CN107818218B - Nanosecond electromagnetic pulse generator for electromagnetic fault injection - Google Patents
Nanosecond electromagnetic pulse generator for electromagnetic fault injection Download PDFInfo
- Publication number
- CN107818218B CN107818218B CN201711041567.3A CN201711041567A CN107818218B CN 107818218 B CN107818218 B CN 107818218B CN 201711041567 A CN201711041567 A CN 201711041567A CN 107818218 B CN107818218 B CN 107818218B
- Authority
- CN
- China
- Prior art keywords
- electromagnetic
- mosfet
- marx
- circuit
- generator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000002347 injection Methods 0.000 title claims abstract description 14
- 239000007924 injection Substances 0.000 title claims abstract description 14
- 239000000523 sample Substances 0.000 claims abstract description 37
- 230000001052 transient effect Effects 0.000 claims abstract description 20
- 239000003990 capacitor Substances 0.000 claims description 16
- 238000004146 energy storage Methods 0.000 claims description 11
- 230000001629 suppression Effects 0.000 claims description 10
- 238000002955 isolation Methods 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- 230000008859 change Effects 0.000 claims description 3
- 229910000859 α-Fe Inorganic materials 0.000 claims description 3
- 238000013461 design Methods 0.000 abstract description 7
- 238000004519 manufacturing process Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 5
- 238000007599 discharging Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000000630 rising effect Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/30—Circuit design
Abstract
The invention discloses a nanosecond electromagnetic pulse generator for electromagnetic fault injection, which is used for generating a transient electromagnetic pulse signal and belongs to the field of electromagnetic fault injection. The invention mainly comprises a direct current power supply, a signal generator, a Marx generator, a MOSFET driving circuit and an electromagnetic probe. The direct current power supply respectively supplies power to the Marx generator and the MOSFET driving circuit, the signal generator provides pulse signals for the MOSFET driving circuit to control the on and off of the MOSFET, and then transient electromagnetic pulses with pulse width and frequency being set values are generated on the electromagnetic probe. The device can generate voltage pulse signals with adjustable amplitude and variable pulse width (200-2000 ns) at two ends of the electromagnetic probe at the load end, so as to generate transient electromagnetic pulses with different intensities, wherein the pulse width and the frequency of the transient electromagnetic pulses are set values, on the electromagnetic probe. The electromagnetic pulse generator has the advantages of simple design principle, low manufacturing cost and good circuit stability.
Description
Technical Field
The invention relates to the field of electromagnetic pulse fault injection, in particular to a nanosecond electromagnetic pulse generator for electromagnetic fault injection.
Background
With the continuous shrinking feature sizes of CMOS processes, the electromagnetic compatibility of integrated circuits is receiving more and more attention and research. Electromagnetic fault injection (EMFI) refers to that a chip is attacked by a local strong magnetic field generated by an electromagnetic probe, so that transient induced voltage and current are generated inside the chip, and faults are introduced to the attacked chip. Electromagnetic fault injection is used as a novel attack method, can attack the local part of a chip and acquire confidential information by utilizing a password analysis technology, and is widely applied. To develop effective protection measures, the failure mechanism of electromagnetic pulse failure injection to an integrated circuit chip needs to be studied. Therefore, it is necessary to develop a parameter-adjustable electromagnetic pulse generator.
The Marx generator is widely used in the field of electromagnetic fault injection because it can conveniently generate high voltage through cascading. Although the electromagnetic pulse generator developed at present has higher pulse amplitude and shorter rising time, the control circuit is complex, the experimental device is huge, and the service life and the frequency are greatly limited due to the use of a spark gap and the like as a switch, and the amplitude and the pulse width are difficult to adjust. Because the MOSFET switch device has the advantages of compactness, high repetition frequency, portability, low cost, high efficiency and the like, the MOSFET switch device can be combined with the MOSFET drive circuit to generate a pulse signal with large current change rate, and the nanosecond electromagnetic pulse generator with simple circuit structure, low cost and adjustable electromagnetic pulse output frequency and intensity can be developed.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides a nanosecond electromagnetic pulse generator for electromagnetic fault injection, which adopts a MOSFET as a switching device of a Marx generator, guides the selection of circuit components and the design of a PCB based on simulation analysis of Hspice software to the circuit, and realizes the controllable adjustment of the output frequency and the intensity of electromagnetic pulse.
