Q3 is connected to the power input terminal VCC through the second resistor module 410, and the collector of the third triode Q3 serves as the output terminal of the second switch control unit 220.

[0085] Among them, the third resistor R3 can be used to limit the current flowing through the base of the first voltage regulator D1 and the third transistor Q3, protecting the first voltage regulator D1 and the third transistor Q3 from damage by excessive current. Similarly, the third transistor Q3 can be an NPN transistor as an electronic switch, which is only responsible for switching to an on or off working state based on different voltage input controls. The second resistor module 410 connected between the collector of the third transistor Q3 and the power input terminal VCC also constitutes a voltage divider, which can be used to provide an appropriate bias voltage for the base of the third transistor Q3 to ensure that the third transistor Q3 can work in coordination based on the state of whether the first voltage regulator D1 is on or not, so as to correctly switch the on and off states of the third transistor Q3.

[0086] Exemplarily, when the supply voltage of the DC power supply is less than the target voltage, the power supply output terminal of the wide-range DC power supply device has no voltage control signal output, and the first component of the second switch control unit 220, the first voltage regulator D1, is not broken down and maintains the off state. Further, since the base of the third transistor Q3 has no voltage output at this time (which can be regarded as a low voltage control state), the third transistor Q3 also maintains the off state, so the collector voltage of the third transistor Q3 remains unchanged, and does not affect the voltage state of the base of the first transistor Q1 in the first switch control unit 210, that is, the second switch control unit 220 is in the off state, so that the first switch control unit 210 is turned on, thereby allowing the boost circuit to intervene to provide the target voltage.

[0087] On the contrary, when the supply voltage of the DC power supply is greater than the target voltage, at this time, since the buck circuit will be in a corresponding working state and output the target voltage, that is, at this time, the power supply output end of the wide-range DC power supply device has a voltage control signal output, and the first component of the second switch control unit 220, the first voltage regulator D1, is reversely broken down, that is, the first voltage regulator D1 is turned on. Further, the base of the third transistor Q3 has a high voltage input, that is, the third transistor Q3 also becomes a conducting state. Since the emitter of the third transistor Q3 is grounded, when the third transistor Q3 is in a conducting state, the collector voltage of the third transistor Q3 is pulled down, and the base voltage of the first transistor Q1 in the first switch control unit 210 is further pulled down, causing the first transistor Q1 to be turned off, even if the second switch control unit is in a conducting state, the first switch control unit is correspondingly turned off, thereby preventing the excessively high supply voltage from being directly supplied to the boost circuit and causing the boost circuit components to be damaged.

[0088] Optionally, a fourth resistor R4 is connected between the base and emitter of the third triode Q3. Specifically, when there is a voltage input, the collector current of the third triode Q3 will increase, and at this time, more voltage will be across the fourth resistor R4, causing the base voltage of the third triode Q3 to drop, thereby reducing the base current of the third triode Q3 and limiting the excessive increase of the collector current of the third triode Q3. That is, the fourth resistor R4 can be used as a feedback resistor for providing negative feedback, which is used to stabilize the operating point of the third triode Q3, prevent the third triode Q3 from entering a saturation state, and ensure that the third triode Q3 operates in the amplification region.

[0089] In the above embodiment, multiple components are coordinated to form a multi-stage cascade control system. When the input voltage is lower than the target voltage, the first voltage regulator D1 is not turned on, and the third transistor Q3 is turned off, thereby allowing the first switch control unit to be turned on and the boost circuit to intervene in the work; when the input voltage is higher than the target voltage, the first voltage regulator D1 is turned on, and the third transistor Q3 is turned on, thereby causing the first switch control unit to be turned off, and finally the working state can be automatically switched according to the input voltage. At the same time, its circuit design only uses a simplified combination of voltage regulators and transistors, reducing the number of components required and realizing complex voltage control functions. Not only does it reduce costs, but it also improves the reliability and efficiency of the circuit.

[0090] In some embodiments, the second resistor module includes a plurality of fifth resistors, and the plurality of fifth resistors are connected in parallel.

