EOS peak voltage detection device

Abstract

The utility model discloses an EOS peak voltage detection device, and belongs to the technical field of circuits. The detection signal access module accesses a plurality of detection contact signals to the signal attenuation and protection module, the signal attenuation and protection module attenuates the voltage of the detection signals by a fixed multiple, and the peak voltage detection module captures the peak voltage of positive and negative pulses and converts the peak voltage into analog DC voltage. Detection results of the multi-path peak voltage detection module are converged into the voltage acquisition module, the voltage acquisition module carries out sampling conversion on the detection results, the EOS peak voltages of a plurality of detection contacts are detected at the same time, the data display and storage module displays the detection results in real time, and the position of a risk source is positioned and reported according to the detection results. According to the EOS peak voltage detection device, the number of detection contacts is not limited by the number of oscilloscope channels, a plurality of monitored objects can be systematically detected online, detection results can be reported in real time, and an EOS risk source can be rapidly identified.

Description

Technical Field

[0001] The utility model relates to the technical field of communication electronics, in particular to an EOS peak voltage detection device. Background Art

[0002] In today's society, electronic devices have become an indispensable part of our daily lives. With the rapid development of the semiconductor industry, the integration degree of chips is getting higher and higher, and the product size is getting smaller and smaller. In the semiconductor industry, product function failure events caused by EOS (Electrical Over Stress) occur frequently. EOS mainly comes from the leakage of the reflow soldering chain during the SMT (Surface Mount Technology) processing, the leakage of the electric screwdriver bit used during the assembly process, the leakage of the panel cutting tooling or platform, or the leakage of the track of the movement controlled by the servo; and the peak pulse voltage generated during the processes such as live contact during the PCBA (Printed Circuit Board Assembly) FT (Functional Test) and hot plugging during the test with the assembled power supply.

[0003] As Figure 1 shown, EOS voltage signals are mostly positive and negative single pulse voltages or high-voltage power frequency interference superimposed pulse voltages. Such rapidly rising pulse voltages have a relatively high voltage amplitude and a certain current driving ability. Their voltage range is 0V to dozens of volts, and the frequency is 50 to hundreds of kHz. If they come into contact with the pins of an integrated circuit chip, they will break down the chip and cause the chip to short-circuit and fail. In the case of a large variety of equipment on the processing workshop line and many product assembly processes, if batch EOS breakdown failures occur in the products, it will bring huge economic losses to the manufacturer.

[0004] Therefore, a method for quickly and low-costly detecting EOS for the entire processing flow nodes, related equipment and processes, identifying risk sources, and quickly judging risk positions is needed. The traditional detection method is to use an oscilloscope to monitor the contacts to be detected. The number of detected contacts is limited by the number of oscilloscope channels, and it is impossible to systematically detect multiple monitoring objects, which brings inconvenience to quickly identifying EOS risk sources. In addition, oscilloscope detection belongs to an off-line detection method and cannot report the detection results in real time. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is: aiming at the defects such as limited number of channels when using detection devices such as oscilloscopes for EOS detection in the prior art and inability to quickly identify EOS risk sources, an EOS peak voltage detection device is provided.

[0006] To achieve the above object, the utility model provides an EOS peak voltage detection device, which includes a plurality of detection signal access modules, a plurality of signal attenuation and protection modules, a plurality of peak voltage detection modules, a voltage acquisition module, and a data display and storage module, wherein:

[0007] The detection signal access modules, the signal attenuation and protection modules, and the peak voltage detection modules are in one-to-one correspondence, and each path corresponds to a detection channel;

[0008] The input end of the detection signal access module is connected to the contact to be detected, and the output end is connected to the input end of the signal attenuation and protection module;

[0009] The signal attenuation and protection module attenuates the voltage of the input detection signal by a fixed multiple; the output end of the signal attenuation and protection module is connected to the input end of the peak voltage detection module;

[0010] The peak voltage detection module captures and holds the peak voltages of positive and negative pulses from the attenuated detection signal and converts them into analog DC voltages; the output end of the peak voltage detection module is connected to the input end of the voltage acquisition module;

[0011] The voltage acquisition module samples and converts the input analog DC voltage into a peak voltage value; the output end of the voltage acquisition module is connected to the input end of the data display and storage module;

[0012] The data display and storage module is used to display and record the peak voltage values of each detection channel in real time, and locate and report the position of the risk source according to the peak voltage values.

[0013] Preferably, the device further includes a power supply module and a power conversion module;

[0014] The power supply module provides power for the device; the output end of the power supply module is connected to the input end of the power conversion module;

[0015] The power conversion module converts the output voltage of the power supply module into the working voltages of the peak voltage detection module and the voltage acquisition module; the output end of the power conversion module is connected to the power input end of the peak voltage detection module and the power input end of the voltage acquisition module.

[0016] Preferably, the signal attenuation and protection module includes a first resistor, a second resistor, a third resistor, and a bidirectional TVS tube; one end of the first resistor is connected to the output end of the detection signal input module, and the other end is respectively connected to the second resistor and the third resistor; the other end of the second resistor is respectively connected to the bidirectional TVS tube and the input end of the peak voltage detection module; the other end of the third resistor is grounded; the other end of the bidirectional TVS tube is grounded; the resistance values of the first resistor and the second resistor are equal.

[0017] Preferably, the peak voltage detection module includes a positive peak voltage detection circuit and a negative peak voltage detection circuit.

