Broadband electrostatic transient pulse protection module

Abstract

The invention discloses a broadband electrostatic transient pulse protection module, and relates to the technical field of electrostatic protection devices. The input end of the protection circuit is divided into two paths after passing through a first terminal load Tem1, the first path is grounded through a gas discharge tube X9, the second path is connected with one end of an inductor L7, the other end of the inductor L7 is divided into three paths, the first path is connected with one end of an impedance conversion network V1, the second path is grounded through a transient suppression diode X2, and the other end of the inductor L7 is connected with the other end of the impedance conversion network V1. The third path is grounded through a transient voltage suppressor X3 and a transient voltage suppressor X4 in sequence; the other end of the impedance conversion network V1 is divided into three paths, the first path is connected with one end of the impedance conversion network V2, the second path is grounded through a transient suppression diode X5, and the third path is grounded through a transient suppression diode X6; the other end of the impedance conversion network V2 is divided into three paths, the first path is connected with one end of an inductor L6, and the second path is grounded through a transient suppression diode X7. The protection circuit can effectively improve the electrostatic pulse protection performance and has good transmission characteristics.

Description

Technical Field

[0001] This invention relates to the field of electrostatic discharge protection devices, and in particular to a broadband electrostatic transient pulse protection module. Background Technology

[0002] Electrostatic discharge (ESD), a nanosecond-level transient interference, can have peak discharge currents reaching hundreds of amperes. The discharge process is typically accompanied by a wide-bandwidth, high-intensity electromagnetic field, which can enter the aircraft's interior through radio frequency antennas, power lines, signal lines, or through holes and gaps, causing damage to the aircraft's internal electronic equipment. Therefore, designing ESD protection for the ports of aircraft electronic equipment is crucial for ensuring aircraft safety. Pulse protection devices are commonly used for transient pulse protection, and research on this topic is quite extensive both domestically and internationally. Among them, transient voltage suppressors (TVS) are widely used for transient pulse protection due to their excellent response speed. They can clamp transient pulses within nanoseconds or even sub-nanoseconds, effectively protecting electronic components. However, due to the material and structural characteristics of TVS, their current withstand capability is relatively poor, and using TVS alone cannot meet protection requirements. Other pulse protection devices with stronger current withstand capabilities, such as gas discharge tubes, varistors, and semiconductor discharge tubes, have insufficient response speed. They cannot respond promptly to fast-rising nanosecond-level ESD electromagnetic pulses, leading to significant peak leakage and causing interference or even damage to electronic equipment. In summary, a single type of pulse protection device cannot simultaneously meet the requirements of high current and fast response electrostatic pulse protection. Therefore, it is necessary to combine the characteristics of various protection devices to develop a composite electrostatic pulse protection module for aircraft. This will reduce the interference or damage of electrostatic pulses to the electronic systems of aircraft and is of great significance for improving the electrostatic safety of aircraft. Summary of the Invention

[0003] The technical problem to be solved by the present invention is how to provide a broadband electrostatic transient pulse protection module with good electrostatic pulse protection performance and transmission characteristics.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a broadband electrostatic transient pulse protection module, wherein the input terminal of the protection circuit is divided into two paths after passing through a first terminal load Tem1. The first path is grounded through a gas discharge tube X9, and the second path is connected to one end of an inductor L7. The other end of the inductor L7 is divided into three paths: the first path is connected to one end of an impedance transformation network V1, the second path is grounded through a transient suppression diode X2, and the third path is grounded sequentially through transient suppression diodes X3 and X4. The other end of the impedance transformation network V1 is divided into three paths: the first path is connected to one end of an impedance transformation network V2, the second path is grounded through a transient suppression diode X5, and the third path is grounded through a transient suppression diode X6. The other end of the impedance transformation network V2 is divided into three paths: the first path is connected to one end of an inductor L6, the second path is grounded through a transient suppression diode X7, and the third path is grounded through a transient suppression diode X8. The other end of the inductor L6 is grounded after passing through a second terminal load Tem2.

[0005] This invention also discloses a broadband electrostatic transient pulse protection module. The input terminal of the protection circuit is connected to one end of microstrip line TL16 via a first terminal load Tem1, microstrip line TL17, and capacitor C2. The other end of microstrip line TL16 is divided into three paths: the first path is grounded via inductor L1 and varistor CV2; the second path is grounded via inductor L2 and varistor CV1, then via capacitor C3 and microstrip line TL15; and the third path is connected to one end of microstrip line TL11. The other end of microstrip line TL11 is divided into three paths: the first path is grounded via transient suppression diode X2; the second path is connected to one end of microstrip line TL3; and the third path is grounded via transient suppression diode X1 and microstrip line TL12, then via capacitor C1 and microstrip line TL13. The other end of microstrip line TL3 is grounded via capacitor C4, microstrip line TL2, and second terminal load Tem2.

[0006] This invention also discloses a broadband electrostatic transient pulse protection module test system, comprising: an insertion loss test module, a TLP test module, an HBM test module, and a throughput test module.

[0007] The insertion loss test module is used to test the transmission characteristics of a broadband electrostatic transient pulse protection module.

[0008] The TLP test module is used to perform TLP testing on a broadband electrostatic transient pulse protection module.

[0009] The HBM test module is used to perform HBM waveform testing on a broadband electrostatic transient pulse protection module.

[0010] The flow rate test module is used to perform flow rate testing on a broadband electrostatic transient pulse protection module.

[0011] A further technical solution is that the insertion loss test module includes a vector network analyzer, which is used to test the transmission characteristics of a broadband electrostatic transient pulse protection module.

[0012] A further technical solution is as follows: The TLP test module includes a charging voltage source, a transmission line, and a single-pole double-throw switch S1. The charging voltage source is connected to the transmission line TL1 and the transmission line TL2 respectively through the switch S1. The charging voltage source is used to provide rated energy to charge the transmission line TL1 and generate a narrow square wave. When the switch S1 is closed, a broadband electrostatic transient pulse protection module is connected to the transmission line. The narrow square wave acts on the protection structure of the broadband electrostatic transient pulse protection module. The measured values ​​are obtained through an oscilloscope, and then the voltage and current values ​​at both ends of the broadband electrostatic transient pulse protection module are obtained through calculation.

[0013] The beneficial effects of adopting the above technical solution are as follows: The protection circuit described in this application uses TVS diodes as the core protection device. Through gradual optimization of peak leakage and insertion loss, a protection circuit with relatively good performance is obtained. According to different operating frequencies, two electrostatic pulse protection circuits applicable to operating frequencies of 1MHz-500MHz and 0.5GHz-2GHz are designed respectively. According to the simulation results, the response time of the protection module applied to the operating frequency of 1MHz-500MHz is about 1.07ns. When the input terminal is a 4000kV square wave voltage, the peak leakage is 15.8V, the clamping voltage is 12V, and the maximum insertion loss in the frequency band is 0.07dB. The protection module, applied to the 0.5-2GHz frequency range, employs a combination of MOV and TVS due to its high operating frequency. The circuit utilizes microstrip line matching. When the injected signal amplitude is 4kV, the protection circuit reaches a peak voltage of 220V at 1.05ns, subsequently exhibiting a decaying trend, ultimately clamping the voltage to less than 37V. The response time is 1.05ns, and the maximum insertion loss within the frequency band is 0.2dB. Overall, both EPS protection modules demonstrate good EPS protection performance and transmission characteristics, effectively improving EPS protection performance while exhibiting excellent transmission characteristics. Attached Figure Description

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0015] Figure 1 This is a schematic diagram of a broadband electrostatic transient pulse protection module (operating frequency 1MHz-500MHz) according to Embodiment 1 of the present invention.

[0016] Figures 2a-2dThe transient response diagram of fast-edge square wave injection in the protection circuit described in Embodiment 1 of the present invention (input voltages are 1kV, 2kV, 3kV and 4kV respectively).

[0017] Figure 3 This is a schematic diagram of a broadband electrostatic transient pulse protection module (operating frequency 1GHz-2GHz) according to Embodiment 2 of the present invention.

[0018] Figure 4a This is a simulation diagram of the insertion loss of the protection circuit described in Embodiment 2 of the present invention;

[0019] Figure 4b This is a simulation diagram of the standing wave ratio (VSWR) of the protection circuit described in Embodiment 2 of the present invention;

[0020] Figure 5 This is an insertion loss test diagram in the test system described in the embodiment of the present invention;

[0021] Figure 6 This is a graph showing the insertion loss test results in the test system described in this embodiment of the invention;

[0022] Figure 7 This is a diagram showing the composition of the TLP testing module in the testing system described in this embodiment of the invention;

[0023] Figure 8 This is a waveform diagram of the ES660 electrostatic pulse current during HBM testing of the testing system described in this embodiment of the invention;

[0024] Figure 9a This refers to the transient response (full waveform of output voltage) of the protection module under different levels of electrostatic pulse in the test system described in the embodiment of the present invention.

[0025] Figure 9b This refers to the transient response (output voltage front-end waveform) of the protection module under different levels of electrostatic pulse in the test system described in the embodiments of the present invention.

[0026] Figure 10 This is a graph showing the relationship between peak current and energy under electrostatic pulse in the testing system described in this embodiment of the invention.

[0027] Figure 11 This is a diagram showing the leakage current test results of the protection module in the test system described in this embodiment of the invention;

[0028] Figure 12 This is a waveform diagram of the current output of the protection module in the test system described in the embodiment of the present invention when it is close to failure. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0031] Example 1:

[0032] Overall, such as Figure 1 This invention discloses a wideband electrostatic transient pulse protection module, applicable to operating frequencies of 1MHz-500MHz, wherein the protection circuit includes:

[0033] The input terminal of the protection circuit is split into two paths after passing through the first terminal load Tem1. The first path is grounded through the gas discharge tube X9, and the second path is connected to one end of the inductor L7. The other end of the inductor L7 is split into three paths: the first path is connected to one end of the impedance transformation network V1, the second path is grounded through the transient suppression diode X2, and the third path is grounded sequentially through transient suppression diodes X3 and X4. The other end of the impedance transformation network V1 is split into three paths: the first path is connected to one end of the impedance transformation network V2, the second path is grounded through the transient suppression diode X5, and the third path is grounded through the transient suppression diode X6. The other end of the impedance transformation network V2 is split into three paths: the first path is connected to one end of the inductor L6, the second path is grounded through the transient suppression diode X7, and the third path is grounded through the transient suppression diode X8. The other end of the inductor L6 is grounded after passing through the second terminal load Tem2. Further, the impedance transformation network V1 includes inductors L4 and C7 connected in parallel; the impedance transformation network V2 includes inductors L5 and C8 connected in parallel.

[0034] like Figure 1As shown, the first stage of the protection circuit uses parallel gas discharge tubes. The gas discharge tubes are low-capacitance devices with a maximum current capacity of 2kA and a junction capacitance of 0.5nF to improve the overall response time of the protection module and reduce insertion loss. The subsequent TVS diodes form a three-stage protection structure. The final stage, X7 and X8, are 110-02EL TVS diodes with a fast response speed, featuring a low capacitance of 0.4pF, a low series resistance of 0.6Ω, and a parasitic inductance of 0.2nF. The intermediate stage devices X5 and X6 are 131-02EL TVS diodes, while the preceding stage devices X2, X3, and X4 are 119-02EL TVS diodes. The series resistances of these two TVS diodes are 0.67Ω and 0.8Ω, respectively. The series resistance of the three TVS diodes decreases progressively, achieving a layered reduction in clamping voltage.

[0035] Square wave pulse transient response simulation:

[0036] Transient response simulation of the protection circuit was performed using ADS. The input signal was a 0-4kV square wave pulse with a rise and fall time of 1ns and a pulse width of 100ns. Square wave pulse simulation can accurately evaluate the protection circuit's response to transient pulse impacts. The circuit output voltage waveform is shown below. Figures 2a-2d As shown.

[0037] Simulation results show that the protection circuit's output response characteristics differ when different levels of square wave voltage are injected: spike leakage and clamping voltage increase with increasing square wave voltage. When the input voltage is 4000kV, significant spike leakage (15.8V) and clamping voltage (12V) are observed. In summary, the protection module effectively controls these spike leaks at a low voltage level, providing reliable protection for subsequent parts of the circuit. Furthermore, the module exhibits an extremely fast response speed of 0.34ns. Preliminary simulation data demonstrate that the protection module provides effective protection against fast-rising-edge square wave pulses.

[0038] Example 2

[0039] like Figure 3As shown, this embodiment of the invention discloses a wideband electrostatic transient pulse protection module, applied to a working frequency of 1GHz-2GHz. The protection circuit includes: the input terminal of the protection circuit is connected to one end of microstrip line TL16 via a first terminating load Tem1, microstrip line TL17, and capacitor C2 in sequence; the other end of microstrip line TL16 is divided into three paths: the first path is grounded via inductor L1 and varistor CV2 in sequence; the second path is grounded via inductor L2 and varistor CV1 in sequence, then via capacitor C3 and microstrip line TL15; the third path is connected to one end of microstrip line TL11; the other end of microstrip line TL11 is divided into three paths: the first path is grounded via transient suppression diode X2; the second path is connected to one end of microstrip line TL3; the third path is grounded via transient suppression diode X1 and microstrip line TL12 in sequence, then via capacitor C1 and microstrip line TL13; the other end of microstrip line TL3 is grounded via capacitor C4, microstrip line TL2, and second terminating load Tem2 in sequence.

[0040] The protection circuit adopts a multi-stage cascaded protection method. The spacing between the strip lines of the two-stage devices is one-quarter wavelength of the center frequency. The length and width of the series microstrip line are calculated based on the center frequency. The value of the parallel inductance is adjusted according to the selection of different devices to achieve the optimal result.

[0041] S-parameter simulation:

[0042] Under matched conditions, the transmission performance of the simulation circuit is simulated, and the S-parameters of the protection module are as follows: Figures 4a-4b As shown in the figure. Through simulation analysis, it can be seen that within the frequency range of 1GHz to 2GHz, the insertion loss of this module remains below 0.2dB, while its VSWR remains below 1.085, indicating that the protection circuit has relatively good transmission characteristics.

[0043] Example 3

[0044] This invention also discloses a broadband electrostatic transient pulse protection module test system, comprising: an insertion loss test module, a TLP test module, an HBM test module, and a throughput test module.

[0045] The insertion loss test module is used to test the transmission characteristics of a broadband electrostatic transient pulse protection module.

[0046] The TLP test module is used to perform TLP testing on a broadband electrostatic transient pulse protection module.

[0047] The HBM test module is used to perform HBM waveform testing on a broadband electrostatic transient pulse protection module.

[0048] The flow rate test module is used to perform flow rate testing on a broadband electrostatic transient pulse protection module.

[0049] Insertion loss test:

[0050] The transmission characteristics of the electrostatic discharge protection module were tested using a vector network analyzer. The connection method is as follows: Figure 5 As shown, according to Figure 5 The connection method was tested and set up, with a starting frequency of 1MHz and a cutoff frequency of 500MHz. Insertion loss tests were performed on the protection device, and the test results are as follows. Figure 6 As shown.

[0051] Depend on Figure 6 It can be seen that the maximum insertion loss of the protection module is 0.51dB and the minimum is 0.12dB in the range of 1MHz to 500MHz. The test results show that the introduction of this module has little impact on the normal operating signal in the frequency band, which meets the design requirements.

[0052] Protection module TLP test:

[0053] The TLP test module is composed as follows: Figure 7 As shown, the device includes a charging voltage source, transmission lines, and a single-pole double-throw switch S1. The charging voltage source is connected to transmission lines TL1 and TL2 via switch S1. The charging voltage source provides rated energy to charge transmission line TL1 and generate a narrow square wave. When switch S1 is closed, a broadband electrostatic transient pulse protection module is connected to the transmission line. The narrow square wave acts on the protection structure of the broadband electrostatic transient pulse protection module. The measured values ​​are obtained through an oscilloscope, and then the voltage and current values ​​at both ends of the broadband electrostatic transient pulse protection module are obtained through calculation.

[0054] The TLP pulse width is adjusted by changing the length of TL1, and the TLP pulse voltage is adjusted by changing the voltage V0. In actual testing, the TLP pulse amplitude is gradually increased by incrementing the high voltage power supply until the DUT fails or the maximum measurable voltage is reached.

[0055] HBM test:

[0056] Electrostatic discharge (ESD) testing was conducted using the ES660 series component ESD testing system. Its HBM waveform test specifications meet ANSI / ESDA / JEDECJS-001, MIL-STD-883E, AECQ100-002, and GJB548C-2021 Method 3015.1. The system's output ESD level can reach up to 20kV. Its output HBM pulse waveform and main parameters are as follows: Figure 8 As shown.

[0057] The step voltage was set to gradually increase from 1kV to 20kV. The transient response waveform of the protection module was recorded, including electrostatic pulse tests at 5kV, 10kV, 15kV, and 20kV. The test results are as follows: Figures 9a-9b As shown. From Figures 9a-9b It can be seen that there is a noticeable oscillation waveform at the front end of the output voltage of the protection module, but the overall trend meets the change law of clamping after the peak. The maximum peak value of the 20kV level pulse output is 109.08V, and the voltage then drops to 7.55V. This process takes about 20ns.

[0058] Protection module throughput test:

[0059] The protection circuit consists of a parallel structure of a primary GDT and multiple TVS diodes. The multiple TVS diodes at the back end determine the overall response speed and clamping efficiency of the device. The primary GDT accelerates conduction through the voltage rise effect of the TVS diodes, discharging large currents. Analyzing the entire operation, the back-end TVS devices are the most vulnerable to damage, and their current-carrying capacity is relatively weak among surge protection devices. Therefore, the current-carrying capacity of the protection module mainly depends on the current-carrying capacity of the TVS diodes. Currently, the current-carrying capacity of TVS diodes is defined and measured using an 8 / 20μs lightning pulse. For example, the Infineon series diodes used in this module clearly specify in their datasheets the electrostatic withstand voltage rating measured according to IEC61000-4-2 (ESD) and the current-carrying capacity value measured using an 8 / 20μs surge pulse according to IEC61000-4-5. However, in reality, the pulse width of a single electrostatic pulse is much lower than the pulse width of a single lightning surge specified in the standard, and the energy released by an electrostatic pulse is much lower than the energy released by a lightning pulse. Therefore, the current carrying capacity of a device measured according to this standard cannot truly reflect the device's ability to protect against electrostatic discharge.

[0060] To address this issue, this application employs an energy equivalence approach. Multiple sets of pulse energy and current values ​​obtained during electrostatic discharge (ESD) testing of the protective device are fitted with formulas and curves. The device undergoes lightning surge current testing with a standard 8 / 20μs waveform and progressively increasing voltage values. Based on the test results, the current value corresponding to the device's failure threshold and the energy at that point are determined. The obtained energy value is then substituted into the previously fitted formulas and curves to obtain the equivalent current value corresponding to that point from the ESD pulse. The ESD pulse test current and energy results are as follows: Figure 10 As shown:

[0061] The existing data was fitted using a multinomial fitting scheme to ensure fitting accuracy. The fitting result is shown in the formula:

[0062] ;

[0063] Surge current testing was performed on the protection devices, gradually increasing the surge level until device failure. Failure determination was based on the same method as the TLP test: device failure was considered complete when the leakage current showed an order-of-magnitude increase. A critical point before the leakage current underwent an order-of-magnitude change was selected. The test results are as follows: Figure 11 As shown, the corresponding current output waveform at this time is as follows: Figure 12 As shown.

[0064] It can be seen that when the protective device is nearing failure, the current is approximately 11.5A, and the energy it withstands is approximately 2.1mJ. In the measurement data of the protective module under electrostatic pulse (ESP), the maximum current value is approximately 10A, corresponding to an energy of 13.37μJ. Using a fitting formula to perform an equivalent conversion between ESP and surge pulse energy, substituting the energy value of 2.1mJ, we can obtain a corresponding ESP current value of approximately 220A. This indicates that the protective module can withstand a peak current of 220A under ESP.

[0065] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A broadband electrostatic transient pulse protection module, characterized in that: The input of the protection circuit is divided into two paths after passing through the first terminal load Tem1. The first path is grounded through the gas discharge tube X9, and the second path is connected to one end of the inductor L7. The other end of the inductor L7 is divided into three paths: the first path is connected to one end of the impedance transformation network V1, the second path is grounded through the transient suppression diode X2, and the third path is grounded sequentially through transient suppression diodes X3 and X4. The other end of the impedance transformation network V1 is divided into three paths: the first path is connected to one end of the impedance transformation network V2, the second path is grounded through the transient suppression diode X5, and the third path is grounded through the transient suppression diode X6. The other end of the impedance transformation network V2 is divided into three paths: the first path is connected to one end of the inductor L6, the second path is grounded through the transient suppression diode X7, and the third path is grounded through the transient suppression diode X8. The other end of the inductor L6 is grounded after passing through the second terminal load Tem2.

2. The broadband electrostatic transient pulse protection module as described in claim 1, characterized in that: The impedance transformation network V1 includes an inductor L4 and a capacitor C7 connected in parallel.

3. The broadband electrostatic transient pulse protection module as described in claim 1, characterized in that: The impedance transformation network V2 includes an inductor L5 and a capacitor C8 connected in parallel.

4. A broadband electrostatic transient pulse protection module, characterized in that: The input terminal of the protection circuit is connected to one end of microstrip line TL16 via the first terminal load Tem1, microstrip line TL17, and capacitor C2. The other end of microstrip line TL16 is divided into three paths: the first path is grounded via inductor L1 and varistor CV2; the second path is grounded via inductor L2 and varistor CV1, then via capacitor C3 and microstrip line TL15; and the third path is connected to one end of microstrip line TL11. The other end of microstrip line TL11 is divided into three paths: the first path is grounded via transient suppression diode X2; the second path is connected to one end of microstrip line TL3; and the third path is grounded via transient suppression diode X1 and microstrip line TL12, then via capacitor C1 and microstrip line TL13. The other end of microstrip line TL3 is grounded via capacitor C4, microstrip line TL2, and the second terminal load Tem2.

5. A broadband electrostatic transient pulse protection module testing system, characterized in that... include: Insertion loss test module, TLP test module, HBM test module, and throughput test module. The insertion loss test module is used to test the transmission characteristics of a broadband electrostatic transient pulse protection module. The TLP test module is used to perform TLP testing on a broadband electrostatic transient pulse protection module. The HBM test module is used to perform HBM waveform testing on a broadband electrostatic transient pulse protection module. The flow rate test module is used to perform flow rate testing on a broadband electrostatic transient pulse protection module.

6. The broadband electrostatic transient pulse protection module test system as described in claim 5, characterized in that: The insertion loss test module includes a vector network analyzer, which is used to test the transmission characteristics of a broadband electrostatic transient pulse protection module.

7. The broadband electrostatic transient pulse protection module test system as described in claim 5, characterized in that: The TLP test module includes a charging voltage source, a transmission line, and a single-pole double-throw switch S1. The charging voltage source is connected to transmission lines TL1 and TL2 respectively via switch S1. The charging voltage source provides rated energy to charge transmission line TL1 and generate a narrow square wave. When switch S1 is closed, a broadband electrostatic transient pulse protection module is connected to the transmission line. The narrow square wave acts on the protection structure of the broadband electrostatic transient pulse protection module. The measured values ​​are obtained through an oscilloscope, and then the voltage and current values ​​at both ends of the broadband electrostatic transient pulse protection module are obtained through calculation.

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