[0091] For example, also taking two fifth resistors as an example, please continue to refer to Figure 3The second resistor module 410 may include a plurality of fifth resistors R51 and R52. R51 and R52 may be resistors with the same resistance value, and R51 and R52 are connected in parallel between the third transistor Q3 and the power input terminal VCC, and are used to provide an appropriate bias voltage for the base of the third transistor Q3, ensuring that the third transistor Q3 can correctly switch between the on and off states under the action of the control signal.

[0092] In the above embodiment, the second resistor module is also formed by multiple fifth resistors connected in parallel, which can be used to reduce the total resistance value, thereby allowing more current to flow through and providing a stable base bias current for the third transistor. On the other hand, the parallel design is more flexible than the series and single resistor design, and can better meet the bias current conditions required by different transistor models.

[0093] In some embodiments, please continue to refer to Figure 3 The switching module also includes a second voltage regulator tube D2 and a first capacitor C1.

[0094] Among them, the second voltage regulator D2 can also be a voltage regulator diode to prevent excessive voltage from causing damage to the circuit. When the input voltage exceeds the stable voltage of the second voltage regulator D2, the second voltage regulator D2 is reversely conducted to consume the excess voltage, thereby protecting the circuit. Specifically, the anode of the second voltage regulator D2 is grounded, and the cathode of the second voltage regulator D2 is connected to the output end of the second switch control unit 220 and the control end of the first switch control unit 210, respectively. That is, when the output voltage of the second switch control unit 220 exceeds the breakdown voltage of the second voltage regulator D2, the second voltage regulator D2 is turned on to release the excess voltage to the ground, thereby protecting the first switch control unit 210 from being affected by excessive voltage.

[0095] Furthermore, the first capacitor C1 is connected in parallel with the second voltage regulator D2 to smooth voltage fluctuations. The first capacitor C1 can absorb voltage spikes and transients, reduce the impact of voltage fluctuations on the circuit, and provide a stable voltage to the control end of the first switch control unit 210.

[0096] In the above embodiment, by connecting the second voltage regulator tube and the first capacitor in parallel between the output end of the second switch control unit 220 and the control end of the first switch control unit 210, the circuit can maintain a stable voltage output when facing voltage fluctuations. At the same time, the circuit can be protected from transient voltages, thereby improving the reliability and stability of the circuit.

[0097] The present application also provides a wide range DC power supply device 600, please refer to Figure 4 The device includes: a boost circuit 610 and a buck circuit 620.

[0098] According to the input switching circuit mentioned in the above embodiment, the boost circuit 610 and the buck circuit 620 are switched to work respectively based on the input DC power supply voltage.

[0099] The specific configuration and further functional description of the above-mentioned input switching circuit are the same as those of the above-mentioned corresponding embodiments and will not be repeated here.

[0100] In some embodiments, see Figure 5 The boost circuit 610 includes a boost inductor L1, a boost chip U1, a first diode D1, a second diode D2 and a second capacitor C2.

[0101] The boost chip U1 may be a boost converter for boosting a lower input voltage to a higher output voltage. For example, the boost chip U1 may be a DC-DC power supply chip of model LM2733YMF.

[0102] Further, one end of the boost inductor L1 is connected to the power supply output terminal VCC-L. The input pin of the boost chip U1 is connected to one end of the boost inductor L1, and the output pin of the boost chip U1 is connected to the other end of the boost inductor L1. The anode of the first diode D1 is connected to the other end of the boost inductor L1, the anode of the second diode D2 is connected to the cathode of the first diode D1, and the cathode of the second diode D2 serves as the output end of the boost circuit. One end of the second capacitor C2 is connected to the anode of the second diode D1, and the other end of the second capacitor C2 is grounded.

[0103] Among them, the first diode D1 can be a boost diode or a freewheeling diode, which is used to provide a release path for the energy in the boost inductor L1 when the switch tube of the boost chip U1 is turned off, to prevent the current of the boost inductor L1 from being suddenly interrupted, so as to maintain the continuity of the current. At the same time, the energy in the boost inductor L1 can also flow to the output end through the first diode D1, and the output voltage is rectified at the same time to ensure the correct polarity of the output voltage. The second diode D2 can be a Schottky diode to prevent reverse current, which is used to reduce the impact of surge voltage on the circuit and protect other components in the boost circuit. Specifically, during the operation of the boost circuit, the boost chip U1 will use the energy storage and release characteristics of the inductor and capacitor to achieve the boost operation of the input voltage. When the built-in switch tube in the boost chip U1 is turned on, the boost inductor L1 stores energy; when its switch tube is turned off, the stored energy in the boost inductor L1 is released to the output end through the first diode D1 and the second diode D2, and the size and stability of the output voltage are adjusted in combination with the peripheral resistor. Optionally, two feedback voltage-dividing resistors are connected to the FB pin of the boost chip U1. The voltage fed back to the FB pin can be determined by designing the ratio of the two resistors, thereby setting the specific voltage value of the final output voltage. At the same time, the second capacitor C2 serves as a filter capacitor at the output end to help smooth the output voltage and reduce voltage fluctuations.