[0018] Preferably, the positive peak voltage detection circuit includes a first operational amplifier, a second operational amplifier, a first diode, a second diode, a third diode, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, and a second capacitor;

[0019] The non-inverting input terminal of the first operational amplifier is connected to the output end of the signal attenuation and protection module, and the inverting input terminal of the first operational amplifier is connected to the inverting input terminal of the second operational amplifier through the fourth resistor; the inverting input terminal of the first operational amplifier is also connected to the anode of the first diode, the cathode of the first diode is connected to the output end of the first operational amplifier, and the first capacitor is connected in parallel with the first diode;

[0020] The output end of the first operational amplifier is also connected to the anode of the second diode, the cathode of the second diode is connected to the anode of the third diode, and the cathode of the third diode is respectively connected to the sixth resistor and the non-inverting input terminal of the second operational amplifier; the other end of the sixth resistor is grounded; the cathode of the second diode is also connected to the output end of the second operational amplifier through the fifth resistor; the second capacitor is connected in parallel with the sixth resistor; the inverting input terminal of the second operational amplifier is connected to the output end of the second operational amplifier;

[0021] The positive and negative power supply pins of the first operational amplifier and the second operational amplifier are connected to the output end of the power conversion module; the output end of the second operational amplifier is connected to the input end of the voltage acquisition module.

[0022] Preferably, the negative peak voltage detection circuit includes a third operational amplifier, a fourth operational amplifier, a fifth operational amplifier, a fourth diode, a fifth diode, a sixth diode, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a third capacitor, and a fourth capacitor;

[0023] The non-inverting input terminal of the third operational amplifier is connected to the output terminal of the signal attenuation and protection module, and the inverting input terminal is connected to the inverting input terminal of the fourth operational amplifier through the seventh resistor; the inverting input terminal of the third operational amplifier is also connected to the cathode of the fourth diode, the anode of the fourth diode is connected to the output terminal of the third operational amplifier, and the third capacitor is connected in parallel with the fourth diode;

[0024] The output terminal of the third operational amplifier is also connected to the cathode of the fifth diode, the anode of the fifth diode is connected to the cathode of the sixth diode, and the anode of the sixth diode is respectively connected to the ninth resistor and the non-inverting input terminal of the fourth operational amplifier; the other end of the ninth resistor is grounded; the anode of the fifth diode is also connected to the output terminal of the fourth operational amplifier through the eighth resistor; the fourth capacitor is connected in parallel with the ninth resistor; the inverting input terminal of the fourth operational amplifier is connected to the output terminal of the fourth operational amplifier;

[0025] The output terminal of the fourth operational amplifier is connected to the inverting input terminal of the fifth operational amplifier through the tenth resistor; the non-inverting input terminal of the fifth operational amplifier is grounded through the twelfth resistor; the inverting input terminal of the fifth operational amplifier is connected to the output terminal of the fifth operational amplifier through the eleventh resistor;

[0026] The positive and negative power supply pins of the third operational amplifier, the fourth operational amplifier, and the fifth operational amplifier are connected to the output terminal of the power conversion module; the output terminal of the fifth operational amplifier is connected to the input terminal of the voltage acquisition module.

[0027] Preferably, the power supply module is the USB interface power supply of a computer.

[0028] Preferably, the voltage acquisition module is a single-chip microcomputer.

[0029] Preferably, the data display and storage module uses the SSCOM serial port debugging assistant running on a computer to display and record the EOS peak voltage of each detection channel.

[0030] Preferably, the detection signal access module includes two BNC connectors and a copper cable connecting the two BNC connectors, one of the BNC connectors is connected to the input terminal of the signal attenuation and protection module, and the other BNC connector is connected to the detected contact and the reference ground.

[0031] The utility model has the following beneficial effects: The EOS peak voltage detection device provided by the utility model includes a plurality of detection signal access modules, a plurality of signal attenuation and protection modules, a plurality of peak voltage detection modules, a voltage acquisition module, and a data display and storage module. The detection signal access modules, the signal attenuation and protection modules, and the peak voltage detection modules are in one-to-one correspondence, and each path corresponds to a detection channel. The detection signal access module accesses the detection contact signals on the external device to the signal attenuation and protection module. After the signal attenuation and protection module attenuates the voltage of the detection signal by a fixed multiple, it is input to the peak voltage detection module for peak detection. The peak voltage detection module captures the peak voltages of positive and negative pulses and converts them into analog DC voltages. The detection results of multiple peak voltage detection modules are merged into the same voltage acquisition module. The voltage acquisition module samples and converts the detection results, converting the analog DC voltage into a peak voltage value, realizing the detection of the EOS peak voltages of multiple detection contacts simultaneously. The data display and storage module displays the detection results in real time and locates and reports the position of the risk source according to the detection results. The number of detection contacts of the EOS peak voltage detection device of the utility model is not limited by the number of oscilloscope channels. In an environment such as a workshop, by connecting the possible risk contacts to this device one by one, it is possible to systematically perform on-line EOS peak voltage detection on multiple monitoring objects, report the detection results in real time, and quickly identify EOS risk sources. Compared with the off-line detection method using an oscilloscope, it is more intelligent and more responsive. Description of the Drawings

[0032] The drawings described herein are used to provide a further understanding of the utility model and constitute a part of the utility model. The schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an improper limitation of the utility model. In the drawings:

[0033] Figure 1 It is a schematic diagram of the EOS voltage waveform.

[0034] Figure 2 It is a block diagram of the EOS peak voltage detection device provided by the embodiment of the utility model.

