CN219627566U - 0-6 kV adjustable precision DC-DC converter - Google Patents

Abstract

The utility model relates to a 0-6 kV adjustable precision DC-DC converter, which comprises a shell and a conversion circuit, wherein the conversion circuit comprises an input protection circuit, an input filter circuit, an oscillation boosting circuit, a voltage doubling circuit and an output filter circuit which are sequentially connected, the input filter circuit and the input protection circuit are connected with a power input terminal of the DC-DC converter, and the output filter circuit is connected with a high-voltage output terminal of the DC-DC converter. The conversion circuit also comprises a sampling circuit, an output protection circuit and a control circuit. The DC-DC converter can reduce the volume of a high-voltage power supply module, simplify the structure of the high-voltage power supply module, improve the modularization degree of the high-voltage power supply module, and strengthen the overcurrent and overvoltage protection, so that the working stability of the high-voltage power supply is improved, the maintenance difficulty of the high-voltage power supply is reduced, and the use cost of the high-voltage power supply module is reduced.

Description

0-6 kV adjustable precision DC-DC converter

Technical Field

The utility model relates to the technical field of DC-DC converters, in particular to a 0-6 kV adjustable precision DC-DC converter.

Background

The DC-DC converter is a voltage converter that converts an input direct-current voltage into an output direct-current voltage. According to the difference of the level relationship between the input direct current voltage and the output direct current voltage, the DC/DC converter is classified into three types: step-up DC-DC converter, step-down DC-DC converter, and step-up DC-DC converter. At present, the DC-DC converter is widely applied to products such as automobiles, computers, mobile phones, displays, digital cameras, portable media players and the like.

The DC-DC converter may be used as a high voltage power module to provide a continuously adjustable DC high voltage output for a load in the range of 0V to ±6000V. Most of the boosting high-voltage power supply modules with the same voltage level in the prior art are large in size, complex in structure, low in modularization degree, imperfect in overcurrent and overvoltage protection, low in working stability, high in maintenance difficulty and high in use cost.

Disclosure of Invention

In order to solve one or more of the technical problems in the prior art, the utility model provides the 0-6 kV adjustable precision DC-DC converter, which is used for reducing the volume of a high-voltage power supply module, simplifying the structure of the high-voltage power supply module, improving the modularization degree of the high-voltage power supply module, adopting high-precision components for key circuits, improving the precision of the high-voltage power supply, enhancing the overcurrent and overvoltage protection, improving the working stability of the high-voltage power supply, reducing the maintenance difficulty of the high-voltage power supply module and reducing the use cost of the high-voltage power supply module.

The utility model provides a 0-6 kV adjustable precision DC-DC converter, which comprises a shell and a conversion circuit, wherein the conversion circuit comprises an input protection circuit, an input filter circuit, an oscillation boosting circuit, a voltage doubling circuit and an output filter circuit which are sequentially connected, the input protection circuit and the input filter circuit are connected with a power input terminal of the DC-DC converter, and the output filter circuit is connected with a high-voltage output terminal of the DC-DC converter; the conversion circuit further comprises a sampling circuit, an output protection circuit and a control circuit, wherein the sampling circuit comprises a voltage sampling circuit and a current sampling circuit, the voltage sampling circuit collects output voltage signals of the DC-DC converter and outputs the output voltage signals to a voltage sampling output terminal of the DC-DC converter, and the current sampling circuit collects output current signals of the DC-DC converter and outputs the output current signals to a current sampling output terminal of the DC-DC converter; the input end of the output protection circuit is connected with the output end of the sampling circuit, and an output end signal is sent into the control circuit so as to prevent the damage caused by overlarge voltage or current of the DC-DC converter; the control circuit is connected with the oscillation boosting circuit to control the switching frequency of the oscillation boosting circuit.

In one embodiment, the input filter circuit comprises a first inductor and a first capacitor, wherein the first inductor is connected with a positive power input terminal of the DC-DC converter, the other end of the first inductor is connected with the first capacitor, the connection point of the first inductor is an output end of the input filter circuit, and the other end of the first capacitor is grounded.

In one embodiment, the input protection circuit includes a first resistor, a first field effect transistor, a first reference cell, a second reference cell, a first comparator, a second comparator, and a first logic cell. The first resistor is connected with a positive power input terminal of the DC-DC converter and is also input into an inverting input end of the first comparator and a non-inverting input end of the second comparator; the grid electrode of the first field effect transistor is connected with the other end of the first resistor, the drain electrode of the first field effect transistor is connected with the power input negative terminal of the DC-DC converter, and the source electrode of the first field effect transistor is grounded; the first reference unit and the second reference unit are respectively input into the non-inverting input end of the first comparator and the inverting input end of the second comparator; the output ends of the first comparator and the second comparator are connected with the input end of the first logic unit, and the output end of the first logic unit is the output end of the input protection circuit.

In one embodiment, the oscillation boosting circuit is a single-ended reaction type oscillation circuit and comprises a second field effect transistor and a boosting transformer, wherein one end of a primary coil of the boosting transformer is connected with the output end of the input filter circuit, and the other end of the primary coil of the boosting transformer is connected with the drain electrode of the second field effect transistor; the grid electrode of the second field effect tube is connected with the output of the control circuit, and the source electrode of the second field effect tube is grounded; the secondary winding of the step-up transformer serves as the output end of the step-up transformer.

In one embodiment, the voltage doubling circuit is a six-stage voltage doubling circuit, and comprises second to seventh capacitors and first to sixth diodes, wherein each stage of voltage doubling circuit comprises one capacitor and one diode which are connected in series, and then the capacitors and the diodes are connected in series according to the principle of polarity addition so as to achieve the purpose of voltage doubling, the first stage of voltage doubling circuit is connected with the secondary coil of the step-up transformer so as to input the boosted voltage, the six-stage voltage doubling circuit outputs six-stage voltage doubling voltage, and the polarities of the diodes in the voltage doubling circuit can be correspondingly adjusted according to the polarities of the output voltage of the DC-DC converter.

In one embodiment, the output filter circuit includes a second resistor, a third resistor, a fourth resistor, an eighth capacitor, and a ninth capacitor, wherein the second resistor, the third resistor, and the fourth resistor are connected in series, one end of the second resistor is connected to the output terminal of the voltage doubling circuit, one end of the fourth resistor is connected to the high voltage output terminal of the DC-DC converter, one end of the eighth capacitor is connected to a series node of the second resistor and the third resistor, the other end is connected to a virtual ground of the secondary winding of the step-up transformer, one end of the ninth capacitor is connected to a series node of the third resistor and the fourth resistor, and the other end is connected to the high voltage output terminal of the DC-DC converter.

In one embodiment, the sampling circuit includes two parts, voltage sampling and current sampling. The voltage sampling circuit includes a first operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, and a tenth capacitor. One end of the fifth resistor is connected with the output end of the output filter circuit, the other end of the fifth resistor is connected with one end of the sixth resistor, a node of the fifth resistor is input to the non-inverting input end of the first operational amplifier, and the other end of the sixth resistor is grounded; one end of the seventh resistor is connected with the inverting input end of the first operational amplifier, and the other end of the seventh resistor is grounded; the tenth capacitor is connected with the inverting input end and the output end of the first operational amplifier, and the output end of the first operational amplifier is connected with the voltage sampling output terminal of the DC-DC converter. The current sampling circuit includes a second operational amplifier, an eighth resistor, a ninth resistor, a tenth resistor, and an eleventh capacitor. One ends of the eighth resistor and the ninth resistor are connected, a node is connected with one end of a virtual ground of a secondary coil of the step-up transformer, the other end of the eighth resistor is grounded, the other end of the ninth resistor is connected with an inverting input end of the second operational amplifier, one end of the tenth resistor is connected with a non-inverting input end of the second operational amplifier, the other end of the tenth resistor is grounded, the eleventh capacitor is connected with the inverting input end and the output end of the second operational amplifier, and the output end of the second operational amplifier is connected with a current sampling output terminal of the DC-DC converter.

In one embodiment, the output protection circuit includes a second logic unit, a third reference unit, a third operational amplifier, and a twelfth capacitor. The input end of the second logic unit is connected with the output end of the voltage and current sampling circuit, the output end of the second logic unit is connected with the non-inverting input end of the third operational amplifier, the third reference unit is connected with the inverting input end of the third operational amplifier, and the twelfth capacitor is connected with the inverting input end and the output end of the third operational amplifier.

In one embodiment, the control circuit includes a control chip and its peripheral circuits, and the input terminal of the control circuit includes: the output of the input protection circuit, the output of the output protection circuit and the voltage regulation input terminal Vadj of the DC-DC converter. And the output end Vref of the control circuit is connected with the reference voltage output terminal of the DC-DC converter, and the Ctrl end is connected with the grid electrode of the second field effect transistor in the oscillation boosting circuit.

In one embodiment, the input voltage range of the DC-DC converter is 11-16V or 21-28V, and the output voltage range is 0V to + -6000V.

The technical scheme of the utility model has the following beneficial technical effects:

the DC-DC converter adopts microminiature components and adopts the functional partition modularization layout, so that the volume of the high-voltage power supply module is reduced, the structure is simple, the modularization degree is high, and the input and output protection is enhanced, thereby improving the working stability of the high-voltage power supply, being easy to maintain and repair and reducing the use cost.

Drawings

The above, as well as additional purposes, features, and advantages of exemplary embodiments of the present utility model will become readily apparent from the following detailed description when read in conjunction with the accompanying drawings. In the drawings, embodiments of the utility model are illustrated by way of example and not by way of limitation, and like reference numerals refer to similar or corresponding parts and in which:

fig. 1 is a schematic configuration diagram of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model;

fig. 2 is a circuit schematic of an input filter circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model;

fig. 3 is a circuit schematic of an input protection circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model;

fig. 4 is a circuit schematic of an oscillating boost circuit of a conversion circuit of a DC-DC converter according to an embodiment of the utility model;

fig. 5 is a circuit schematic of a voltage doubling circuit of a conversion circuit of a DC-DC converter according to an embodiment of the utility model;

fig. 6 is a circuit schematic of an output filter circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model;

fig. 7 is a circuit schematic of a voltage sampling circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model;

fig. 8 is a circuit schematic of a current sampling circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model;

fig. 9 is a circuit schematic of an output protection circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model;

fig. 10 is a schematic structural diagram of a control circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be understood that when the terms "first," "second," and the like are used in the claims, the specification and the drawings of the present utility model, they are used merely for distinguishing between different objects and not for describing a particular sequential order. All the drawings and the description are only for the case where the high voltage output is positive voltage, and the case where the high voltage output is negative voltage is slightly adjusted internally, and will not be described here. The terms "comprises" and "comprising" when used in the specification and claims of the present utility model are taken to specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The utility model provides a 0-6 kV adjustable precision DC-DC converter which comprises a shell and a conversion circuit. Fig. 1 is a schematic configuration diagram of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 1, the conversion circuit includes an input protection circuit, an input filter circuit, an oscillation boosting circuit, a voltage doubling circuit, and an output filter circuit which are sequentially connected, wherein the input filter circuit and the input protection circuit are connected to a power input terminal of the DC-DC converter, and the output filter circuit is connected to a high voltage output terminal of the DC-DC converter. The conversion circuit also comprises a sampling circuit, an output protection circuit and a control circuit. The sampling circuit comprises voltage sampling and current sampling, and is used for collecting output voltage and current signals of the DC-DC converter and outputting the output voltage and current signals through a voltage sampling terminal and a current sampling terminal of the DC-DC converter; the output protection circuit is used for preventing damage caused by too large output voltage and current of the DC-DC converter; the control circuit is mainly used for controlling the switching frequency of the DC-DC converter to enable the DC-DC converter to work normally.

Fig. 2 is a circuit schematic of an input filter circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 2, the input filter circuit includes a first inductor L1 and a first capacitor C1, where the first inductor L1 is connected with the first capacitor C1 to form an LC filter circuit, and is connected to a power input terminal of the DC-DC converter to filter an ac component in an input DC voltage signal, and output a filtered voltage Vf after passing through the LC filter circuit.

Fig. 3 is a circuit schematic of an input protection circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 3, the input protection circuit includes a first resistor R1, a first field effect transistor Q1, a first reference cell V1, a second reference cell V2, a first comparator O1, a second comparator O2, and a first logic cell S1. The drain electrode and the source electrode of the first field effect transistor Q1 are respectively connected with the negative power input end of the DC-DC converter and the ground wire inside the conversion circuit, the positive power input end of the DC-DC converter controls the grid electrode of the first field effect transistor Q1 through the first resistor R1 to prevent reverse connection of an input power supply, meanwhile, the reverse phase or in-phase input ends of the first comparator O1 and the second comparator O2 are also input, the other input ends of the first comparator O1 and the second comparator O2 are respectively connected with the first reference unit V1 and the second reference unit V2, and the first reference unit V1 and the second reference unit V2 are compared with the input voltage, and the first reference unit V1 and the second reference unit V2 are output to the control circuit inside the DC-DC converter through the logic unit S1 when overvoltage or undervoltage faults occur.

Fig. 4 is a circuit schematic of an oscillating boost circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 4, the oscillating circuit is a single-ended counterattack oscillating circuit, and includes a second field effect transistor Q2 and a step-up transformer T1, where one end of a primary coil of the step-up transformer is connected to an output end Vf of the input filter circuit, and the other end is connected to a drain of the second field effect transistor Q2; the source electrode of the second field effect transistor Q2 is grounded, and the grid electrode is connected with the Ctrl output end of the control circuit so as to control the high-voltage output by adjusting the switching frequency of the Q2; the secondary winding of the step-up transformer serves as the output terminals Vr and Vg of the step-up transformer.

Fig. 5 is a circuit schematic of a voltage doubler circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 5, the voltage doubling circuit is a six-stage voltage doubling circuit, wherein each stage of voltage doubling circuit comprises a capacitor and a diode which are connected in series, and then the capacitor and the diode are connected in series according to the principle of polarity addition so as to achieve the purpose of voltage doubling, the first stage of voltage doubling circuit is connected with the Vr end of the secondary coil of the step-up transformer so as to input the boosted voltage, and the six-stage voltage doubling circuit outputs a six-voltage Vm. The voltage doubler circuit amplifies by discharging the switch of the diode and the capacitor. In this embodiment, the voltage doubling circuit is a six-voltage doubling circuit, and outputs a positive voltage. It should be understood that the voltage doubling circuit may be other voltage doubling circuits, such as a voltage doubling circuit, depending on the magnitude of the desired output voltage; the output may be a negative voltage, and the diode direction may be adjusted, which is not particularly limited in the present utility model.

Fig. 6 is a circuit schematic of an output filter circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 6, the output filter circuit includes a second resistor R2, a third resistor R3, a fourth resistor R4, an eighth capacitor C8, and a ninth capacitor C9. The second resistor R2 and the eighth capacitor C8 form an RC first stage filter circuit connected to the output terminals Vm and Vg of the voltage doubling circuit, and the third resistor R3, the fourth resistor R4 and the ninth capacitor C9 form an RCR second stage filter circuit connected to the high voltage output terminal of the DC-DC converter. The output filter circuit is used for filtering alternating current components of the high-voltage signals.

Fig. 7 is a circuit schematic of a voltage sampling circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 7, the voltage sampling circuit includes a first operational amplifier U1, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and a tenth capacitor C10. The fifth resistor R5 and the sixth resistor R6 divide the voltage and sample the high voltage output voltage Vout, and then input the sampled voltage to the non-inverting input terminal of the first operational amplifier U1, the inverting input terminal of the first operational amplifier U1 is grounded through the seventh resistor R7, the tenth capacitor C10 is connected to the inverting input terminal and the output terminal of the first operational amplifier U1 to form feedback, and the output terminal Vs of the first operational amplifier U1 outputs a voltage sampling signal through the voltage sampling output terminal Vmon of the DC-DC converter and also inputs the voltage sampling signal to the output protection circuit.

Fig. 8 is a circuit schematic of a current sampling circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 8, the current sampling circuit includes a second operational amplifier U2, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and an eleventh capacitor C11. After the eighth resistor R8 Is connected to the Vg end of the secondary winding of the step-up transformer to sample the current, the current Is input to the inverting input end of the second operational amplifier U2 through the ninth resistor R9, the non-inverting input end of the second operational amplifier U2 Is grounded through the tenth resistor R10, the eleventh capacitor C11 Is connected to the inverting input end and the output end of the second operational amplifier U2 to form feedback, and the output end Is of the second operational amplifier U2 outputs a current sampling signal through the current sampling output terminal Imon of the DC-DC converter and Is also input to the output protection circuit.

Fig. 9 is a circuit schematic of an output protection circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 9, the output protection circuit includes a second logic unit S2, a third reference unit V3, a third operational amplifier U3, and a twelfth capacitor C12. The input end of the second logic S2 unit Is connected with the output ends Vs and Is of the voltage and current sampling circuit, and sends the voltage and current sampling circuit to the non-inverting input end of the third operational amplifier U3, the third reference unit V3 sends the set reference signal to the inverting input end of the third operational amplifier U3, the twelfth capacitor C12 Is connected with the inverting input end and the output end of the third operational amplifier U3 to form feedback, and the protection signal Vpo Is output after processing and sent to the control circuit. To prevent damage caused by excessive output voltage or current of the DC-DC converter.

Fig. 10 is a schematic structural diagram of a control circuit of a conversion circuit of a DC-DC converter according to an embodiment of the present utility model. As shown in fig. 10, the control circuit includes a control chip and its peripheral circuits, and the input signals include an input protection signal Vpi, an output protection signal Vpo, and an externally input voltage adjustment signal Vadj, so as to perform receiving processing on the protection signal and the user. The output signal has a reference voltage Vref sent to the outside for a user to adjust and output high voltage; in addition, a control signal Ctrl is connected to the gate of the second field effect transistor Q2 in the oscillating boost circuit to control the switching frequency of the oscillating boost circuit, thereby adjusting the output result to achieve the user setting target and protecting the DC-DC converter itself.

In one embodiment, the input voltage range of the DC-DC converter is 11-16V or 21-28V, and the output voltage range is 0V to + -6000V. The output voltage is adjustable in the range of the output voltage, and a user can adjust the amplitude of the output high voltage through two modes of voltage adjustment or potentiometer adjustment.

In one embodiment, the housing is an all-metal shielding structure, and the housing has an external dimension of 76×64×24mm and a weight of less than 300 g. The metal shell may be a copper shell or an aluminum shell. All outgoing lines of the DC-DC converter are high-voltage silica gel wires. The interior of the conversion circuit adopts microminiature components, adopts SMT technology welding, controls and drives regional welding, and has reasonable structural layout, thereby reducing the volume of the converter.

In one embodiment, the interior of the housing is filled with a high pressure resistant, thermally conductive adhesive to expedite the dissipation of heat generated during operation of the conversion circuit.

In one embodiment, the terminal leads of the DC-DC converter are high-voltage silica gel color leads, so that high insulation and high voltage resistance, low loss and easy identification of the terminal leads are ensured.

The structure of the DC-DC converter of the present utility model is described in detail above by means of specific embodiments. In the use process, the input voltage is subjected to filtering treatment and then the oscillation frequency is controlled by the control circuit, then the input voltage is subjected to boosting voltage doubling circuit and then the output high voltage is output, and finally the output is obtained after the filtering treatment is performed again. Meanwhile, the output high voltage is fed back to the control loop through the sampling circuit so as to obtain stable output and provide a sampling data output function. In addition, the DC-DC converter is provided with an input and output protection circuit to prevent reverse connection, undervoltage or overvoltage of the input and provide overcurrent and overvoltage protection functions.

The DC-DC converter adopts microminiature components and adopts a modularized welding mode, so that the volume of the high-voltage power supply module is reduced, the structure is simple, the modularization degree is high, the key components adopt high-precision components, and the precision of the high-voltage power supply is improved, thereby improving the working stability of the high-voltage power supply, being easy to maintain and repair and reducing the use cost.

It will be further understood by those skilled in the art from the foregoing description of the present specification that terms such as "upper," "lower," and the like, which indicate an orientation or a positional relationship, are based on the orientation or positional relationship shown in the drawings of the present specification, are for convenience only in describing aspects of the present utility model and simplifying the description, and do not explicitly or implicitly refer to devices or elements that must have the particular orientation, be constructed and operated in the particular orientation, and thus the above orientation or positional relationship terms should not be interpreted or construed as limiting aspects of the present utility model.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims (10)

1. The 0-6 kV adjustable precision DC-DC converter comprises a shell and a conversion circuit, and is characterized in that the conversion circuit comprises an input protection circuit, an input filter circuit, an oscillation boosting circuit, a voltage doubling circuit and an output filter circuit which are sequentially connected, wherein the input protection circuit and the input filter circuit are connected with a power input terminal of the DC-DC converter, and the output filter circuit is connected with a high-voltage output terminal of the DC-DC converter;

the conversion circuit further comprises a sampling circuit, an output protection circuit and a control circuit, wherein the sampling circuit comprises a voltage sampling circuit and a current sampling circuit, the voltage sampling circuit collects output voltage signals of the DC-DC converter and outputs the output voltage signals to a voltage sampling output terminal of the DC-DC converter, and the current sampling circuit collects output current signals of the DC-DC converter and outputs the output current signals to a current sampling output terminal of the DC-DC converter; the input end of the output protection circuit is connected with the output end of the sampling circuit, and an output end signal is sent into the control circuit so as to prevent the damage caused by overlarge voltage or current of the DC-DC converter; the control circuit is connected with the oscillation boosting circuit to control the switching frequency of the oscillation boosting circuit.

2. The 0-6 kV adjustable precision DC-DC converter according to claim 1, wherein the input filter circuit comprises a first inductor and a first capacitor, wherein the first inductor is connected with a positive power input terminal of the DC-DC converter, the other end of the first inductor is connected with the first capacitor, the connection point of the first inductor is an output end of the input filter circuit, and the other end of the first capacitor is grounded.

3. The 0-6 kv adjustable precision DC-DC converter according to claim 1, wherein the input protection circuit comprises a first resistor, a first field effect transistor, a first reference unit, a second reference unit, a first comparator, a second comparator, and a first logic unit, wherein the first resistor is connected to a positive power input terminal of the DC-DC converter, and is also input to an inverting input terminal of the first comparator and a non-inverting input terminal of the second comparator; the grid electrode of the first field effect transistor is connected with the other end of the first resistor, the drain electrode of the first field effect transistor is connected with the power input negative terminal of the DC-DC converter, and the source electrode of the first field effect transistor is grounded; the first reference unit and the second reference unit are respectively input into the non-inverting input end of the first comparator and the inverting input end of the second comparator; the output ends of the first comparator and the second comparator are connected with the input end of the first logic unit, and the output end of the first logic unit is the output end of the input protection circuit.

4. The 0-6 kV adjustable precision DC-DC converter according to claim 1, wherein the oscillation boosting circuit is a single-ended counterattack oscillation circuit and comprises a second field effect transistor and a boosting transformer, wherein one end of a primary coil of the boosting transformer is connected with an output end of the input filter circuit, and the other end of the primary coil of the boosting transformer is connected with a drain electrode of the second field effect transistor; the grid electrode of the second field effect tube is connected with the output of the control circuit, and the source electrode of the second field effect tube is grounded; the secondary winding of the step-up transformer serves as the output end of the step-up transformer.

5. The 0-6 kV adjustable precision DC-DC converter according to claim 4, wherein the voltage doubling circuit is a six-stage voltage doubling circuit comprising second to seventh capacitors and first to sixth diodes, wherein each stage of voltage doubling comprises one capacitor and one diode which are connected in series, and then the voltage doubling circuit is connected in series according to the principle of polarity addition so as to achieve the purpose of voltage doubling, the first stage of voltage doubling circuit is connected with a secondary coil of the step-up transformer so as to input the boosted voltage, and the six-stage voltage doubling circuit outputs six-voltage doubling voltage.

6. The 0-6 kv adjustable precision DC-DC converter according to claim 5, wherein the output filter circuit comprises a second resistor, a third resistor, a fourth resistor, an eighth capacitor, and a ninth capacitor, wherein the second, third, and fourth resistors are connected in series, one end of the second resistor is connected to the output terminal of the voltage doubling circuit, one end of the fourth resistor is connected to the high voltage output terminal of the DC-DC converter, one end of the eighth capacitor is connected to a series node of the second and third resistors, the other end is connected to a virtual ground of the secondary winding of the step-up transformer, one end of the ninth capacitor is connected to a series node of the third and fourth resistors, and the other end is connected to the high voltage output terminal of the DC-DC converter.

7. The 0-6 kV adjustable precision DC-DC converter according to claim 4, wherein the sampling circuit comprises a voltage sampling circuit and a current sampling circuit, the voltage sampling circuit comprises a first operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor and a tenth capacitor, one end of the fifth resistor is connected with the output end of the output filter circuit, the other end of the fifth resistor is connected with one end of the sixth resistor, a node of the sixth resistor is input to the non-inverting input end of the first operational amplifier, and the other end of the sixth resistor is grounded; one end of the seventh resistor is connected with the inverting input end of the first operational amplifier, and the other end of the seventh resistor is grounded; the tenth capacitor is connected with the inverting input end and the output end of the first operational amplifier, and the output end of the first operational amplifier is connected with the voltage sampling output terminal of the DC-DC converter; the current sampling circuit comprises a second operational amplifier, an eighth resistor, a ninth resistor, a tenth resistor and an eleventh capacitor, wherein one ends of the eighth resistor and the ninth resistor are connected, a node is connected with one virtual ground end of a secondary coil of the step-up transformer, the other end of the eighth resistor is grounded, the other end of the ninth resistor is connected with an inverting input end of the second operational amplifier, one end of the tenth resistor is connected with an in-phase input end of the second operational amplifier, the other end of the tenth resistor is grounded, the eleventh capacitor is connected with the inverting input end and the output end of the second operational amplifier, and the output end of the second operational amplifier is connected with a current sampling output terminal of the DC-DC converter.

8. The 0-6 kv adjustable precision DC-DC converter according to claim 1, wherein the output protection circuit comprises a second logic unit, a third reference unit, a third operational amplifier, and a twelfth capacitor, wherein an input end of the second logic unit is connected to an output end of the voltage and current sampling circuit, an output end is connected to a non-inverting input end of the third operational amplifier, the third reference unit is connected to an inverting input end of the third operational amplifier, and the twelfth capacitor is connected to an inverting input end and an output end of the third operational amplifier.

9. The 0-6 kv adjustable precision DC-DC converter according to claim 1, wherein the control circuit includes a control chip and a peripheral circuit thereof, and an input terminal of the control circuit includes: the output end of the input protection circuit, the output end of the output protection circuit and the voltage regulation input terminal Vadj of the DC-DC converter, wherein the output end Vref of the control circuit is connected with the reference voltage output terminal of the DC-DC converter, and the Ctrl end is connected with the grid electrode of the second field effect transistor in the oscillation boosting circuit.

10. The 0-6 kv adjustable precision DC-DC converter according to any one of claims 1 to 9, wherein an input voltage range of the DC-DC converter is 11-16V or 21-28V, and an output voltage range is 0V to ±6000V.