The invention aims at realizing the following technical scheme:
a nanosecond electromagnetic pulse generator for electromagnetic fault injection comprises a direct current power supply, a signal generator, a Marx generator, a MOSFET driving circuit and an electromagnetic probe,
the direct current power supply is respectively connected with the MOSFET driving circuit and the Marx generator and used for providing power for the MOSFET driving circuit and the Marx generator;
the MOSFET driving circuit is internally provided with an MOSFET driving chip, a transient voltage suppression diode (TVS), a protection resistor (R1) and a grid driving resistor (Rg); the input end of the MOSFET driving chip is connected with the output end of the signal generator, the output end of the MOSFET driving chip is connected with the grid driving resistor (Rg), the transient voltage suppression diode (TVS) is connected with the grid driving resistor (Rg) in series, and the protection resistor (R1) is connected with the transient voltage suppression diode (TVS) in parallel;
the Marx generator comprises a charging isolation Resistor (RC) and one to four stages of adjustable Marx circuits, wherein one end of the charging isolation Resistor (RC) is connected with the output end of the direct current power supply and is used for isolating high voltage of the Marx circuits from the direct current power supply and limiting charging current; the other end of the charging isolation Resistor (RC) is connected with the positive electrode of a diode of a first stage circuit of the Marx circuit through a wire, and each stage of Marx circuit consists of a MOSFET switch, an energy storage capacitor and a diode; the cathode of the diode in each stage of the Marx circuit is connected with the parallel point of the MOSFET switch and the energy storage capacitor through a lead; the Marx circuit changes the circuit structure by placing jumper caps at the connection positions of all levels on the PCB; the grid source electrode of the MOSFET switch is respectively connected with a transient voltage suppression diode (TVS) of the MOSFET drive circuit in parallel so as to avoid the damage of devices caused by the overvoltage of the grid source electrode of the MOSFET switch; when the MOSFET switch is in an off state, the diode is conducted to form a charging current loop of the energy storage capacitor, and the energy storage capacitor is charged in parallel to a set voltage value of the direct current power supply; when the MOSFET switch is in a conducting state, the diode is reversely cut off to form a discharging current loop of the energy storage capacitor, the energy storage capacitor which is fully filled to a preset voltage value discharges the electromagnetic probe in a serial mode, and the conducting time of the MOSFET switch is controlled to enable the two ends of the electromagnetic probe to obtain high-voltage nanosecond pulse square waves with corresponding pulse width, so that transient electromagnetic pulses with the pulse width and the frequency being set values are generated on the electromagnetic probe; when the MOSFET switch is turned back off, the storage capacitor is charged again.
Further, the electromagnetic probe comprises three parameters of coil turns, copper wire diameter and ferrite core diameter; and different types of electromagnetic probes are obtained through setting the three parameters and are used for generating electromagnetic pulse signals with different intensities.
Further, the intensity of the electromagnetic pulse generated by the electromagnetic probe is proportional to the rate of change of the current on the electromagnetic probe.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
1) The invention adopts MOSFET as the switching device of Marx generator, so that the electromagnetic pulse generator has high repetition frequency and long service life.
2) In the driving part of the MOSFET switch, the MOSFET switch is rapidly charged and discharged through the MOSFET driving chip and the grid driving resistor Rg with low resistance value, so that the switching speed of the MOSFET is improved, and voltage pulses with rising edges and falling edges reaching the nanosecond level can be generated at the two ends of the electromagnetic probe, so that transient electromagnetic pulses with pulse width and frequency being set values are generated on the electromagnetic probe.
3) The invention adopts different types of electromagnetic probes, thereby being convenient for generating electromagnetic pulse signals with different electromagnetic intensities.
4) The invention guides the selection of circuit components and the design of the PCB based on the simulation analysis of Hsps software, and provides reference for the design of an electromagnetic pulse generating circuit; the circuit has high working stability, realizes the random adjustment of electromagnetic pulse amplitude, pulse width and frequency, can generate the induction voltage of 2.9V at the maximum to a single-turn receiving coil with the diameter of 1.5mm at the distance of 0.5mm, and lays a foundation for electromagnetic fault injection experiments.
Drawings
Fig. 1 is a functional block diagram of an electromagnetic pulse generator.
Fig. 2 is a schematic diagram of the structure of a MOSFET driving circuit.
Fig. 3 is a schematic diagram of a Marx generator circuit with adjustable stage number.
Fig. 4 (a) and 4 (b) are pulse waveforms outputted from both ends of the electromagnetic probe, respectively.
Detailed Description
The present invention will be described in further detail with reference to specific examples.
As shown in fig. 1, there is a schematic block diagram of an electromagnetic pulse generator comprising: the system comprises a direct current power supply, a signal generator, a Marx generator, a MOSFET driving circuit and an electromagnetic probe. The direct current power supply respectively supplies power to the Marx generator and the MOSFET driving circuit, the signal generator provides pulse signals for the MOSFET driving circuit and controls the on and off of the MOSFET switch, so that transient electromagnetic pulses with pulse width and frequency being set values are generated on the electromagnetic probe.
