Voltage conversion circuit and voltage conversion device

Abstract

The embodiment of the utility model discloses a voltage conversion circuit and a voltage conversion device. The voltage conversion circuit comprises an input end used for inputting a first voltage; the output end is used for outputting a second voltage; a first voltage transformation module and a second voltage transformation module, the first voltage transformation module is connected between the input end and the output end, the second voltage transformation module is connected between the first voltage transformation module and the grounding end, and the first voltage transformation module and the second voltage transformation module are used for reducing the first voltage and outputting a second voltage; the filtering module is connected between the first voltage transformation module and / or the second voltage transformation module and the output end, and the filtering module is used for stabilizing the second voltage; the first voltage transformation module is used for reverse blocking when the second voltage is greater than or equal to the first voltage. According to the technical scheme provided by the embodiment, the problem that devices of the voltage conversion circuit are damaged due to the fact that current flows back to the input end in the voltage conversion circuit is solved.

Description

Technical Field

[0001] The embodiments of the utility model relate to the technical field of voltage reduction, and in particular to a voltage conversion circuit and a voltage conversion device. Background Art

[0002] Existing voltage conversion circuits generally step down the input voltage to output a voltage. When the output voltage of the existing step-down circuit is greater than the input voltage, the current will flow back to the input terminal through the inductor, which may easily damage the components of the voltage conversion circuit.

[0003] The existing voltage conversion circuit has the problem of current backflow to the input terminal causing damage to the components of the voltage conversion circuit, which has become a technical problem that needs to be solved urgently in the industry. Utility Model Content

[0004] The embodiments of the utility model provide a voltage conversion circuit and a voltage conversion device to solve the problem that the voltage conversion circuit has a current backflow to the input end, which causes the components of the voltage conversion circuit to be damaged.

[0005] In order to achieve the above technical problems, the utility model adopts the following technical solutions:

[0006] The present invention provides a voltage conversion circuit, comprising:

[0007] An input terminal, used for inputting a first voltage;

[0008] An output terminal, used for outputting a second voltage;

[0009] A first transformer module and a second transformer module, wherein the first transformer module is connected between the input terminal and the output terminal, and the second transformer module is connected between the first transformer module and a ground terminal, and the first transformer module and the second transformer module are used to step down the first voltage and output the second voltage; a filter module is connected between the first transformer module and the second transformer module and the output terminal, and the filter module is used to stabilize the second voltage;

[0010] The first voltage transformation module is used for reverse blocking when the second voltage is greater than or equal to the first voltage.

[0011] Optionally, the first voltage transformation module includes:

[0012] A gallium nitride switch tube, wherein the gallium nitride switch tube and the second voltage transformation module are connected to a first node;

[0013] The output end is connected to the first node, and the output end is used to output the second voltage when the gallium nitride switch tube is turned on;

[0014] The gallium nitride switch tube is used to be turned off and reverse blocked when the second voltage is greater than or equal to the first voltage.

[0015] Optionally, the voltage conversion circuit further includes:

[0016] A control module, wherein the control module is connected to the control end of the first transformer module, and the control module is used to control the first transformer module to be turned on when the second voltage is lower than the second voltage; and to control the first transformer module to be turned off and reverse blocked when the second voltage is greater than or equal to the first voltage.

[0017] Optionally, the control module includes:

[0018] A forward conducting unit, wherein the first end of the forward conducting unit is connected to the first power supply end, the second end of the forward conducting unit is connected to the control end of the first transformer module, the third end of the forward conducting unit is connected to the first pole of the first transformer module, and the second pole of the first transformer module is connected to the input end; the forward conducting unit is used to output a conduction control signal when the second voltage is less than the first voltage; the conduction control signal is used to control the first transformer module to step down the first voltage and output a second voltage.

[0019] Optionally, the forward conducting unit includes:

[0020] A first switch tube and a buck circuit driver;

[0021] The first end of the first switch tube is connected to the first power supply end, and the second end of the first switch tube is connected to the control end of the first transformer module;

[0022] The first control end of the step-down circuit driver is connected to the control end of the first switch tube, and the first control end is used to control the first switch tube to conduct when the second voltage is less than the first voltage, so as to output a conduction control signal to the control end of the first transformer module.

[0023] Optionally, the forward conducting unit further includes:

[0024] a second switch tube, wherein a first end of the second switch tube is connected to a second end of the first switch tube and a control end of the first transformer module, a second end of the second switch tube is connected to a first electrode of the first transformer module, and a control end of the second switch tube is connected to a second control end of the step-down circuit driver;

[0025] The second control end is used to control the second switch tube to be turned off when the second voltage is lower than the first voltage, so as to output a conduction control signal to the control end of the first transformer module.

[0026] Optionally, the control module further includes:

[0027] A reverse blocking unit, wherein the first end of the reverse blocking unit is connected to the control end of the first transformer module, the second end of the reverse blocking unit is connected to the second power supply end, and the reverse blocking unit is used to generate a blocking control signal when the first voltage is less than or equal to the second voltage; the blocking control signal is used to control the reverse blocking of the first transformer module.

[0028] Optionally, the reverse blocking unit comprises:

[0029] a third switch tube, wherein a first end of the third switch tube is connected to the control end of the first transformer module, and a second end of the third switch tube is connected to the second power supply end;

[0030] A reverse blocking controller, wherein the third control end of the reverse blocking controller is connected to the control end of the switch tube, and the reverse blocking controller is used to control the third switch tube to be turned on when the first voltage is less than or equal to the second voltage, so as to control the first transformer module to be turned off.

[0031] Optionally, the second voltage transformation module includes at least one switching transistor; the switching transistor includes a body diode;

[0032] The filtering module comprises: a capacitor connected between the output end of the first transformer module and / or the output end of the second transformer module and the output end of the voltage conversion circuit;

[0033] Alternatively, the filtering module includes: an inductor and a capacitor, the first end of the inductor is connected to the output end of the first transformer module and / or the output end of the second transformer module, the second end of the inductor is connected to the first end of the capacitor and the output end of the voltage conversion circuit, and the second end of the capacitor is connected to the ground end.

[0034] According to another aspect of the utility model, this embodiment provides a voltage conversion device, including: the voltage conversion circuit proposed in any one of the first aspects.

[0035] The voltage conversion circuit provided by the embodiment of the utility model can realize forward voltage reduction and reverse blocking by setting the first voltage conversion module. This arrangement can better avoid the current at the output end of the voltage conversion circuit from flowing back to the input end, thereby better avoiding damage to the components of the voltage conversion circuit and increasing the life of the voltage conversion circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0037] Figure 1 It is a structural schematic diagram of a voltage conversion circuit provided by an embodiment of the utility model;

[0038] Figure 2 It is a structural schematic diagram of another voltage conversion circuit provided by an embodiment of the utility model;

[0039] Figure 3 This is a structural schematic diagram of another voltage conversion circuit provided by an embodiment of the utility model;

[0040] Figure 4 This is a structural schematic diagram of another voltage conversion circuit provided by an embodiment of the utility model;

[0041] Figure 5 This is a structural schematic diagram of another voltage conversion circuit provided by an embodiment of the utility model;

[0042] Figure 6 This is a structural schematic diagram of another voltage conversion circuit provided by an embodiment of the utility model;

[0043] Figure 7 It is a schematic diagram of the structure of a voltage conversion circuit including a switched capacitor voltage converter provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0045] Based on the above technical problems, this embodiment proposes the following solutions:

[0046] Figure 1 Schematic diagram of a voltage conversion circuit provided by an embodiment of the utility model. Figure 1The voltage conversion circuit provided by the embodiment of the utility model includes: an input terminal VIN, used to input a first voltage; an output terminal VOUT, used to output a second voltage; a first transformer module 1 and a second transformer module 2, the first transformer module 1 is connected between the input terminal VIN and the output terminal VOUT, the second transformer module 2 is connected between the first transformer module 1 and the ground terminal, the first transformer module 1 and the second transformer module 2 are used to step down the first voltage and output the second voltage; a filter module 4 is connected between the first transformer module 1 and / or the second transformer module 2 and the output terminal VOUT, the filter module 4 is used to stabilize the second voltage; the first transformer module 1 is used to reverse block when the second voltage is greater than or equal to the first voltage.

[0047] Specifically, the input terminal VIN is used to input a first voltage. After being transformed by the first transformer module 1 and the second transformer module 2, the output terminal VOUT outputs a stepped-down second voltage. The stepped-down second voltage is filtered and stabilized by the filter module 4, so that the second voltage output by the filter module 4 is a stable DC voltage. The stable second voltage after filtering by the filter module 4 is output through the output terminal VOUT. The first transformer module 1 and the second transformer module 2 are both turned on, and the first transformer module 1 and the second transformer module 2 realize the step-down of the second voltage output by the output terminal VOUT through voltage division transformation, and the first transformer module 1 can realize the step-down effect.

[0048] When the second voltage of the output terminal VOUT is higher, so that the first voltage of the input terminal VIN is lower than the second voltage of the output terminal VOUT, the first transformer module 1 is reliably shut down, and the first transformer module 1 plays a reverse blocking role. The first transformer module 1 can better prevent the large current of the output terminal VOUT from flowing back to the input terminal VIN.

[0049] The voltage conversion circuit provided in this embodiment can only realize forward voltage reduction and reverse blocking by setting the first voltage conversion module 1. This arrangement can better avoid the current of the output terminal VOUT of the voltage conversion circuit from flowing back to the input terminal VIN, thereby better avoiding the damage of the components of the voltage conversion circuit and improving the life of the voltage conversion circuit.

[0050] Optional, Figure 2 FIG. 1 is a schematic diagram of another voltage conversion circuit provided by an embodiment of the utility model. Figure 2 , the first transformer module 1, including: a gallium nitride switch tube M H , GaN switch tube M H The second voltage transformation module 2 is connected to the first node N1; the output terminal VOUT is connected to the first node N1, and the output terminal VOUT is used to switch the GaN switch tube M H When turned on, the second voltage is output; the gallium nitride switch tube MH Used to shut down when the second voltage is greater than or equal to the first voltage, and to reverse block.

[0051] Specifically, due to the gallium nitride switch tube M H There is no body diode. H The control end control can realize the control of the GaN switch tube M H When the GaN switch tube M is forward-conducted, the first voltage inputted to the input terminal VIN is stepped down. H The control end control can realize the control of the GaN switch tube M H The reverse blocking can better improve the two functions of forward voltage reduction and reverse blocking of the voltage conversion circuit, thereby avoiding the backflow of the voltage conversion circuit and reducing the cost of the voltage conversion circuit.

[0052] Optional, Figure 3 This is a schematic diagram of the structure of another voltage conversion circuit provided by the embodiment of the utility model. Figure 3 The voltage conversion circuit also includes a control module 3, which is connected to the control end of the first transformer module 1. The control module 3 is used to control the first transformer module 1 to be turned on when the second voltage is lower than the first voltage; and to control the first transformer module 1 to be turned off and reversely blocked when the second voltage is greater than or equal to the first voltage.

[0053] Specifically, the control module 3 can generate a conduction control signal and a blocking control signal. The control module 3 is also connected to the control end of the second transformer module 2. When the voltage conversion circuit needs to step down, the control module 3 controls the first transformer module 1 and the second transformer module 2 to be turned on, so as to step down the first voltage input to the input terminal VIN and output the second voltage.

[0054] An inductor module may be provided between the output terminal VOUT and the first node N1. When there is a reverse current under the action of the inductor connected to the output terminal VOUT, since the control module 3 controls the first transformer module 1 to be turned off, the first transformer module 1 has no body diode, so that the first transformer module 1 can be reliably turned off, thereby better avoiding the problem of current backflow when the second voltage of the output terminal VOUT is higher than the first voltage of the input terminal VIN, thereby improving the safety of the voltage conversion circuit.

[0055] Optional, Figure 4 This is a schematic diagram of the structure of another voltage conversion circuit provided by the embodiment of the utility model. Figure 4The control module 3 includes: a forward conducting unit 31, a first end of the forward conducting unit 31 is connected to the first power supply end VH, a second end of the forward conducting unit 31 is connected to the control end of the first transformer module 1, a third end of the forward conducting unit 31 is connected to the first pole of the first transformer module 1, and the second pole of the first transformer module 1 is connected to the input end VIN; the forward conducting unit 31 is used to output a conduction control signal when the second voltage is less than the first voltage; the conduction control signal is used to control the first transformer module 1 to step down the first voltage and output the second voltage.

[0056] Specifically, when the voltage conversion circuit needs to step down the output, the forward conduction unit 31 outputs a conduction control signal. The conduction control signal can be, for example, a first power supply signal output by the first power supply terminal VH, such as a high level signal. The control end of the first transformer module 1 is turned on after receiving the conduction control signal, so that the first voltage inputted from the input terminal VIN is stepped down through the turned-on first transformer module 1, and a second voltage with a lower output voltage is outputted.

[0057] Optional, Figure 5 This is a schematic diagram of the structure of another voltage conversion circuit provided by the embodiment of the utility model. Figure 5 The forward conduction unit 31 includes: a first switch tube S1 and a buck circuit driver 311; the first end of the first switch tube S1 is connected to the first power supply end VH, and the second end of the first switch tube S1 is connected to the control end of the first transformer module 1; the first control end of the buck circuit driver 311 is connected to the control end of the first switch tube S1, and the first control end is used to control the first switch tube S1 to conduct when the second voltage is less than the first voltage, so as to output a conduction control signal to the control end of the first transformer module 1.

[0058] Specifically, when the second voltage is lower than the first voltage, the first control terminal of the buck circuit driver 311 outputs a driving signal, and the driving signal is used to control the first switch tube S1 to be turned on.

[0059] Optionally, based on the above embodiment, continue to refer to Figure 5 The forward conduction unit 31 also includes: a second switch tube S2, a first end of the second switch tube S2 is connected to the second end of the first switch tube S1 and the control end of the first transformer module 1, a second end of the second switch tube S2 is connected to the first pole of the first transformer module 1, and the control end of the second switch tube S2 is connected to the second control end of the step-down circuit driver 311; the second control end is used to control the second switch tube S2 to turn off when the second voltage is less than the first voltage, so as to output a conduction control signal to the control end of the first transformer module 1.

[0060] Specifically, when the second voltage is less than the first voltage, the second control terminal controls the second switch tube S2 to turn off. The first control terminal controls the first switch tube S1 to turn on, so as to output a conduction control signal, such as a high level signal, to the control terminal of the first transformer module 1 .

[0061] When the second voltage is greater than or equal to the first voltage, the control signal output by the second control terminal controls the second switch tube S2 to be turned off, and the second switch tube S2 is not provided with a body diode.

[0062] Optionally, based on the above embodiment, continue to refer to Figure 4 The control module 3 also includes: a reverse blocking unit 32, a first end of the reverse blocking unit 32 is connected to the control end of the first transformer module 1, a second end of the reverse blocking unit 32 is connected to the second power supply end VL, and the reverse blocking unit 32 is used to generate a blocking control signal when the first voltage is less than or equal to the second voltage; the blocking control signal is used to control the reverse blocking of the first transformer module 1.

[0063] Specifically, when the voltage conversion circuit needs to step down the output, the reverse blocking unit 32 does not output the blocking control signal. When the first voltage is less than or equal to the second voltage, the voltage conversion circuit needs to be reverse blocked, and the reverse blocking unit 32 outputs the blocking control signal. The blocking control signal can be, for example, a second power supply signal output by the second power supply terminal VL, such as a low-level signal. After receiving the blocking control signal, the control end of the first transformer module 1 is reversely blocked so that the second voltage of the output terminal VOUT is blocked from the reverse current through the turned-off first transformer module 1.

[0064] Optionally, based on the above embodiment, continue to refer to Figure 5 The reverse blocking unit 32 includes: a third switch tube S3, a first end of the third switch tube is connected to the control end of the first transformer module 1, and a second end of the third switch tube is connected to the second power supply end VL; a reverse blocking controller 321, a third control end of the reverse blocking controller 321 is connected to the control end of the switch tube, and the reverse blocking controller 321 is used to control the third switch tube to be turned on when the first voltage is less than or equal to the second voltage, so as to control the first transformer module 1 to be turned off.

[0065] Specifically, when the third switch tube is turned on, the second power supply terminal VL inputs a second power supply signal, such as a low-level signal, to the control terminal of the first transformer module 1, so that the first transformer module 1 is reliably shut down and reverse blocking can be achieved. Optionally, the voltage input to the second power supply terminal VL can be set to 0V, so that the reverse voltage of the input terminal VIN is zero.

[0066] Optional, Figure 6 This is a schematic diagram of the structure of another voltage conversion circuit provided by the embodiment of the utility model. Figure 6 The second transformer module 2 includes at least one switching transistor M L ; Switching transistor M L Including the body diode.

[0067] Specifically, Figure 6 The second transformer module 2 is shown as an example including a switch transistor M L No limitation is made here.

[0068] Optionally, based on the above embodiment, continue to refer to Figure 6 The filtering module 4 may include: an inductor L and a capacitor C, a first end of the inductor L is connected to the output end of the first transformer module 1 and / or the output end of the second transformer module 2, a second end of the inductor L is connected to the first end of the capacitor C and the output end VOUT, and a second end of the capacitor C is connected to the ground end.

[0069] Specifically, by setting the inductor L and the capacitor C, the stepped-down second voltage is filtered by the inductor L and the capacitor C to be a stable DC voltage, so that the second voltage outputted by the output terminal VOUT meets the requirement.

[0070] It should be noted that Figure 6 The example shows a situation where the first end of the inductor L is connected to both the output end of the first transformation module 1 and the output end of the second transformation module 2 .

[0071] In another optional implementation, the filtering module includes: a capacitor connected between the output end of the first transformer module and / or the output end of the second transformer module and the output end of the voltage conversion circuit.

[0072] This embodiment provides a voltage conversion device. The voltage conversion device provided by this embodiment includes the voltage conversion circuit proposed in any of the above embodiments, and has the beneficial effects of the voltage conversion circuit proposed in any of the above embodiments, which will not be described in detail here.

[0073] Exemplarily, the voltage conversion device may include a switched capacitor voltage converter. Figure 7 FIG. 1 is a schematic diagram of a voltage conversion circuit including a switched capacitor voltage converter provided by an embodiment of the utility model. Figure 7 The first transistor of the switched capacitor voltage converter is a gallium nitride switch tube M of the first voltage conversion module 1. H The second transistor Q2, the third transistor Q3 and the fourth transistor Q4 of the switched capacitor voltage converter can be used together as the switching transistor M of the second voltage conversion module 2. L ( Figure 7This arrangement enables the switched capacitor voltage converter to achieve both forward voltage reduction and reverse blocking, thereby effectively preventing the current at the output end of the switched capacitor voltage converter from flowing back to the input end, thereby effectively preventing the switched capacitor voltage converter from being damaged and increasing the service life of the switched capacitor voltage converter.

[0074] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A voltage conversion circuit, characterized in that: include: An input terminal, used for inputting a first voltage; An output terminal, used for outputting a second voltage; A first transformer module and a second transformer module, wherein the first transformer module is connected between the input end and the output end, and the second transformer module is connected between the first transformer module and a ground end, and the first transformer module and the second transformer module are used to step down the first voltage and output the second voltage; a filter module, connected between the first transformer module and / or the second transformer module and the output end, the filter module being used to stabilize the second voltage; The first voltage transformation module is used for reverse blocking when the second voltage is greater than or equal to the first voltage.

2. The voltage conversion circuit according to claim 1, characterized in that: The first transformer module comprises: A gallium nitride switch tube, wherein the gallium nitride switch tube and the second voltage transformation module are connected to a first node; The output end is connected to the first node, and the output end is used to output the second voltage when the gallium nitride switch tube is turned on; The gallium nitride switch tube is used to be turned off and reverse blocked when the second voltage is greater than or equal to the first voltage.

3. The voltage conversion circuit according to claim 1, characterized in that: The voltage conversion circuit further includes: A control module, wherein the control module is connected to the control end of the first transformer module, and the control module is used to control the first transformer module to be turned on when the second voltage is lower than the second voltage; and to control the first transformer module to be turned off and reverse blocked when the second voltage is greater than or equal to the first voltage.

4. The voltage conversion circuit according to claim 3, characterized in that: The control module comprises: A forward conducting unit, wherein the first end of the forward conducting unit is connected to the first power supply end, the second end of the forward conducting unit is connected to the control end of the first transformer module, the third end of the forward conducting unit is connected to the first pole of the first transformer module, and the second pole of the first transformer module is connected to the input end; the forward conducting unit is used to output a conduction control signal when the second voltage is less than the first voltage; the conduction control signal is used to control the first transformer module to step down the first voltage and output a second voltage.

5. The voltage conversion circuit according to claim 4, characterized in that: The forward conducting unit comprises: A first switch tube and a buck circuit driver; The first end of the first switch tube is connected to the first power supply end, and the second end of the first switch tube is connected to the control end of the first transformer module; The first control end of the step-down circuit driver is connected to the control end of the first switch tube, and the first control end is used to control the first switch tube to conduct when the second voltage is less than the first voltage, so as to output a conduction control signal to the control end of the first transformer module.

6. The voltage conversion circuit according to claim 5, characterized in that: The forward conducting unit further includes: a second switch tube, wherein a first end of the second switch tube is connected to a second end of the first switch tube and a control end of the first transformer module, a second end of the second switch tube is connected to a first electrode of the first transformer module, and a control end of the second switch tube is connected to a second control end of the step-down circuit driver; The second control end is used to control the second switch tube to be turned off when the second voltage is lower than the first voltage, so as to output a conduction control signal to the control end of the first transformer module.

7. The voltage conversion circuit according to claim 4, characterized in that: The control module further includes: A reverse blocking unit, wherein the first end of the reverse blocking unit is connected to the control end of the first transformer module, the second end of the reverse blocking unit is connected to the second power supply end, and the reverse blocking unit is used to generate a blocking control signal when the first voltage is less than or equal to the second voltage; the blocking control signal is used to control the reverse blocking of the first transformer module.

8. The voltage conversion circuit according to claim 7, characterized in that: The reverse blocking unit comprises: a third switch tube, wherein a first end of the third switch tube is connected to the control end of the first transformer module, and a second end of the third switch tube is connected to the second power supply end; A reverse blocking controller, wherein the third control end of the reverse blocking controller is connected to the control end of the switch tube, and the reverse blocking controller is used to control the third switch tube to be turned on when the first voltage is less than or equal to the second voltage, so as to control the first transformer module to be turned off.

9. The voltage conversion circuit according to claim 1, characterized in that: The second voltage transformation module includes at least one switching transistor; the switching transistor includes a body diode; The filtering module comprises: a capacitor connected between the output end of the first transformer module and / or the output end of the second transformer module and the output end of the voltage conversion circuit; Alternatively, the filtering module includes: an inductor and a capacitor, the first end of the inductor is connected to the output end of the first transformer module and / or the output end of the second transformer module, the second end of the inductor is connected to the first end of the capacitor and the output end of the voltage conversion circuit, and the second end of the capacitor is connected to the ground end.

10. A voltage conversion device, characterized in that: include: The voltage conversion circuit according to any one of claims 1 to 9.

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