[0035] Figure 3 It is a schematic diagram of the power supply relationship provided by the embodiment of the utility model.

[0036] Figure 4 It is a schematic diagram of the structure of the EOS peak voltage detection device provided by the embodiment of the utility model.

[0037] Figure 5 It is a circuit schematic diagram of the signal attenuation and protection module and the peak voltage detection module provided by the embodiment of the utility model.

[0038] Figure 6Schematic diagram of the EOS peak voltage detection result provided by the embodiment of the present utility model. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0040] The embodiments of the present utility model will be further described in detail below with reference to the accompanying drawings of the specification. It should be understood that the embodiments described herein are only used to illustrate and explain the present utility model and are not used to limit the present utility model.

[0041] The EOS peak voltage detection device provided by the present utility model can be used as an EOS risk source equipment monitoring system in the workshop to obtain the peak voltage magnitude of the equipment or the leakage point at any time; it can also be used as an EOS risk source detection system to identify whether there is an EOS risk during the assembly and testing processes; it can also be applied to the instrument and meter system as a detection instrument to measure the leakage voltage magnitude of the equipment and judge whether there is a leakage risk.

[0042] As Figure 2 shown, the embodiment of the present utility model provides an EOS peak voltage detection device, which includes a plurality of detection signal access modules, a plurality of signal attenuation and protection modules, a plurality of peak voltage detection modules, a voltage acquisition module, and a data display and storage module.

[0043] The detection signal access modules, the signal attenuation and protection modules, and the peak voltage detection modules correspond one by one, and each path corresponds to a detection channel. In practical applications, multiple contacts on one device or multiple devices can be monitored simultaneously, and each contact is connected to a detection signal access module as the input signal of a detection channel.

[0044] The input end of the detection signal access module is connected to the contact to be detected, and the output end is connected to the input end of the signal attenuation and protection module.

[0045] The present utility model does not impose special restrictions on the specific implementation manner of the detection signal access module. In some embodiments of the present utility model, the detection signal access module includes two BNC connectors and a copper cable connecting the two BNC connectors. One of the BNC connectors is connected to the input end of the signal attenuation and protection module, and the other BNC connector is connected to the detected contact and the reference ground. The reference ground is usually an exposed metal contact on the device, a moving metal platform or chain contact, a pogo pin on the FCT test device, etc. The BNC (Bayonet Neill-Concelman) connector is a common coaxial cable connector. The characteristic of the BNC connector lies in its fast connection and disconnection mechanism. The structure of the BNC connector includes a central conductor for signal transmission, an outer shielding layer for grounding and preventing electromagnetic interference, an insulating layer for isolating the central conductor and the shielding layer, and an external bayonet connection mechanism, which enables it to be firmly connected to the adapted socket and ensure good electrical contact and shielding performance. By selecting the BNC connector and coaxial cable, the shielding effect is good and the transmission loss at a certain distance is small. Therefore, using the BNC connector can realize the access and detection of the EOS peak signals of multiple devices distributed discretely in a large workshop. In other embodiments of the present utility model, ordinary wires are used as the detection contact signal access medium. Each BNC connector is connected to a detection contact, corresponding to a detection channel.

[0046] The signal attenuation and protection module attenuates the voltage of the input detection signal by a fixed multiple; the output end of the signal attenuation and protection module is connected to the input end of the peak voltage detection module.

[0047] The signal attenuation and protection module attenuates the voltage of the input detection signal by a fixed multiple without affecting the frequency of the detection signal.

[0048] The peak voltage detection module captures and holds the peak voltages of the positive and negative pulses from the attenuated detection signal and converts them into analog DC voltages; the output end of the peak voltage detection module is connected to the input end of the voltage acquisition module.

[0049] Since the EOS signal may appear as a positive pulse or a negative pulse, the peak voltage detection module includes a positive peak voltage detection circuit and a negative peak voltage detection circuit.

[0050] The voltage acquisition module samples and converts the input analog DC voltage into a peak voltage value; the output end of the voltage acquisition module is connected to the input end of the data display and storage module. The voltage acquisition module samples and converts the DC voltage input by the peak voltage detection module, converting the analog DC voltage into a peak voltage value.

[0051] In some embodiments of the present utility model, the voltage acquisition module is a single-chip microcomputer. Sampling high-speed and fast-rising-edge pulse signals requires relatively high sampling speed and number of bits for the single-chip microcomputer, and the sampled data also needs to be temporarily stored and processed. Voltage acquisition devices with too low performance cannot ensure sampling the peak voltage of the pulse signal. It may sample at a smooth position or a rising-edge position, resulting in inaccurate sampled voltage values. The single-chip microcomputer adopted in the embodiments of the present utility model includes an MCU chip with 12-bit AD sampling function to achieve voltage value sampling with lower error. The AD interface of the single-chip microcomputer sets a sampling interval of 100 ms, and the reference voltage selects 3.3 V voltage. The output end of the peak voltage detection module is connected to the GPIO port of the single-chip microcomputer. Each EOS peak voltage signal corresponds to a positive peak voltage detection result and a negative peak voltage detection result of the peak voltage detection module. The positive peak voltage detection result and the negative peak voltage detection result are respectively connected to a GPIO port on the single-chip microcomputer. Therefore, two GPIO ports correspond to an EOS signal detection channel. Connecting the EOS peak voltages of multiple detection channels to the same single-chip microcomputer can simultaneously detect and collect multi-channel EOS signals. Therefore, in environments such as workshops, connecting possible risk contacts to this device one by one can systematically perform on-line EOS peak voltage detection on multiple monitoring objects. Compared with using an oscilloscope to detect EOS signals, the number of detection channels in this solution is not limited by the hardware channels of the oscilloscope. By modifying the program of the single-chip microcomputer MCU, voltage signal acquisition of more detection channels can be achieved, and the scalability of the channel number is stronger. It can systematically perform on-line EOS signal detection on multiple monitoring objects, thereby achieving rapid identification of EOS risk sources. Compared with the off-line detection method of the oscilloscope, it is more intelligent and more responsive.

[0052] The data display and storage module is used to display and record in real time the peak voltage values of each detection channel and locate and report the position of the risk source according to the peak voltage values.

[0053] The voltage value displayed by the data display and storage module is the voltage value after compensating for the attenuation of the signal attenuation and protection module.

[0054] In some embodiments of the present utility model, the data display and storage module uses the SSCOM serial port debugging assistant running on a computer to display and record the EOS peak voltages of each detection channel. The single-chip microcomputer is connected to the computer through a USB cable. The single-chip microcomputer is connected to a USB-to-serial port chip, and the EOS peak voltage data of each collected detection channel is sent to the computer through the serial port. The SSCOM serial port debugging assistant running on the computer displays in real time the positive and negative EOS peak voltage values of each detection channel. In addition, the computer can also burn the program package to the single-chip microcomputer through the USB cable.

[0055] Such asFigure 6 As shown, the SSCOM serial port debugging assistant displays the EOS peak voltage values of multiple serial port channels virtualized by the USB-to-serial chip. Among them, every two serial port channels correspond to one detection channel. For example, CH0 corresponds to the positive peak voltage of one detection channel, CH1 corresponds to the negative peak voltage of the same detection channel, and CH2 and CH3 respectively correspond to the positive and negative peak voltages of another detection channel. Figure 6 In this case, there are a total of 10 serial port channels, corresponding to the positive and negative peak voltage values of 5 detection channels. In practical applications, different numbers of detection channels can be connected to the EOS peak voltage detection device provided by the embodiment of the present invention according to needs.

[0056] The peak voltage displayed by the SSCOM serial port debugging assistant is the voltage value after compensating for the attenuation of the signal attenuation and protection module. For example, the signal attenuation and protection module attenuates the input EOS voltage signal by a fixed multiple of 5 times. If the EOS voltage peak sampled by the voltage acquisition module is U, the EOS voltage peak displayed by the SSCOM serial port debugging assistant is 5U.

[0057] In the SSCOM serial port debugging assistant, it is possible to set to save the data received by the serial port to a file to achieve the purpose of real-time recording of the EOS peak voltage of each detection channel. In addition, a data processing program can be run synchronously on the computer to process the data saved by the SSCOM serial port debugging assistant, store the detected EOS peak voltage data in the database, and locate and report the position of the risk source according to the correspondence between the pre-entered serial port channel and the detection contact. The present invention does not limit the specific reporting method. For example, the risk source information can be reported to the relevant responsible personnel in the workshop through various methods such as phone, WeChat, DingTalk, and text messages. Further, a series of thresholds of different sizes can be set, and different levels of alarms can be given according to the range where the EOS peak voltage is located.

[0058] In other embodiments of the present invention, a specially developed dedicated data processing software can be used to replace the SSCOM serial port debugging assistant to achieve a more personalized display effect, and at the same time integrate the functions of serial port data processing, locating and reporting risk sources.

[0059] Compared with the solution of offline EOS peak voltage detection using an oscilloscope, the solution of the present invention can record and display the detected EOS peak voltage in real time, quickly locate and report the EOS risk source based on this, process the EOS peak voltage more timely, and effectively avoid batch EOS breakdown failures of products.

[0060] Such as Figure 3As shown, the EOS peak voltage detection device further includes a power supply module and a power conversion module; the power supply module provides power for the EOS peak voltage detection device; the output end of the power supply module is connected to the input end of the power conversion module; the power conversion module converts the output voltage of the power supply module into the working voltages of the peak voltage detection module and the voltage acquisition module; the output end of the power conversion module is connected to the power input end of the peak voltage detection module and the power input end of the voltage acquisition module.

[0061] The present utility model has no special limitation on the power supply module. For example Figure 4 As shown, in some embodiments of the present utility model, the power supply module is the USB interface power supply of a computer, and the voltage value is 5V. In other embodiments of the present utility model, other dedicated power supplies can also be used for the power supply module.

[0062] The peak voltage detection module usually includes a comparator. The comparator needs to be connected to positive and negative reference voltages as the working voltage, and the voltage acquisition module also has requirements for the working voltage. The working voltage values of the comparator and the voltage acquisition module are different. Therefore, it is necessary to convert the voltage provided by the power supply module into the working voltage of the comparator in the peak voltage detection module and the working voltage of the acquisition module through the power conversion module. For example Figure 4 - Figure 5 As shown, to achieve the detection of input voltages of ±100V, the input EOS voltage is attenuated by a fixed multiple of 5 times. The maximum input voltage at the non-inverting terminal of the operational amplifier is 22V. The positive and negative reference voltages required by each comparator in the peak voltage detection module are 22V and -22V respectively, and the working voltage of the voltage acquisition module is +3.3V. In the embodiment of the present utility model, the +5V power supply of the USB interface on the computer is used as the power supply module. The power conversion module directly converts +5V into +3.3V voltage through an LDO voltage chip to supply the 3.3V working voltage of the single-chip microcomputer system and the reference voltage of the AD acquisition voltage; the power conversion module boosts and buck-boosts the voltage to ±22V for power supply, as the working voltage of the operational amplifier in the peak detection module, so that both positive and negative voltages can be detected.

[0063] The voltage range of the EOS voltage is 0V to several tens of V. Ordinary single-chip microcomputer sampling devices cannot directly sample such high-voltage pulses. Therefore, it is necessary to attenuate the voltage signal obtained by the detection signal access module so that the voltage value of the signal drops to the range that can be processed by ordinary sampling devices. The present utility model has no special limitation on the specific form of the signal attenuation circuit.

[0064] For example Figure 4 - Figure 5As shown in the figure, to achieve the detection of the input voltage of ±100V, the input EOS voltage is attenuated by a fixed multiple of 5 times. In practical applications, the attenuation multiple needs to be set according to the range of the input voltage, and then the corresponding attenuation circuit is designed. The specific implementation of the signal attenuation circuit of the present utility model is not particularly limited.

[0065] As Figure 5 shown, in some embodiments of the present utility model, a T-shaped resistor attenuation network is used to attenuate the signal to be detected. The signal attenuation and protection module includes a first resistor R1, a second resistor R2, a third resistor R3, and a bidirectional TVS tube TVS1; one end of the first resistor R1 is connected to the output end of the detection signal input module, and the other end is respectively connected to the second resistor R2 and the third resistor R3; the other end of the second resistor R2 is respectively connected to the bidirectional TVS tube TVS1 and the input end of the peak voltage detection module; the other end of the third resistor R3 is grounded; the other end of the bidirectional TVS tube TVS1 is grounded; the resistance values of the first resistor R1 and the second resistor R2 are equal.

[0066] In practical applications, the resistance values of the first resistor R1, the second resistor R2, and the third resistor R3 are selected according to the set attenuation multiple. In some embodiments of the present utility model, the Figure 5 shown T-shaped resistor attenuation network is adopted. In order to achieve an attenuation with a fixed multiple of 5 times, the resistance values of the first resistor R1 and the second resistor R2 are taken as 10 kΩ, and the resistance value of the third resistor R3 is taken as 2.5 kΩ.

[0067] As Figure 5 shown, a bidirectional TVS tube TVS1 is added after the attenuated voltage to protect the op-amp pin of the subsequent peak detection circuit. To achieve the detection of the input voltage of ±100V, the front-stage fixed attenuation multiple is 5 times. In the peak detection circuit, the input voltage at the non-inverting terminal of the op-amp is at most 22V, and a Schottky diode with a VBR voltage of 20V is selected for the diode. After the fixed attenuation multiple, if the amplitude of the input voltage is greater than the operating voltage of the Schottky diode, the bidirectional TVS tube TVS1 will clamp the input voltage to protect the input pin of the subsequent peak voltage detection device and the sampling pin of the single-chip microcomputer system.

[0068] In other embodiments of the present utility model, a π-shaped resistor attenuation network is used to attenuate the signal to be detected. When the π-shaped resistor attenuation network processes high-frequency signals, the voltage attenuation multiple is not as stable as that of the T-shaped resistor attenuation network. In practical applications, a suitable attenuation network can be selected according to the test situation.

[0069] The present utility model has no special limitation on the specific implementation of the peak detection circuit.

[0070] As Figure 5As shown in the figure, in some embodiments of the present utility model, the positive peak voltage detection circuit includes a first operational amplifier U1A, a second operational amplifier U1B, a first diode D1, a second diode D2, a third diode D3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, and a second capacitor C2;

[0071] The non-inverting terminal of the first operational amplifier U1A is connected to the output terminal of the signal attenuation and protection module, and the inverting terminal of the first operational amplifier U1A is connected to the inverting terminal of the second operational amplifier U1B through the fourth resistor R4; the inverting terminal of the first operational amplifier U1A is also connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the output terminal of the first operational amplifier U1A, and the first capacitor C1 is connected in parallel with the first diode D1 to prevent self-excited oscillation during the conduction process and stabilize the first operational amplifier U1A;

[0072] The output terminal of the first operational amplifier U1A is also connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the anode of the third diode D3, and the cathode of the third diode D3 is respectively connected to the sixth resistor R6 and the non-inverting terminal of the second operational amplifier U1B; the other end of the sixth resistor R6 is grounded; the cathode of the second diode D2 is also connected to the output terminal of the second operational amplifier U1B through the fifth resistor R5; the second capacitor C2 is connected in parallel with the sixth resistor R6; the inverting terminal of the second operational amplifier U1B is connected to the output terminal of the second operational amplifier U1B. The fifth resistor R5 is connected to the output terminal of the second operational amplifier to form a feedback, thereby eliminating the influence of the leakage current of the third diode D3. During the process of capacitor charging and maintaining voltage, the two ends of the third diode D3 have the same potential, reducing the influence of the leakage current of the third diode D3 on the voltage change of the second capacitor C2, enabling the second capacitor C2 to better store the peak voltage and thus improving the detection accuracy.

[0073] The positive and negative power supply pins of the first operational amplifier U1A and the second operational amplifier U1B are connected to the output terminal of the power conversion module; the output terminal of the second operational amplifier U1B is connected to the input terminal of the voltage acquisition module.

[0074] Figure 5 In the embodiment, the first operational amplifier U1A and the second operational amplifier U1B are powered by a ±22V dual power supply, and the output terminal of the second operational amplifier U1B is connected to the GPIO pin of the single-chip microcomputer through the P2 terminal.

[0075] For high-frequency pulse waveforms, the capacitance value of the second capacitor C2 should be appropriately small so that it can quickly respond to changes and detect the maximum level. To maintain the capacitor peak for a longer time, the capacitance value of the second capacitor C2 cannot be too small. In actual implementation, when the frequency is less than 1 MHz, the capacitance value of the second capacitor C3 can be selected as 1 μF.

[0076] At the same time, to improve the response speed of the detection module to high-frequency rapidly rising pulse voltage signals, an operational amplifier with high bandwidth and high slew rate needs to be selected. In some embodiments of the present invention, the first operational amplifier U1A and the second operational amplifier U1B select NE5532. To reduce the diode conduction voltage drop, increase the conversion rate, and the current flowing through the second capacitor C2, the first diode D1, the second diode D2, and the third diode D3 all select Schottky diodes to adapt to the detection of high-frequency fast pulse signals, thereby reducing the detection error of high-frequency signals. When the first capacitor C1 passes through a higher frequency, a 1 pF capacitor is selected. The fourth resistor R4 and the fifth resistor R5 select 10 kΩ resistors to feedback voltage signals and form a feedback loop. The sixth resistor R6 and the second capacitor C2 form a discharge loop, and the sixth resistor R6 selects a 1 MΩ resistor to make the second capacitor C2 discharge slowly.

[0077] The working principle of the positive peak voltage detection circuit is as follows:

[0078] The initial voltage of the inverting terminal of the first operational amplifier U1A is 0. The EOS voltage signal is connected to the signal attenuation and protection circuit from the BNC connector P1, and after being attenuated by a fixed multiple, it is input to the non-inverting terminal of the first operational amplifier U1A. If the EOS voltage signal is a positive pulse, the voltage of the non-inverting terminal of the first operational amplifier U1A is greater than the voltage of the inverting terminal. The initial state of the second capacitor C2 is defaulted to a low voltage. The feedback loop of the first operational amplifier U1A is virtually short-circuited, and the second diode D2 and the third diode conduct, quickly charging the second capacitor C2. The second operational amplifier U1B follows the voltage after the second capacitor C2 is charged. When the input voltage increases, the second capacitor C2 will maintain this state until the maximum voltage peak is saved, and the maximum peak voltage is converted into a DC voltage and input to the subsequent voltage acquisition module.

[0079] When the voltage at the non-inverting terminal of the first operational amplifier U1A decreases, that is, when the other peak voltages within the same finger pulse decrease or the pulse voltage disappears and the next pulse voltage has not yet appeared, the input voltage of the second diode D2 decreases, causing the second diode D2 to be reverse-biased. Since the first capacitor C1 still retains the previous voltage peak, the output voltage of the first operational amplifier U1A decreases, and the feedback loop through the fourth resistor R4 is disconnected. Then, the output terminal of the first operational amplifier U1A attempts to reach the negative rail voltage. The first diode D1 and the inverting terminal of the first operational amplifier U1A form a feedback loop, and the first diode D1 is forward-biased, providing local feedback to the first operational amplifier U1A. The first operational amplifier U1A clamps the positive voltage of the first diode D1 at a voltage drop 0.3V lower than the input signal at the non-inverting terminal of the first operational amplifier U1A. This state remains until the input voltage at the non-inverting terminal of the first operational amplifier U1A exceeds the voltage held on the first capacitor C1. The clamping of the positive voltage of the first diode D1 shortens the conversion time for the second capacitor C2 to return from the holding state to the tracking state, enabling the second capacitor C2 to charge more quickly in response.

[0080] The negative peak voltage detection circuit includes a third operational amplifier U2A, a fourth operational amplifier U2B, a fifth operational amplifier U3B, a fourth diode D4, a fifth diode D5, a sixth diode D6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a third capacitor C3, and a fourth capacitor C4;

[0081] The non-inverting terminal of the third operational amplifier U2A is connected to the output terminal of the signal attenuation and protection module, and the inverting terminal is connected to the inverting terminal of the fourth operational amplifier U2B through the seventh resistor R7; the inverting terminal of the third operational amplifier U2A is also connected to the cathode of the fourth diode D4, the anode of the fourth diode D4 is connected to the output terminal of the third operational amplifier U2A, and the third capacitor C3 is connected in parallel with the fourth diode D4;

[0082] The output terminal of the third operational amplifier U2A is also connected to the cathode of the fifth diode D5, the anode of the fifth diode D5 is connected to the cathode of the sixth diode D6, and the anode of the sixth diode D6 is connected to both the ninth resistor R9 and the non-inverting terminal of the fourth operational amplifier U2B; the other end of the ninth resistor R9 is grounded; the anode of the fifth diode D5 is also connected to the output terminal of the fourth operational amplifier U2B through the eighth resistor R8; the fourth capacitor C4 is connected in parallel with the ninth resistor R9; the inverting terminal of the fourth operational amplifier U2B is connected to the output terminal of the fourth operational amplifier U2B;

[0083] The output terminal of the fourth operational amplifier U2B is connected to the inverting terminal of the fifth operational amplifier U3B through the tenth resistor R10; the non-inverting terminal of the fifth operational amplifier U3B is grounded through the twelfth resistor R12; the inverting terminal of the fifth operational amplifier U3B is connected to the output terminal of the fifth operational amplifier U3B through the eleventh resistor R11;

[0084] The positive and negative power supply pins of the third operational amplifier U2A, the fourth operational amplifier U2B, and the fifth operational amplifier U3B are connected to the output terminal of the power conversion module; the output terminal of the fifth operational amplifier U3B is connected to the input terminal of the voltage acquisition module.

[0085] Figure 5 In the embodiment, the third operational amplifier U2A, the fourth operational amplifier U2B, and the fifth operational amplifier U3B are powered by a ±22V dual power supply, and the output terminal of the fifth operational amplifier U3B is connected to the GPIO pin of the single-chip microcomputer through the P2 terminal.

[0086] The negative peak voltage detection circuit is used to detect negative voltage pulse signals. The orientations of the anode and cathode of the diode are opposite to those of the positive peak voltage detection circuit. Similar to the positive peak detection circuit, the fourth diode D4, the fifth diode D5, and the sixth diode D6 are all selected as Schottky diodes. The method for selecting the capacitance value of the fourth capacitor C4 is the same as that of the second capacitor C3, and the method for selecting the resistance values of the seventh resistor, the eighth resistor, and the ninth resistor is also the same as that of the resistors at the corresponding positions in the positive peak voltage detection circuit. The tenth resistor, the eleventh resistor, and the twelfth resistor are selected as resistors with the same resistance value to form a 1:1 inverting proportional amplifier circuit, which converts the negative pulse voltage peak output by the fourth operational amplifier U2B into a positive voltage inverting pulse voltage peak.

[0087] The working principle of the negative peak voltage detection circuit is similar to that of the positive peak voltage detection circuit, and the present invention will not elaborate on this.

[0088] In other embodiments of the present invention, a step-by-step comparison circuit is used to continuously compare the input voltage value with the threshold set by the system, so as to detect the EOS peak voltage. Compared with Figure 5 the shown method, this method requires more reference voltages and comparators to be generated, the circuit is more complex, and it cannot provide accurate measurement results.

[0089] The utility model has the following beneficial effects: The EOS peak voltage detection device provided by the utility model includes multiple detection signal access modules, multiple signal attenuation and protection modules, multiple peak voltage detection modules, a voltage acquisition module, and a data display and storage module. The detection signal access modules, signal attenuation and protection modules, and peak voltage detection modules correspond one by one, and each path corresponds to a detection channel. The detection signal access module accesses the multiple detection contact signals on the external device to the signal attenuation and protection module. After the signal attenuation and protection module attenuates the voltage of the detection signal by a fixed multiple, it is input to the peak voltage detection module for peak detection. The peak voltage detection module captures the peak voltages of positive and negative pulses and converts them into analog DC voltages. The detection results of multiple peak voltage detection modules are merged into the same voltage acquisition module. The voltage acquisition module samples and converts the detection results, converting the analog DC voltage into peak voltage values, realizing the detection of the EOS peak voltages of multiple detection contacts simultaneously. The data display and storage module displays the detection results in real time and locates and reports the position of the risk source according to the detection results. The number of detection contacts of the EOS peak voltage detection device of the utility model is not limited by the number of oscilloscope channels. In an environment such as a workshop, by connecting the possible risk contacts to this device one by one, it is possible to systematically perform on-line EOS peak voltage detection on multiple monitoring objects, report the detection results in real time, and quickly identify EOS risk sources. Compared with the method of off-line detection by an oscilloscope, it is more intelligent and more responsive.

[0090] The above is only the specific implementation manner of the utility model, and the scope of the utility model cannot be limited by this. Equal changes made by ordinary technicians in the technical field according to this creation, as well as changes well-known to technicians in the field, should still fall within the scope covered by the utility model.

Claims

1. An EOS peak voltage detection device, characterized in that: The device includes multiple detection signal access modules, multiple signal attenuation and protection modules, multiple peak voltage detection modules, a voltage acquisition module, and a data display and storage module, wherein: The detection signal access module, the signal attenuation and protection module, and the peak voltage detection module correspond to each other one by one, and each path corresponds to a detection channel; The input end of the detection signal access module is connected to the detected contact, and the output end is connected to the input end of the signal attenuation and protection module; The signal attenuation and protection module attenuates the voltage of the input detection signal by a fixed multiple; the output end of the signal attenuation and protection module is connected to the input end of the peak voltage detection module; The peak voltage detection module captures and maintains the peak voltage of the positive and negative pulses from the attenuated detection signal and converts it into an analog DC voltage; the output end of the peak voltage detection module is connected to the input end of the voltage acquisition module; The voltage acquisition module converts the input analog DC voltage sampling into a peak voltage value; the output end of the voltage acquisition module is connected to the input end of the data display and storage module; The data display and storage module is used to display and record the peak voltage value of each detection channel in real time, and locate and report the position of the risk source according to the peak voltage value.

2. The EOS peak voltage detection device according to claim 1, characterized in that: The device also includes a power module and a power conversion module; The power supply module provides power for the device; the output end of the power supply module is connected to the input end of the power conversion module; The power conversion module converts the output voltage of the power module into the operating voltage of the peak voltage detection module and the voltage acquisition module; the output end of the power conversion module is connected to the power input end of the peak voltage detection module and the power input end of the voltage acquisition module.

3. The EOS peak voltage detection device according to claim 2, characterized in that: The signal attenuation and protection module comprises a first resistor (R1), a second resistor (R2), a third resistor (R3), and a bidirectional TVS tube (TVS1); one end of the first resistor (R1) is connected to the output end of the detection signal input module, and the other end is respectively connected to the second resistor (R2) and the third resistor (R3); the other end of the second resistor (R2) is respectively connected to the bidirectional TVS tube (TVS1) and the input end of the peak voltage detection module; the other end of the third resistor (R3) is grounded; the other end of the bidirectional TVS tube (TVS1) is grounded; the resistance values ​​of the first resistor (R1) and the second resistor (R2) are equal.

4. The EOS peak voltage detection device according to claim 2, characterized in that: The peak voltage detection module includes a positive peak voltage detection circuit and a negative peak voltage detection circuit.

5. The EOS peak voltage detection device according to claim 4, characterized in that: The positive peak voltage detection circuit includes a first operational amplifier (U1A), a second operational amplifier (U1B), a first diode (D1), a second diode (D2), a third diode (D3), a fourth resistor (R4), a fifth resistor (R5), a sixth resistor (R6), a first capacitor (C1), and a second capacitor (C2); The same-direction end of the first operational amplifier (U1A) is connected to the output end of the signal attenuation and protection module, and the reverse end of the first operational amplifier (U1A) is connected to the reverse end of the second operational amplifier (U1B) through the fourth resistor (R4); the reverse end of the first operational amplifier (U1A) is also connected to the anode of the first diode (D1), the cathode of the first diode (D1) is connected to the output end of the first operational amplifier (U1A), and the first capacitor (C1) is connected in parallel with the first diode (D1); The output end of the first operational amplifier (U1A) is also connected to the anode of the second diode (D2), the cathode of the second diode (D2) is connected to the anode of the third diode (D3), and the cathode of the third diode (D3) is respectively connected to the sixth resistor (R6) and the same direction end of the second operational amplifier (U1B); the other end of the sixth resistor (R6) is grounded; the cathode of the second diode (D2) is also connected to the output end of the second operational amplifier (U1B) via the fifth resistor (R5); the second capacitor (C2) is connected in parallel to the sixth resistor (R6); the reverse end of the second operational amplifier (U1B) is connected to the output end of the second operational amplifier (U1B); The positive and negative power pins of the first operational amplifier (U1A) and the second operational amplifier (U1B) are connected to the output end of the power conversion module; the output end of the second operational amplifier (U1B) is connected to the input end of the voltage acquisition module.

6. The EOS peak voltage detection device according to claim 4, characterized in that: The negative peak voltage detection circuit includes a third operational amplifier (U2A), a fourth operational amplifier (U2B), a fifth operational amplifier (U3B), a fourth diode (D4), a fifth diode (D5), a sixth diode (D6), a seventh resistor (R7), an eighth resistor (R8), a ninth resistor (R9), a tenth resistor (R10), an eleventh resistor (R11), a twelfth resistor (R12), a third capacitor (C3), and a fourth capacitor (C4); The same-direction end of the third operational amplifier (U2A) is connected to the output end of the signal attenuation and protection module, and the reverse end is connected to the reverse end of the fourth operational amplifier (U2B) through the seventh resistor (R7); the reverse end of the third operational amplifier (U2A) is also connected to the cathode of the fourth diode (D4), the anode of the fourth diode (D4) is connected to the output end of the third operational amplifier (U2A), and the third capacitor (C3) is connected in parallel with the fourth diode (D4); The output end of the third operational amplifier (U2A) is also connected to the cathode of the fifth diode (D5), the anode of the fifth diode (D5) is connected to the cathode of the sixth diode (D6), the anode of the sixth diode (D6) is respectively connected to the ninth resistor (R9) and the same direction end of the fourth operational amplifier (U2B); the other end of the ninth resistor (R9) is grounded; the anode of the fifth diode (D5) is also connected to the output end of the fourth operational amplifier (U2B) via the eighth resistor (R8); the fourth capacitor (C4) is connected in parallel with the ninth resistor (R9); the reverse end of the fourth operational amplifier (U2B) is connected to the output end of the fourth operational amplifier (U2B); The output end of the fourth operational amplifier (U2B) is connected to the reverse end of the fifth operational amplifier (U3B) via the tenth resistor (R10); the positive end of the fifth operational amplifier (U3B) is grounded via the twelfth resistor (R12); the reverse end of the fifth operational amplifier (U3B) is connected to the output end of the fifth operational amplifier (U3B) via the eleventh resistor (R11); The positive and negative power pins of the third operational amplifier (U2A), the fourth operational amplifier (U2B), and the fifth operational amplifier (U3B) are connected to the output end of the power conversion module; the output end of the fifth operational amplifier (U3B) is connected to the input end of the voltage acquisition module.

7. The EOS peak voltage detection device according to claim 2, characterized in that: The power module is a USB interface power supply of a computer.

8. The EOS peak voltage detection device according to claim 1, characterized in that: The voltage acquisition module is a single chip microcomputer.

9. The EOS peak voltage detection device according to claim 1, characterized in that: The data display and storage module uses the SSCOM serial port debugging assistant running on the computer to display and record the EOS peak voltage of each detection channel.

10. The EOS peak voltage detection device according to claim 1, characterized in that: The detection signal access module includes two BNC connectors and a copper cable connecting the two BNC connectors, wherein one of the BNC connectors is connected to the input end of the signal attenuation and protection module, and the other BNC connector is connected to the detected contact and a reference ground.

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