As shown in fig. 2, a schematic circuit design structure of the MOSFET driving circuit is shown. A driving resistor Rg is connected in series between the driving chip and the MOSFET grid electrode, and the driving resistor Rg is properly valued so as to reduce the oscillation amplitude of the driving signal; and simultaneously, a transient voltage suppression diode TVS and a resistor R1 are connected in parallel with the grid and the source of the MOSFET so as to further limit the grid and the source overvoltage of the MOSFET.
As shown in fig. 3, is a schematic circuit diagram of the Marx generator. The invention designs an n-stage Marx generator circuit with adjustable stages, wherein each stage of circuit consists of a diode, a MOSFET switch and an energy storage capacitor. In the embodiment, n is 1, in the figure, D1-D2 n are diodes, C1-Cn are energy storage capacitors, M1-Mn are MOSFET switches, VDD is a direct current power supply, RC is a current limiting resistor, and magnetic_microprobe is an electromagnetic probe at a load end.
The selected MOSFET driving chip is IXDN609PI, the selected transient voltage suppression diode is SMBJ16CA, the selected diode is a fast recovery diode DSEI60-06A, and the selected MOSFET switch is IXFB100N50Q3.
The method comprises the following specific steps:
(1) Selecting electromagnetic probes for attack
The invention selects a cylindrical ferrite core to enhance the magnetic conductivity of the probe, designs 15 specific small electromagnetic probes by using copper wires with the diameter of 0.1mm, wherein the diameters of the probes are respectively 0.7mm, 1mm and 1.2mm, and the turns of coils are respectively 1, 3, 5, 7 and 9, so as to generate electromagnetic pulses with different attack areas and different electromagnetic intensities; the diameter of the electromagnetic probe selected in the embodiment is 1.2mm, and the number of turns of the coil is 7;
(2) Supplying power to the driving chip and charging the energy storage capacitor
As shown in fig. 2, the dc power supply provides a power supply voltage of 18V for the MOSFET driving chip, and the trigger pulse signal of the signal generator is used as an input signal of the MOSFET driving chip, and after passing through the driving chip, the amplitude of the output pulse signal is 18V, and the maximum rising and falling time of the pulse can reach 20ns, so as to rapidly drive the MOSFET to be turned on and turned off;
as shown in fig. 3, in the charging stage, MOSFET switches M1 to Mn are turned off, diodes D1 to D2n are turned on to form a charging current path, and the dc power supply charges parallel capacitors C1 to Cn to a dc power supply voltage VDD through a current limiting protection resistor RC and a diode pair;
(3) Discharging the capacitor in series during the MOSFET turn-on phase
As shown in FIG. 3, in the discharging stage, M1-Mn is conducted, D1-D2 n is reversely cut off, capacitors C1-Cn are discharged in a series mode, n-level equivalent series capacitor voltage is rapidly applied to two ends of a load electromagnetic probe, so that the voltage n times of VDD is obtained, and transient electromagnetic pulses are generated on the electromagnetic probe;
(4) Generating transient electromagnetic pulses on an electromagnetic probe
The waveforms of the voltage pulses generated at the two ends of the electromagnetic probe in this embodiment are shown in fig. 4 (a) and 4 (b); during testing, a primary Marx generator circuit is selected, the output voltage VDD of a direct current power supply is 0-50V, the current-limiting resistance RC is 1KΩ, the grid resistance Rg is 1 Ω, and the load resistance RL connected with the electromagnetic probe in series is 20 Ω; FIG. 4 (a) shows the output of voltage pulse signals with pulse widths of 200ns, 1us and 2us at the load end according to the pulse width setting of the signal generator; fig. 4 (b) shows voltage pulse waveforms of the load end in the case where the dc power supply VDD outputs voltages of 24V, 38V and 50V, respectively;
the invention adopts a single-turn receiving coil with the diameter of 1.5mm, and connects a testing coil with an oscilloscope through a BNC coaxial cable so as to test the magnitude of induced electromotive force generated on the receiving coil by different electromagnetic probes; experiments show that when the three-stage Marx generator circuit is used and the electromagnetic probe is fixedly arranged at the position 0.5mm above the receiving coil, the induction voltage measured on the receiving coil is up to 2.9V, so that the chip to be attacked can be failed.
The invention is not limited to the embodiments described above. The above description of specific embodiments is intended to describe and illustrate the technical aspects of the present invention, and is intended to be illustrative only and not limiting. Numerous specific modifications can be made by those skilled in the art without departing from the spirit of the invention and scope of the claims, which are within the scope of the invention.