[0104] In the above embodiment, the lower input voltage can be increased to a higher output voltage through the coordinated operation of the boost inductor, the boost chip, the first diode, the second diode, the second capacitor and the feedback voltage divider resistor, thereby achieving effective conversion of the input voltage to the output voltage while ensuring the stability, efficiency and protection of the circuit.

[0105] In some embodiments, see Figure 6 The buck circuit 620 includes a buck chip U2, a buck inductor L2, a third diode D3 and a third capacitor C3.

[0106] Among them, the input pin of the buck chip U2 is connected to the power input terminal VCC. One end of the buck inductor L2 is connected to the output pin of the buck chip U2, the anode of the third diode D3 is connected to the other end of the buck inductor L2, and the cathode of the third diode D3 serves as the output end of the buck circuit. One end of the third capacitor C3 is connected to the anode of the third diode, and the other end of the third capacitor is grounded.

[0107] Similarly, the buck chip U2 can be a buck converter for reducing a higher input voltage to a lower output voltage. Exemplarily, the buck chip U2 can use a DC-DC power supply chip of model LM5168PQDDARQ1, which has a built-in freewheeling diode. The third diode D3 can be a Schottky diode to prevent reverse current, which is used to reduce the impact of surge voltage on the circuit and protect other components in the buck circuit. Furthermore, the buck circuit controls the charging and discharging process of the buck inductor L2 through the buck chip U2, cooperates with its peripheral feedback capacitor and resistor, and adjusts the size and stability of the output voltage through the switching circuit and the control circuit, and finally reduces the higher input voltage to a lower output voltage. And the third capacitor C3 is used to smooth the output voltage, reduce voltage fluctuations, and provide a stable output.

[0108] In the above implementation, the high input voltage can be reduced to a low output voltage through the coordinated work of the step-down inductor, the step-down chip, the third diode, the third capacitor and the feedback voltage-dividing resistor, thereby achieving effective conversion from input voltage to output voltage, while also ensuring the stability, efficiency and protection of the circuit. On the other hand, by using different types of DC-DC power supply chips, the circuit structure can be more reasonably designed and components can be selected, thereby improving the efficiency of power conversion and reducing energy loss.

[0109] It should be understood that an input switching circuit and a wide-range DC power supply device in the present embodiment are presented in the form of functional units, where the units refer to ASIC (Application Specific Integrated Circuit) circuits, processors and memories that execute one or more software or fixed programs, and / or other devices that can provide the above functions. Each module in the above-mentioned input switching circuit and wide-range DC power supply device can be implemented in whole or in part through software, hardware, and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above-mentioned modules.

[0110] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0111] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0112] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0113] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0114] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0115] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

[0116] Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An input switching circuit, characterized in that: Applicable to a wide-range DC power supply device, the wide-range DC power supply device comprises a boost circuit and a buck circuit, the boost circuit has an input end and an output end, the buck circuit has an input end and an output end; The input switching circuit comprises: A power input terminal connected to a DC power supply and an input terminal of the step-down circuit, and an output terminal of the step-down circuit connected to a power supply output terminal of the wide-range DC power supply device; A power supply output end, connected to the input end of the boost circuit, and the output end of the boost circuit is connected to the power supply output end of the wide-range DC power supply device; a switching module, wherein a first end of the switching module is connected to the power input end, a second end of the switching module is connected to the power output end of the wide-range DC power supply device, and a third end of the switching module is connected to the power output end, and the switching module is configured as follows: When the supply voltage of the DC power supply is lower than the target voltage, the power supply input terminal is connected to the power supply output terminal so that the boost circuit performs a boost conversion on the DC power supply to output the target voltage; When the supply voltage of the DC power supply is greater than the target voltage, the step-down circuit steps down the DC power supply, outputs the target voltage, and inputs the target voltage as a voltage control signal to the switching module through the power supply output terminal, so that the switching module disconnects the power supply input terminal and the power supply output terminal according to the target voltage.

