High-voltage pulse generator based on signal trailing suppression design

Abstract

The invention provides a high-voltage pulse generator based on a signal trailing suppression design, which is characterized by comprising n stages of Marx booster circuits which have the same structure and are connected in sequence, and n is an integer and is greater than or equal to 2; the ith Marx booster circuit comprises a charging current-limiting resistor Ri, a capacitor Ci, a field effect transistor MOSFETi and an ith discharging circuit, and i = 1,..., n; the ith discharge circuit comprises two parallel discharge circuits; the first discharge circuit in the two parallel discharge circuits comprises a discharge current limiting resistor Ri + n and a field effect transistor MOSFETi + n; the second discharging circuit in the two parallel discharging circuits comprises a discharging current-limiting resistor Ri + 2n and a field effect transistor MOSFET (Metal Oxide Semiconductor Field Effect Transistor) i + 2n; and the discharge current-limiting resistor Ri + n and the discharge current-limiting resistor Ri + 2n have different resistance values. According to the high-voltage pulse generator provided by the invention, rapid discharge can be realized by controlling the on-off of the field effect transistor MOSFET, the falling edge is further shortened, and high-voltage pulses with narrower pulse width are generated while the type selection limitation on resistors and switching devices is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of high-voltage pulse, and particularly relates to a high-voltage pulse generator based on signal tailing inhibition design. BACKGROUND

[0002] The high-voltage pulse generator refers to a special pulse signal generator capable of outputting a pulse amplitude of 1kV or above, and is generally used in the fields of pulse power, electromagnetic compatibility test, semiconductor test and the like. The high-voltage pulse signal generated by the high-voltage pulse generator includes multiple waveform characteristic parameters such as pulse amplitude, rise time, fall time and pulse width. The pulse width determines the action time of the signal, and the rise time and the fall time are the definition of the pulse width. When the pulse is used as a trigger signal, there is often an electrical signal threshold, above which the trigger is triggered, and below which the trigger is closed. In the application scenario with high requirements for the pulse width, the rise time and the fall time have an important influence on the high-frequency trigger of the pulse signal. As for the falling edge, if the fall time is long, that is, the pulse signal takes a long time to consume from the full amplitude to the closing threshold, which will seriously affect the time interval of the next trigger, thereby greatly limiting the high-repetition-frequency application of the pulse trigger.

[0003] The prior art proposes a way of adding a group of MOS tubes and discharge resistors in the traditional Marx structure to open the MOS tube for a period of time after the high-voltage forming discharge stage is over, so as to realize the rapid release of the high-voltage capacitor voltage, thereby reducing the waveform falling tail, and effectively shortening the high-voltage pulse width. However, with this design, the pulse fall time is still long, and the tailing phenomenon still exists, which limits the further reduction of the pulse width and still affects the generation of the high-repetition-frequency pulse square wave.

[0004] In view of the above problems, it is urgent to provide a new high-voltage pulse generator to solve the problem of long pulse fall time and tailing phenomenon limiting the generation of high-repetition-frequency pulse square wave in the prior art. SUMMARY

[0005] Therefore, the application provides a high-voltage pulse generator capable of inhibiting signal tailing phenomenon and further reducing the pulse width of high-repetition-frequency pulse square wave.

[0006] To achieve the above purpose, the application adopts the following technical solutions:

[0007] The high-voltage pulse generator based on signal tailing inhibition design comprises n-stage Marx voltage boosting circuits which are the same in structure and connected in sequence, and n is an integer and n≥2; the i-th stage Marx voltage boosting circuit comprises a charging current limiting resistor R i , a capacitor C i , a field effect transistor MOSFET i , and an i-th discharge circuit, i=1,......,n.

[0008] The first i discharge circuit includes two parallel discharge circuits; the first of the two parallel discharge circuits includes a discharge current-limiting resistor R i+n and a field effect transistor MOSFET i+n ; the second of the two parallel discharge circuits includes a discharge current-limiting resistor R i+2n and a field effect transistor MOSFET i+2n ; the discharge current-limiting resistor R i+n and the discharge current-limiting resistor R i+2n have different resistance values.

[0009] Preferably, the high-voltage pulse generator designed based on signal tail suppression further includes an output voltage monitoring circuit; the high-voltage pulse generator switches the two parallel discharge circuits of the discharge circuit according to the monitoring voltage of the output voltage monitoring circuit.

[0010] Preferably, the output voltage monitoring circuit includes a high-voltage forming resistor R 3n+1 connected in series at the high-voltage output end, and a voltage dividing resistor R 3n+2 connected in parallel to the high-voltage forming resistor, wherein the output voltage amplitude of the high-voltage pulse generator is embodied at the two ends of the high-voltage forming resistor and is divided by the voltage dividing resistor to obtain a sampling voltage V out for monitoring the output voltage V D .

[0011] Preferably, the discharge current-limiting resistor R i+n and the discharge current-limiting resistor R i+2n both work in the rated power range.

[0012] Preferably, the discharge current-limiting resistor R i+n is greater than the discharge current-limiting resistor R i+2n .

[0013] Preferably, the discharge current-limiting resistor R i+n is k times the discharge current-limiting resistor R i+2n , 1 < k ≤ 100.

[0014] Preferably, the resistance value of the discharge current-limiting resistor R i+n is 100Ω-10kΩ.

[0015] Preferably, the resistance values of the discharge current-limiting resistors R i+2n of each stage of the Marx voltage boosting circuit are not completely the same.

[0016] The beneficial effects of the present application are: the high-voltage pulse generator based on signal tailing suppression design of the present application is suitable for a wide magnitude from kV to hundreds of kV, can shorten the pulse width of the high-voltage pulse by more than one time, effectively solves the problem of long falling time and serious tailing of the high-voltage pulse waveform under the premise of not changing the discharge time, makes the high-voltage pulse waveform more complete, and provides a basis for generating high-frequency pulse square waves. The truncated loop design provided by the present application can shorten the falling edge by controlling the on-off of the MOSFET, and at the same time, generate a high-voltage pulse with a narrower pulse width while reducing the selection limitation of the resistance and switching device. In addition, in order to better adapt to the voltage resistance and rated power requirements of the MOSFET and resistance of the small resistance discharge circuit, the output voltage monitoring circuit is introduced to realize the switching of the small resistance circuit, thereby improving the safety of the device use; further, the small resistance circuit is controlled by the way of connecting a small resistance voltage divider in series with the pulse forming resistance to monitor the amplitude of the high-voltage pulse, which is more convenient for voltage sampling and circuit control. Further, the resistance value of the small resistance discharge circuit is also provided, which can ensure the safe operation of the small resistance within the rated condition range while shortening the discharge time, and also reduces the limitation of the voltage resistance of the MOSFET. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 Technical framework of the embodiment of the present application

[0018] Figure 2 Circuit schematic diagram of the embodiment of the present application

[0019] Figure 3 Small resistance circuit discharge electric pulse waveform diagram of the embodiment of the present application DETAILED DESCRIPTION

[0020] The present application is described below based on the embodiments, but the present application is not limited to only these embodiments. In the following detailed description of the present application, some specific details are described in detail. The present application can also be completely understood without the description of these details. In order to avoid confusion of the essence of the present application, the well-known methods, processes, flows, elements are not described in detail.

[0021] The following refers to Figures 1 to 3 The embodiments of the high-voltage pulse generator based on signal tailing suppression design of the present application are described.

[0022] A high-voltage pulse generator based on signal tailing suppression design, comprising n-stage Marx voltage boosting circuits with the same structure and connected in sequence, n is an integer and n≥2; the i-th stage Marx voltage boosting circuit comprises a charging current limiting resistor R i , a capacitor C i , a field effect transistor MOSFETi , and the i-th discharge circuit, i = 1,..., n;

[0023] The i-th discharge circuit comprises two parallel discharge circuits; the first of the two parallel discharge circuits comprises a discharge current-limiting resistor R i+n and a field effect transistor MOSFET i+n ; the second of the two parallel discharge circuits comprises a discharge current-limiting resistor R i+2n and a field effect transistor MOSFET i+2n ; the discharge current-limiting resistor R i+n and the discharge current-limiting resistor R i+2n have different resistance values.

[0024] The working principle of the embodiment of the present application is shown in Figure 1 After the high-voltage input multi-stage Marx structure is boosted, the high-voltage capacitor is fully charged, and the conduction and turn-off of the field effect transistor controlled by the MCU forms a high-voltage signal across the resistance (usually a super-large resistance) for high-voltage shaping; the loop with a larger discharge resistor in the i-th discharge circuit is referred to as a high-voltage large-resistance loop, and the loop with a smaller discharge resistor in the i-th discharge circuit is referred to as a low-voltage small-resistance loop; after the high-voltage shaping for a certain time (a specified pulse width), the conduction and turn-off of the field effect transistor is controlled to turn on each high-voltage large-resistance loop to perform the first step of discharge; the high-voltage superimposed by the multi-stage Marx structure starts to discharge to form a falling edge; the high-voltage large-resistance loop discharge time τ H is determined by the product of the high-voltage capacitor C and the discharge loop resistor R H , that is:

[0025] τ H = C x R H (1)

[0026] wherein R H refers to the sum of the discharge resistors of the high-voltage large-resistance loops of each Marx loop.

[0027] After the first step of discharge, the conduction and turn-off of the field effect transistor is controlled to turn off each high-voltage large-resistance loop and turn on each low-voltage small-resistance loop to perform the second step of discharge; the low-voltage small-resistance loop discharge time τ L is also:

[0028] τ L = C x R L (2)

[0029] wherein R L refers to the sum of the discharge resistors of the low-voltage small-resistance loops of each Marx loop.

[0030] Since the amplitude of the high voltage signal is as high as tens of kV, the resistance of the power resistor that can work under this condition cannot be too small, thus, compared with formula (1), formula (2) is obtained by changing the resistance from R H to R L , the discharge time can be further shortened greatly, and the waveform has a shorter falling edge and pulse width.

[0031] Further, as shown in Figure 1 , the switching of the high-voltage large-resistance circuit and the low-voltage small-resistance circuit can be realized in various ways, such as software delay or monitoring voltage of the voltage dividing resistor.

[0032] In a preferred embodiment, the high-voltage pulse generator designed based on signal tail suppression further comprises an output voltage monitoring circuit; the high-voltage pulse generator switches the two parallel discharge circuits of the discharge circuit according to the monitoring voltage of the output voltage monitoring circuit.

[0033] In a preferred embodiment, the output voltage monitoring circuit comprises: a high-voltage shaping resistor R 3n+1 and a voltage dividing resistor R 3n+2 connected in series at the high-voltage output end, the amplitude of the output voltage of the high-voltage pulse generator is embodied at the two ends of the high-voltage shaping resistor and is divided by the voltage dividing resistor to obtain a sampling voltage V out for monitoring the output voltage V D .

[0034] In a preferred embodiment, the discharge current limiting resistor R i+n and the discharge current limiting resistor R i+2n work in the rated power range.

[0035] In a preferred embodiment, the discharge current limiting resistor R i+n is greater than the discharge current limiting resistor R i+2n .

[0036] In a preferred embodiment, the discharge current limiting resistor R i+n is k times the discharge current limiting resistor R i+2n , 1 < k ≤ 100.

[0037] In a preferred embodiment, the resistance of the discharge current limiting resistor R i+n is 100 Ω to 10 kΩ.

[0038] In a preferred embodiment, the resistances of the discharge current limiting resistors R i+2n of the Marx voltage boosting circuits at different levels are not completely the same.

[0039] In a more specific embodiment, as shown in Figure 2The high-voltage input of the high-voltage pulse generator designed based on signal tailing suppression is 4kV, the Marx structure is 6 stages (n=6), the charging current limiting resistor R i of each stage of the Marx voltage boosting circuit is 100kΩ, the capacitor C i is 0.1μF / 4kV, the first of the two parallel discharge circuits in the ith discharge circuit is a high-voltage large resistance circuit (discharge current limiting resistor R i+n and field effect transistor MOSFET i+n ), the second of the two parallel discharge circuits in the ith discharge circuit is a low-voltage small resistance circuit (discharge current limiting resistor R i+2n and field effect transistor MOSFET i+2n ); a small resistance R 19 is connected in series with the high-voltage forming resistor R 20 as a voltage dividing resistor for detecting the discharge voltage, and the specific working steps are as follows: when the high-voltage pulse signal starts to discharge, the high-voltage large resistance circuit (red loop) composed of large resistors R7-R12 is first controlled by MOSFET7-MOSFET12 to discharge the high-voltage in the first step, and the voltage amplitude is reflected on the forming resistor R19 and is divided by R20 to obtain a small voltage for monitoring sampling; when the high-voltage decreases to the range of the small resistance voltage resistance (rated power), the high-voltage large resistance circuit (red loop) is turned off and the low-voltage small resistance circuit (green loop) is turned on, i.e. MOSFET7-MOSFET12 are turned on, and the low-voltage signal is discharged faster through the small resistance R13-R18 loop. Since the capacitance of the high-voltage capacitor C is unchanged, the resistance changes from R H (kilo-ohm level) to R L (ten-ohm level), which can further greatly shorten the discharge time, and the ideal waveform is as shown in Figure 3 Compared with the single truncated loop discharge waveform (blue waveform) on the top: after adding the small resistance discharge loop, the discharge can be faster when the voltage decreases to a certain amplitude, so that the waveform has a shorter falling edge and pulse width.

[0040] Since each stage of the Marx voltage boosting circuit is provided with a discharge circuit, this method is not limited by the number of Marx stages, and due to the effect of series voltage division, the resistance values of the discharge resistors of each stage can also be flexibly adjusted. For example, for a 6-stage Marx structure, the 6th stage uses 500Ω, and the other 5 stages use 10Ω. At this time, the total voltage division of the other 5 stages is only one tenth of the 6th stage. This not only shortens the discharge time, but also more safely ensures that the small resistors of the other 5 stages work within the rated condition range. Similarly, this circuit also reduces the limitation on the voltage resistance value of MOSFET.

[0041] The beneficial effects of this invention are as follows: The high-voltage pulse generator based on signal tail suppression design is applicable to a wide voltage range from kV to hundreds of kV. It can shorten the pulse width of the high-voltage pulse by more than half, effectively solving the problems of long fall time and severe tailing of the high-voltage pulse waveform without changing the discharge time. This results in a more complete high-voltage pulse waveform and provides a basis for generating high-repetition-rate pulse square waves. The truncated circuit design provided by this invention can further shorten the fall edge by controlling the switching of the MOSFET to achieve rapid discharge, reducing the limitations on the selection of resistors and switching devices while generating a narrower pulse width high-voltage pulse. In addition, to better adapt to the withstand voltage and rated power requirements of the MOSFET and resistor in the small-resistance discharge circuit, an output voltage monitoring circuit is introduced to realize the switching of the small-resistance circuit, thereby improving the safety of device use. Furthermore, a method of controlling the switching of the small-resistance circuit by monitoring the high-voltage pulse amplitude through a small resistor in series next to the pulse shaping resistor is designed, which facilitates voltage sampling and circuit control. Furthermore, it provides a design for the resistance value of the small-resistance discharge circuit, which can ensure that the small resistor operates within the rated conditions more safely while shortening the discharge time. Similarly, it also reduces the limitation on the MOSFET's withstand voltage value.

Claims

1. A high-voltage pulse generator based on signal tail suppression design, characterized in that, It includes n identical Marx boost circuits connected sequentially, where n is an integer and n≥2; the i-th Marx boost circuit includes a charging current-limiting resistor R. i Capacitor C i MOSFET (Metal-O-Field Transistor) i And the i-th discharge circuit, i = 1, ..., n; The i-th discharge circuit includes two parallel discharge circuits; the first of the two parallel discharge circuits includes a discharge current-limiting resistor R. i+n and field-effect transistors (MOSFETs) i+n The second of the two parallel discharge circuits includes a discharge current-limiting resistor R. i+2n and field-effect transistors (MOSFETs) i+2n The discharge current limiting resistor R i+n and discharge current limiting resistor R i+2n They have different resistance values.

2. A high-voltage pulse generator based on signal tail suppression design according to claim 1, characterized in that, It also includes an output voltage monitoring circuit; the high-voltage pulse generator switches between the two parallel discharge circuits of the discharge circuit according to the monitoring voltage of the output voltage monitoring circuit.

3. A high-voltage pulse generator based on signal tail suppression design according to claim 1, characterized in that, The output voltage monitoring circuit includes: a high-voltage shaping resistor R connected in series at the high-voltage output terminal. 3n+1 The voltage divider resistor R next to it 3n+2 The output voltage amplitude of the high-voltage pulse generator is reflected across the high-voltage forming resistor and then divided by a voltage divider resistor to obtain the output voltage V used for monitoring. out Sampling voltage V D .

4. A high-voltage pulse generator based on signal tail suppression design according to claim 1, characterized in that, The discharge current limiting resistor R i+n and the discharge current limiting resistor R i+2n All operate within their rated power range.

5. A high-voltage pulse generator based on signal tail suppression design according to claim 1, characterized in that, The discharge current limiting resistor R i+n Greater than the discharge current limiting resistor R i+2n .

6. A high-voltage pulse generator based on signal tail suppression design according to claim 1, characterized in that, The discharge current limiting resistor R i+n The discharge current limiting resistor R is i+2n k times, 1 <k≤100。 7. A high-voltage pulse generator based on signal tail suppression design according to claim 1, characterized in that, The discharge current limiting resistor R i+n The resistance is 100Ω to 10kΩ.

8. A high-voltage pulse generator based on signal tail suppression design according to claim 1, characterized in that, Discharge current limiting resistor R in each stage of the Marx boost circuit i+2n The resistance values ​​are not exactly the same.

Images