Claims (1)
1. A nanosecond electromagnetic pulse generator for electromagnetic fault injection is characterized by comprising a direct-current power supply, a signal generator, a Marx generator, a MOSFET driving circuit and an electromagnetic probe,
the direct current power supply is respectively connected with the MOSFET driving circuit and the Marx generator and used for providing power for the MOSFET driving circuit and the Marx generator;
the MOSFET driving circuit is internally provided with an MOSFET driving chip, a transient voltage suppression diode (TVS), a protection resistor (R1) and a grid driving resistor (Rg); the input end of the MOSFET driving chip is connected with the output end of the signal generator, the output end of the MOSFET driving chip is connected with the grid driving resistor (Rg), the transient voltage suppression diode (TVS) is connected with the grid driving resistor (Rg) in series, and the protection resistor (R1) is connected with the transient voltage suppression diode (TVS) in parallel;
the Marx generator comprises a charging isolation Resistor (RC) and one to four stages of adjustable Marx circuits, wherein one end of the charging isolation Resistor (RC) is connected with the output end of the direct current power supply and is used for isolating high voltage of the Marx circuits from the direct current power supply and limiting charging current; the other end of the charging isolation Resistor (RC) is connected with the positive electrode of a diode of a first stage circuit of the Marx circuit through a wire, and each stage of Marx circuit consists of a MOSFET switch, an energy storage capacitor and a diode; the cathode of the diode in each stage of the Marx circuit is connected with the parallel point of the MOSFET switch and the energy storage capacitor through a lead; the Marx circuit changes the circuit structure by placing jumper caps at the connection positions of all levels on the PCB; the grid source electrode of the MOSFET switch is respectively connected with a transient voltage suppression diode (TVS) of the MOSFET driving circuit in parallel so as to avoid damage to devices caused by overvoltage of the grid source electrode of the MOSFET switch, and the electromagnetic probe comprises three parameters, namely a coil turns, a copper wire diameter and a ferrite core diameter; and different types of electromagnetic probes are obtained through setting the three parameters and are used for generating electromagnetic pulse signals with different intensities, and the electromagnetic pulse intensity generated by the electromagnetic probes is in direct proportion to the current change rate on the electromagnetic probes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711041567.3A CN107818218B (en) | 2017-10-31 | 2017-10-31 | Nanosecond electromagnetic pulse generator for electromagnetic fault injection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711041567.3A CN107818218B (en) | 2017-10-31 | 2017-10-31 | Nanosecond electromagnetic pulse generator for electromagnetic fault injection |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107818218A CN107818218A (en) | 2018-03-20 |
| CN107818218B true CN107818218B (en) | 2023-11-21 |
Family
ID=61604406
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711041567.3A Active CN107818218B (en) | 2017-10-31 | 2017-10-31 | Nanosecond electromagnetic pulse generator for electromagnetic fault injection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107818218B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109307829A (en) * | 2018-11-23 | 2019-02-05 | 西安交通大学 | With the detection device and its detection method of transient earth voltage shelf depreciation on site |
| CN109660030A (en) * | 2018-11-23 | 2019-04-19 | 西安揽智俱应智能科技有限公司 | With the emitter and its launching technique of transient earth voltage shelf depreciation on site |
| DE102018221518A1 (en) * | 2018-12-12 | 2020-06-18 | Siemens Healthcare Gmbh | High-voltage generator for providing a high-voltage pulse |
| CN109596953B (en) * | 2018-12-20 | 2021-06-22 | 国网北京市电力公司 | Electromagnetic wave emission device and partial discharge test instrument |
| CN109900988A (en) * | 2019-03-14 | 2019-06-18 | 合肥格威特电气技术有限公司 | A kind of two fingers number test gimulator of electromagnetic pulse electric current access |
| CN112994658A (en) * | 2021-03-14 | 2021-06-18 | 国网内蒙古东部电力有限公司呼伦贝尔供电公司 | Marx generator-based pulse source with adjustable waveform |
| CN113381740A (en) * | 2021-03-19 | 2021-09-10 | 国网内蒙古东部电力有限公司呼伦贝尔供电公司 | Compact hybrid isolation Marx pulse generator for plasma discharge |