2. The input switching circuit according to claim 1, characterized in that: The switching module comprises: a first switch control unit, wherein a first end of the first switch control unit is connected to the power input end, and a second end of the first switch control unit is connected to the power output end; a second switch control unit, wherein a first end of the second switch control unit is connected to the power input end, a second end of the second switch control unit is connected to the power supply output end of the wide-range DC power supply device, an output end of the second switch control unit is connected to a control end of the first switch control unit, and the second switch control unit is configured as: When the supply voltage of the DC power supply is less than the target voltage, the power supply output terminal of the wide-range DC power supply device has no voltage control signal output, and the second switch control unit is turned off so that the first switch control unit is turned on; When the supply voltage of the DC power supply is greater than the target voltage, a voltage control signal is output at the power supply output end of the wide-range DC power supply device, thereby turning on the second switch control unit so that the first switch control unit is turned off.

3. The input switching circuit according to claim 2, characterized in that: The first switch control unit comprises: A first transistor, wherein the base of the first transistor serves as a control terminal of the first switch control unit, and the collector of the first transistor is connected to the power input terminal through a first resistor module; a second resistor, one end of which is connected to the emitter of the first transistor; A second triode, wherein the base of the second triode is connected to the other end of the second resistor, the collector of the second triode is connected to the power input end, and the emitter of the second triode is connected to the power output end.

4. The input switching circuit according to claim 3, characterized in that: The first resistor module includes a plurality of first resistors, and the plurality of first resistors are connected in parallel.

5. The input switching circuit according to claim 2, characterized in that: The second switch control unit comprises: A first voltage regulator tube, wherein the cathode of the first voltage regulator tube is connected to the power supply output end of the wide-range DC power supply device; a third resistor, one end of which is connected to the anode of the first voltage regulator tube; a third triode, wherein the base of the third triode is connected to the other end of the third resistor, the emitter of the third triode is grounded, the collector of the third triode is connected to the power input end through the second resistor module, and the collector of the third triode serves as the output end of the second switch control unit; A fourth resistor is connected between the base and the emitter of the third transistor.

6. The input switching circuit according to claim 5, characterized in that: The second resistor module includes a plurality of fifth resistors, and the plurality of fifth resistors are connected in parallel.

7. The input switching circuit according to any one of claims 2 to 6, characterized in that: The switching module also includes: a second voltage regulator tube, wherein an anode of the second voltage regulator tube is grounded, and a cathode of the second voltage regulator tube is respectively connected to an output end of the second switch control unit and a control end of the first switch control unit; A first capacitor is connected in parallel with the second voltage regulator tube.

8. A wide range DC power supply device, characterized in that: include: Boost circuit and buck circuit; According to the input switching circuit described in any one of claims 1 to 7, the input switching circuit switches the boost circuit and the buck circuit to work separately based on the input DC power supply voltage.

9. The wide range DC power supply device according to claim 8, characterized in that: The boost circuit comprises: A boost inductor, one end of which is connected to the power output end; A boost chip, wherein an input pin of the boost chip is connected to one end of the boost inductor, and an output pin of the boost chip is connected to the other end of the boost inductor; a first diode, wherein an anode of the first diode is connected to the other end of the boost inductor; a second diode, wherein an anode of the second diode is connected to a cathode of the first diode, and the cathode of the second diode serves as an output end of the boost circuit; A second capacitor, one end of the second capacitor is connected to the anode of the second diode, and the other end of the second capacitor is grounded.

10. The wide range DC power supply device according to claim 8, characterized in that: The step-down circuit comprises: A step-down chip, wherein an input pin of the step-down chip is connected to the power input terminal; A buck inductor, one end of which is connected to an output pin of the buck chip; a third diode, wherein an anode of the third diode is connected to the other end of the step-down inductor, and a cathode of the third diode serves as an output end of the step-down circuit; A third capacitor, one end of the third capacitor is connected to the anode of the third diode, and the other end of the third capacitor is grounded.

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