| CN114094988B (en) * | 2022-01-18 | 2022-09-09 | 杭州维纳安可医疗科技有限责任公司 | Pulse generating circuit, equipment and method with pulse detection function |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103684360A (en) * | 2013-12-24 | 2014-03-26 | 国家电网公司 | Implementing method of high-voltage square-wave generator |
| CN203617979U (en) * | 2013-12-24 | 2014-05-28 | 国家电网公司 | High-voltage square-wave generator |
| WO2014193254A1 (en) * | 2013-05-28 | 2014-12-04 | Instituto Superior Tecnico | Modular generator for bipolar or unipolar pulses with correction of voltage decay integrated in power semiconductor modules |
| CN205105184U (en) * | 2015-11-24 | 2016-03-23 | 国家电网公司 | All solid state nanosecond pulser MOSFET drive circuit |
| CN105634441A (en) * | 2016-04-01 | 2016-06-01 | 中国人民解放军军械工程学院 | High-efficiency and double-exponential electromagnetic pulse generation device |
| CN107124163A (en) * | 2017-05-04 | 2017-09-01 | 重庆大学 | A kind of composite mode solid state pulse source |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100820171B1 (en) * | 2006-11-02 | 2008-04-07 | 한국전기연구원 | Pulse power generator using semiconductor switch |
-
2017
- 2017-10-31 CN CN201711041567.3A patent/CN107818218B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014193254A1 (en) * | 2013-05-28 | 2014-12-04 | Instituto Superior Tecnico | Modular generator for bipolar or unipolar pulses with correction of voltage decay integrated in power semiconductor modules |
| CN103684360A (en) * | 2013-12-24 | 2014-03-26 | 国家电网公司 | Implementing method of high-voltage square-wave generator |
| CN203617979U (en) * | 2013-12-24 | 2014-05-28 | 国家电网公司 | High-voltage square-wave generator |
| CN205105184U (en) * | 2015-11-24 | 2016-03-23 | 国家电网公司 | All solid state nanosecond pulser MOSFET drive circuit |
| CN105634441A (en) * | 2016-04-01 | 2016-06-01 | 中国人民解放军军械工程学院 | High-efficiency and double-exponential electromagnetic pulse generation device |
| CN107124163A (en) * | 2017-05-04 | 2017-09-01 | 重庆大学 | A kind of composite mode solid state pulse source |
Non-Patent Citations (1)
| Title |
|---|
| 细胞外钙调素对转基因烟草悬浮细胞rbcS-GUS基因表达的促进作用;马力耕, 周君莉, 张素巧, 刘强, 孙大业;科学通报(第19期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107818218A (en) | 2018-03-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107818218B (en) | Nanosecond electromagnetic pulse generator for electromagnetic fault injection | |
| Jiang et al. | Pulsed power generation by solid-state LTD | |
| US10631395B2 (en) | Inductively coupled pulsed RF voltage multiplier | |
| Li et al. | Theoretical analysis and experimental study on an avalanche transistor-based Marx generator | |
| Zorngiebel et al. | Modular 50-kV IGBT switch for pulsed-power applications | |
| Rao et al. | Nanosecond pulse generator based on cascaded avalanche transistors and Marx circuits | |
| CN112165313A (en) | Avalanche transistor-based high-amplitude high-repetition-frequency fast pulse generation circuit | |
| Sun et al. | All-solid-state bipolar pulsed generator based on linear transformer driver and push–pull circuit | |
| Wang et al. | Novel repetitive square wave voltage generator used for the insulation evaluation of rotating machines driven by power electronics | |
| Yan et al. | Miniature solid-state switched spiral generator for the cost effective, programmable triggering of large scale pulsed power accelerators | |
| Gusev et al. | A thyristor switch with a subnanosecond switching time | |
| Qiu et al. | Stray parameters in a novel solid state pulsed power modulator | |
| KR101054244B1 (en) | Trigger device and driving method for impulse generator | |
| CN207397276U (en) | A kind of nanosecond electromagnetic pulse generator for electromagnetism direct fault location | |
| CN208849692U (en) | A kind of compact high-voltage switch gear component | |
| Pemen et al. | Synchronous pulse systems | |
| Richter-Sand et al. | Marx-stacked IGBT modulators for high voltage, high power applications | |
| CN202696455U (en) | Field effect transistor drive circuit | |
| Mota et al. | Generation of dc high voltage pulse for hipot testing using pfn based marx generator | |
| Huiskamp et al. | 15-Stage compact Marx generator using 2N5551 avalanche transistors | |
| CN104764911A (en) | Ringing wave test signal generator based on electronic switches | |
| Sun et al. | Bipolar solid-state LTD based on push-pull circuit | |
| CN102931821A (en) | Field effect tube driving circuit | |
| KR101269514B1 (en) | Short pulse current generator for high current | |
| CN215728590U (en) | Reverse surge tester for high-power high-frequency high-voltage silicon stack |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |