1. For a product that has been designed, how to use an oscilloscope to detect and analyze its reliability?

Answer: The oscilloscope has long been regarded as one of the most useful tools for evaluating electrical circuits. You may visually examine whether the circuit is working properly and evaluate whether the design is appropriate by looking at the voltage and current waveforms of important nodes in the circuit. This is incredibly beneficial in terms of increasing reliability. Of course, the engineer's own experience plays a role in the right waveform analysis and judgment.

2. What are the main factors that determine the price of oscilloscope probes?

Answer: Oscilloscope probes come in a variety of configurations, including high voltage, differential, active high-speed probes, and more, with prices ranging from a few hundred RMB to nearly $10,000 USD. The most important price factors are, of course, bandwidth and features. The oscilloscope probe is the portion of the instrument that makes contact with the circuit. A decent probe can give the testing fidelity needed. Even passive probes must contain a large number of passive component compensation circuits (RC networks) to achieve this.

3. In general, how long is the service life of Keysight oscilloscope probes? Does the probe need to be calibrated regularly?

Answer: The life of an oscilloscope probe is difficult to predict because it is dependent on the environment and mode of use. Although there are no defined measurement criteria for probes in the standard, probe compensation adjustments must be done for passive probes, at least when the probe is replaced or the probe is exchanged channels. Warm-up all active probes for at least 20 minutes before using. For zero drift, some active probes and current probes must be modified.

4. What is the real-time sampling rate of the oscilloscope?

Answer: The reciprocal of the sample interval of one acquisition (one trigger) of the oscilloscope is the real-time sampling rate. The simultaneous use of four channels is thought to be the present industry's maximum level.

5. What is the equivalent time sampling of an oscilloscope?

Answer:Equivalent time sampling describes how the oscilloscope combines waveforms from numerous acquisitions (triggers) into a single waveform. The sample rate may be extremely slow each time, and the trigger point of the two acquisitions may be offset slightly, resulting in a final result. The equivalent sampling rate is the reciprocal of the minimum sampling interval between two points. It has a very high index, such as 1ps.

6. What is power factor? How to measure?

Answer: The active power of a DC circuit is equal to the voltage multiplied by the current. In an AC circuit, however, the apparent power is equal to the voltage multiplied by the current, and the fraction of the power that may perform work (i.e., the active power) will be less than the apparent power. The power factor, which is denoted by COS, is the ratio of active power to perceived power. In reality, the most basic approach for determining power factor is to measure the phase difference between voltage and current.

7. How to express and test the power density?

Answer: The power density is defined as the amount of energy per unit of volume. W/in3 is commonly used in power supplies.

8. Is there a way to use an oscilloscope to measure the working conditions of high-frequency transformers or inductance cores?

Answer: The analysis of the B-H curve is a function in the TEK power test software that can reflect the operating state of the magnetic core, as well as measure the dynamic inductance value and calculate the magnetic core loss.

9. There are many kinds of noise of switching power supply, such as cross interference caused by unreasonable wiring, inductance leakage, diode reverse spikes, etc., which cause noise. How to identify it with an oscilloscope?

Answer: The TDS5000 oscilloscope from TEK has frequency domain analysis and analysis of the noise's frequency band, which can determine the type of noise and the appropriate processing procedure. The oscilloscope can only analyze data and show it in a band-shaped pattern.

10. How can LeCroy oscilloscope test the radiation of the initial power supply?

Answer:Radiation interference is present in the switching power supply. The typical approach is to try to locate and shield the source of the interference. The Fourier transform function on an oscilloscope can be used to study the frequency component composition and determine the type of interference based on the frequency range.

11. The transformer's conversion efficiency is frequently degraded in the flyback power supply design process due to the transformer's substantial leakage inductance. The secondary winding procedure in the middle of the primary is still not perfect. Is there a method for winding transformers?

Answer: To enhance the connection, coil the high-power output winding inside, as close as feasible to the original side.

12. Is there an oscilloscope that can analyze the switching loss?

Answer: The TDS5000 series digital phosphor oscilloscope with TDSPWR2 power analysis software from Tektronix can readily measure switching loss and power loss per cycle, even with RDS ON.

13. Can the oscilloscope perform Fourier decomposition?

Answer: The FFT feature is found in most modern digital oscilloscopes, and the systems indicated above can even pre-test current harmonics according to EN61000-3-2 requirements.

14. Can the oscilloscope perform filtering processing? Such as low-pass filtering of the PWM wave?

Answer: TDS5000 can conduct low-pass filtering at 20MHz and 150MHz, as well as digital low-pass filtering known as high-resolution acquisition. The vertical resolution of sampling points can be enhanced from 8 bits to 12 bits in this mode. The system outlined above It is possible to generate a sine wave-like waveform in which a signal, such as PWM, varies in response to the pulse width trend.

15. When using a digital oscilloscope, what are the principles for setting the B trigger and trigger level and the signal under test?

Answer:A and B trigger functionalities are available on Tektronix oscilloscopes. Simply said, a dual event sequence can set it off. When the A-B seq option is chosen, event A serves as the main trigger, while event B captures complicated waveforms. The A event arm trigger system is the trigger method, and it is triggered at the B event when the designated B event occurs. Please refer to the oscilloscope's handbook for comprehensive trigger instructions.

16. How to use TDS3052B to measure the maximum value of the modulated wave whose carrier frequency is dozens of K and the modulating wave frequency is the power frequency?

Answer: The carrier may be tens of K, and the power frequency cycle is around 20ms. The power frequency input may be low frequency 50Hz/60Hz. If the oscilloscope is required to monitor a 20ms signal, the oscilloscope's duration acquisition window must be at least 2ms/div 10 divisions. Determine the oscilloscope's sample rate based on the carrier signal in tens of k at the same time. Finally, the acquisition memory length required can be estimated to see if it meets the test requirements.

17. Using a nominal 100MHz DSO oscilloscope, measure a high-frequency switch amplitude of 400V, f=50M, how does the oscilloscope plot its waveform and rise time?

Answer: You can start from the following aspects:

①The sine wave amplitude attenuation -3dB point is used to determine the oscilloscope's bandwidth.

② In a digital oscilloscope, the waveform and rise time are drawn using a real-time sampling circuit and a high-speed A/D converter to obtain waveform data, which is then interpolated.

③ A real-time processing circuit of the Tektronix oscilloscope completes the so-called sine interpolation function, which is accomplished in the signal acquisition circuit component. Of course, many oscilloscopes are also finished by the oscilloscope's main processor for mathematical operations, which takes a long time.

④ I'm afraid a 100MHz oscilloscope will not be able to measure the signal you're measuring. In theory, for a 50MHz square wave, an oscilloscope with a bandwidth greater than 450MHz should be used to precisely recreate the signal's most essential harmonics below the 9th order, ensuring that the waveform is not deformed. Furthermore, the signal rising time may need to be considered. The oscilloscope's rise time should, in theory, be more than 5 times faster than the signal.

⑤ The same can be said with probes. Because regular probes exhibit high-frequency distortion when measuring high voltages, special differential probes or high-voltage probes, such as the Tektronix P5205 and P5100, should be used instead.

18. How to make good use of digital oscilloscope in analog circuit, such as measuring small signal of audio amplifier, noise of power supply, etc.?

Answer: The issues to be aware of are:

①The oscilloscope's grounding difficulty, because the oscilloscope's chassis and the probe's reference ground wire are both connected to the ground wire, good grounding is the key condition for monitoring interference.

② The oscilloscope's reference ground cable introduces an interference problem. Because most common probes have a segment of ground wire, it will construct an interference path with the spot to be measured, similar to a loop antenna, and introduce quite large interference. As a result, it's critical to keep this interference to a minimum. Remove the probe cap, do not utilize the ground wire drawn from the probe, and touch the point to be measured directly with the probe tip and the spot inside the probe for measurement.

③ To eliminate common mode noise, use differential measurement. Differential probes are available from Tektronix. The ADA400A, for example, can measure hundreds of microvolts, while the P7350, designed for high-speed signal measurement, has a bandwidth of up to 5GHz.

④ Many Tektronix oscilloscopes provide a high-resolution acquisition (Hi-Res) signal capture mode that can filter out random noise.

19. When measuring the conduction disturbance of the off-board signal line, it was found that there are two large noise signals at two specific frequency points (one is 659K and the other is 1.977K). The preliminary analysis is caused by the switching power supply chip on the board. How to use an oscilloscope to measure such noise signals?

Answer: When using an oscilloscope to test noise signals, there are a few things to keep in mind:

① Whether the signal under test has a large or small amplitude, the oscilloscope and probe can examine uA? level signals.

② The frequency of the signal that is being measured.

③An improper probe connection will cause noise, which will influence the test findings.

20. How to understand the Holdoff parameter when using Tektronix oscilloscopes?

Answer: Holdoff (trigger holdoff) is the process of momentarily closing the oscilloscope's trigger circuit for a length of time (ie, holdoff time). Even if there are signal waveform points that fulfill the trigger conditions during this time, the oscilloscope will not activate. It's also stated as a % in a digital oscilloscope, which implies the percentage of the whole record length or screen.

The trigger part of the oscilloscope's job is to show the waveform stably, and the trigger holdoff is another function adjusted for waveform stability. It is designed for the repeating of a long period, and there are several non-repetitive waveform places in the long period that match the trigger condition. The red dots in the picture, for example, can meet the trigger conditions, as shown. The trigger point will not be fixed if the holdoff function is not used, causing the display to be unsteady. After employing the trigger holdoff, it will always activate at the same time, allowing it to be displayed consistently. Additionally, trigger holdoff is used in AM signals.

21. Regarding holdoff, what is the difference between the so-called trigger and non-trigger processing of the acquired signal by the oscilloscope?

Answer: Regardless of whether a digital oscilloscope is triggered or not, it is continuously accumulating waveforms, but only a steady trigger can provide a stable display. This can also happen if the oscilloscope trigger circuit is set to "auto" mode, which means the waveform is displayed regardless of whether the trigger requirements are met. If the trigger requirements are not met when using the "normal" Normal mode, the waveform will not be displayed.

22. Is the bigger the percentage setting (related to the signal display gradually stabilizing) the longer the signal period if the horizontal time resolution remains unchanged?

Answer: Yes, the larger the percentage, the longer the holdoff time.

23. How to use an oscilloscope to measure differential signals?

Answer: If you don't have a differential probe, you can use two differential probes to connect to the two channels of the oscilloscope (such as Ch1, Ch2), and then use mathematics Calculate to get the waveforms of ch1-ch2 and analyze them; if you don't have a differential probe, you can use two differential probes to connect to the two channels of the oscilloscope (such as Ch1, Ch2), and then use mathematics Calculate to get the waveforms of At this point, attempt to keep the two probes same and the vertical scale (number of volts per division) of the two oscilloscope channels identical; otherwise, the mistake will be greater.

24. How to measure the differential signal on the USB bus with an oscilloscope?

Answer: The USB signal test is divided into two situations:

The first step is to complete the physical layer test standard, which must conform to the USB 1.1/2.0 bus as established by the USB organization, and the USB logo can only be applied when the USB conformance test has been passed. Signal Quality Test, Droop & Drop Test, Inrush Current Test, HS Specific Tests, Chirp Test, Monotonic Test, Receiver sensitivity Test, Impedance Test (TDR), and so on are all part of the USB physical layer conformance test, which examines the signal quality of the USB signal.

To examine solely the signal on the USB bus in the second situation, connect an appropriate differential probe to D+ and D- and observe the USB signal directly. The rising time for the USB2.0 signal is several hundred picoseconds, which is relatively quick. An oscilloscope and a differential probe with a frequency greater than 2GHz must be used for testing to assure signal fidelity.

25. High-speed signal characteristics on the PCB: XAUI interface 3.125GBd serial differential signal: 60ps, how high bandwidth oscilloscope is needed to accurately measure? What is the measurement error?

Answer: The XAUI interface's 3.125GBd serial differential signal sounds a lot like an InfiniBand transmission. It is collected via sinusoidal interpolation or comparable sampling, however it is measured at 100ps due to its own bandwidth and trigger jitter. The 7GHz differential probe can ensure a 3% inaccuracy when the rise time is in the range of 130ps. The error will be larger than 10% for a rising time measurement of 80ps. Despite the fact that this is the best solution for real-time oscilloscopes, it is just going to get better. Because its bandwidth may reach 50GHz, Keysight's network analyzer (with physical layer analysis software) is the most precise solution in terms of time measurement.

26. For designs that have high requirements on the phase noise parameters of the clock, what are the key issues that need to be considered to reduce the phase noise?

Answer: Number of bits, conversion speed, DC accuracy, switching performance, dynamic performance (SNR, SINAD, IMD), and other indicators are used to evaluate the performance of ADC and DAC devices.

27. How to measure the phase noise in a design that has high requirements on the phase noise parameters of the clock?

Answer: You may examine the amplitude, time, converted signal quality, conversion speed, clock and data setup/hold time, and other characteristics of ADC and DAC analog and digital signals with an oscilloscope. You can also use the TDS oscilloscope to test the parameters. SNR, SINAD, and other parameters can be measured qualitatively using the advanced calculation tool (spectrum analysis function).

28. Since it may be necessary to introduce an external clock, so the clock has the problem of choosing one from two. What solution can be used to minimize the deterioration of phase noise?

Answer: First, figure out what's causing the jitter. Jitter can be detected with oscilloscopes. You may now use TDS5000B/6000B/7000B series oscilloscopes with jitter analysis software to perform comprehensive jitter analysis, such as detecting jitter (Dj), random jitter (Rj), separating Rj and Dj, and eventually eliminating jitter by examining the cause of jitter.

29. When viewing waveforms on an oscilloscope, what is the difference between using external trigger and self-triggering?

Answer: An oscilloscope's most common trigger is edge trigger. Trigger level and trigger edge are the two trigger conditions; the oscilloscope triggers when the signal's rising edge (or falling edge) reaches a specific level (trigger level). When there is a difficulty with the signal self-triggering, the oscilloscope will use external triggering. There isn't a more pressing issue. However, this type of issue is more likely to occur when the signal is more intricate, there are multiple places that fulfill the trigger parameters, and it is impossible to trigger at the same position every time in order to achieve a stable display. You'll need to use an external trigger at this point. As an example, consider the following: Take note of the indication shown above. The waveform seen by the oscilloscope will not be stable since each point of ABCD will trigger. You can use the following signal as the trigger signal at this point, and the oscilloscope will display a full cycle.

30. The TDS3032B has a 300MHz bandwidth, a 2.5G/s sampling frequency, and a sampling frequency that is 8 times the bandwidth. What is the fixed relationship between sampling frequency and bandwidth? An oscilloscope from another manufacturer, such as a Tektronix oscilloscope, is also available. The sample frequency is just 200MHz, and the bandwidth is 100MHz. Why is there such a disparity between the bandwidth sampling frequency ratios of the two oscilloscopes?

Answer: The most essential indicator of an oscilloscope is its bandwidth. Because a digital oscilloscope has an ADC, the sampling rate must theoretically follow the Nyquist sampling law, which states that at least two points must be gathered for each cycle of the highest frequency signal of the observed signal. Otherwise, aliasing will occur. However, numerous other elements, such as the waveform reconstruction algorithm, play a role. Advanced waveform reconstruction techniques are used in Tektronix oscilloscopes, and each cycle of the signal under examination only requires 2.5 points to reconstruct the waveform. Some oscilloscopes use linear interpolation techniques, which can take up to ten points to complete. The waveform can be reproduced more accurately when the sampling rate is 4 to 5 times the bandwidth.

The Tektronix TDS3000B series oscilloscopes are "real-time sampling," which means that their single bandwidth (capable of capturing a single signal) = repeat bandwidth. As you can see, the single bandwidth of the other oscilloscope you described is clearly less than 100MHz. Let's look at some of the indications.

31. How to understand the bandwidth in the oscilloscope index?

Answer:An oscilloscope's basic indicator is bandwidth. The so-called -3dB point, that is, the frequency point at which a sine wave is fed to the oscilloscope's input and the amplitude is reduced to 70.7 percent of the real amplitude, is called bandwidth, same as the definition of amplifier bandwidth. In other words, when a 1V, 100MHz sine wave is measured with a 100MHz bandwidth oscilloscope, the amplitude recorded is only 0.707V. This only applies to sine waves. As a result, in order to obtain a specific level of measurement accuracy, we should use an oscilloscope with a bandwidth that is 5 times the highest signal frequency.

32. How to obtain the total bandwidth of the measurement system?

Answer: The total bandwidth of the measurement system = 0.35/rise time (oscilloscope below 1GHz).

33. Under the condition of a certain bandwidth, does it mean that the sampling frequency is too large?

Answer: The essential constraint limiting the acquisition of high-frequency components of the signal under test is bandwidth. To maximize the waveform reconstruction with Tektronix oscilloscopes, only 2.5 points per observed signal cycle are required. Some oscilloscopes require more than 4 samples per period, for example, a 100MHz bandwidth oscilloscope requires at least 400MS/s for a single acquisition, and some oscilloscopes even require 10 points (linear interpolation technique) to ensure that the obtained signal is meaningful.

34. When choosing an oscilloscope, bandwidth is generally considered. So, under what circumstances should the sampling rate be considered?

Answer: It is dependent on the object being tested. On the assumption that the bandwidth is met, the minimum sampling interval (the reciprocal of the sample rate) should be able to capture the signal information you require. In the industry, there are some empirical sampling rate formulas, however they are all depending on the oscilloscope's bandwidth. It is advisable not to use an oscilloscope to measure signals of the same frequency in practical applications. If you're using a sine wave, set the oscilloscope's bandwidth to three times the frequency of the sine signal being evaluated. The bandwidth is actually 12 to 15 times the signal, hence the sampling rate is 4 to 5 times the bandwidth. You must ensure that the sampling rate is sufficient to capture signal details for other waveforms. If you're using an oscilloscope, you can use the methods below to see if the sampling rate is adequate. Stop the waveform and make it bigger. If there is a change in the waveform (such as amplitude), the sampling rate is insufficient; otherwise, everything is good. The point display can also be used to determine if the sample rate is enough.

35. In addition to Gaussian response oscilloscopes and flat response oscilloscopes, are there any oscilloscopes based on other responses?

Answer:The analog device determines the frequency response characteristic of the oscilloscope preamplifier, which is the most important aspect in determining the test outcome. The trick is to figure out which strategy is employed to get a good frequency response.

36. Passive probes (such as P6139A, bandwidth 500M) were utilized with TDS744, TDS745 and other oscilloscopes. The test results of the two after acquiring the active probe (P6237) are considerably different in terms of the test waveform (particularly when monitoring high-frequency signals). The active probe's input capacitance is about 1pF, whereas the passive probe's is roughly 10pF, according to the probe specifications. As a result, it appears that the active probe's test findings better match the signal's real-world state. What does the 500M bandwidth signify, given how much the passive probe attenuates high-frequency signals? How? To employ active or passive probes depending on the test situation?

Answer: Your P6139A probe's normal bandwidth combined with Tektronix's 500MHz oscilloscope can still reach 500MHz, however its input capacitance is different, as you mentioned. This capacitance will cause a load impact on the signal under test, generating ringing and signal shape distortion. Changes have occurred, and when the active probe is utilized at this time, the true state of the signal may be seen. In fact, when utilizing probes to measure high-frequency signals, all of these characteristics must be taken into account, not only bandwidth:

Dynamic range, load effect, grounding impact, and resonance effect are all factors to consider.

Especially for P6139A, you should additionally consider the influence of the ground wire. Ringing can also be caused by the probe's ground wire. When measuring high-frequency signals, attempt to keep the ground wire as short as possible.

Furthermore, because the P6247 you're using is an active differential probe, common mode could be a concern. The high dynamic range of a passive probe is the major rationale for using it. P6139A, for example, can measure signals ranging from millivolts to hundreds of volts, but P6247 can only measure +-8.5V signals. The cost of active probes is also a consideration.

37. During the experiment, after the ground wire of the oscilloscope, the MOsfet was blown up. Now the ground wire of the oscilloscope is cut off. What is the reason?

Answer: The ground wires of all oscilloscope probes are normally linked to the case and connected to the ground wire of the oscilloscope's power cable in order to ensure personal safety during testing and produce good measurement results. As a result, if any of the points in the MOSFET waveform in the power supply is not grounded, difficulties will arise.

Cutting the ground wire may prevent the short circuit problem in the MOSFET test, but it will also cause other test issues, such as oscilloscope case electrification and the influence of the oscilloscope case distribution parameters on the measurement signal. A differential probe, such as the Tektronix P5205, can be used to measure the so-called differential signal, which has two test points that are not grounded.

38. When using an oscilloscope to capture data, it's discovered that just the data from the current screen is saved in the recorded text, and the time interval is determined by the resolution. How to use real-time data processing software (matlab? ), and how to gather more data?

Answer: The compressed screen display style is used by Tektronix oscilloscopes, which means that the waveform displayed on the screen represents all of the gathered data. All waveforms can be simply viewed using the TDS5000B's multiViewZoom capability. The Tektronix TDS5000B, TDS6000, TDS7000B, and TDS8000B series oscilloscopes all run on a completely open WINDOWS platform and support all current popular tools for data analysis and processing, such as Matlab, LabView, VB, VC,.NET, MicroSoft Office VBA, and others.

These analysis tools can also be put directly in the oscilloscope, resulting in a device that combines data gathering, analysis, display, and processing. To gather more data in a given amount of time, the oscilloscope must have a larger memory depth. The TDS5000B series general oscilloscope, for example, may support up to 16M memory.

39. When using analog and digital oscilloscopes to observe the details of the waveform, which one is more advantageous (for example, when observing the spurious waveform below 1% at the zero-crossing point and peak value)?

Answer: Look for the parasitic waveform below 1%. The observation accuracy of an analog oscilloscope or a digital oscilloscope is not very excellent. An analog oscilloscope's vertical precision may not be as good as a digital oscilloscope's. For example, a 500MHz bandwidth analog oscilloscope's vertical accuracy is +/ 3%; it is not more advantageous than a digital oscilloscope (usually 12 percent accuracy), and for details, a digital oscilloscope's automatic measurement function is more accurate than an analog oscilloscope's manual measurement.

40. Our program typically takes 2M or more data for analysis, with a sampling rate of up to 10GS/S, yet when conducting parameter testing and FFT analysis, it always appears to be very slow. Why?

Answer:Because there is a lot of data to process, the speed will be slow. Unless a specialist FFT processor is utilized, the expense of obtaining high-speed real-time FFT analysis of big data volumes is relatively significant.

41. How does the <a href="https://www.utmel.com/blog/categories/measurement/how-to-use-the-oscilloscope" s-x-y-display-correctly'="" style="box-sizing: border-box; margin: 0px; padding: 0px; color: rgb(64, 102, 184); text-decoration-line: none; font-size: 14px;">oscilloscope display the waveform between two sampling points?

Answer: The oscilloscope has several display modes: point display, sine interpolation display, and straight line connection display; the default display mode is usually the vector connection display mode, and some oscilloscopes only support the straight line connection mode; regardless of whether it is a straight line connection or a sine connection Interpolation, the information provided between the two actual sampling points is not actually collected. The display may appear abrupt due to the straight-line connecting approach. Although a triangle wave is shown, it is still a sine wave due to sine interpolation. As a result, some application papers claim that using a straight line connection necessitates a higher sampling rate, such as a 10 times relationship (to accurately recreate the waveform in real life); using sine interpolation necessitates a slightly lower sampling rate. According to some sources, 2.5 times is sufficient. It is commonly said in engineering that it is 4 times or more, although there are also 5 times and 6 times.

42. I want to measure the case where the interference signal from the main power supply enters the power supply of the weak signal amplifier to solve the problem of anti-power supply interference. As a result, there are interference signals even when the oscilloscope probe is attached to the ground, regardless of where it is measured. The audio signal is causing the interference. Why is it the case?

Answer: The issues to be aware of are:

① The oscilloscope's grounding difficulty, as the oscilloscope's chassis and the probe's reference ground wire are all connected to the ground wire, good grounding is the essential condition for measuring interference;

②The oscilloscope's reference ground cable introduces an interference problem. Because most common probes have a segment of ground wire, it will construct an interference path with the spot to be measured, similar to a loop antenna, and introduce quite large interference. As a result, it's critical to keep this interference to a minimum. The method is to remove the probe cap, not to utilize the ground wire drawn from the probe, but to connect the point to be measured directly with the probe tip and the place inside the probe for measurement;

③ To eliminate common mode noise, use differential measurement. Differential probes are available from Tektronix. For example, the ADA400A, which is designed for small signals, can measure hundreds of microvolts, while the P7350, which is designed for high-speed signal measurement, has a bandwidth of up to 5GHz.

④Many Tektronix oscilloscopes provide a high-resolution acquisition (Hi-Res) signal capture mode that can filter out random noise.

43. During an EMC test, the sign may vanish for a brief period of time. The oscilloscope is utilized for testing, and it is discovered that throughout the test, the oscilloscope shakes the entire screen. EFT is the test item (Transient Pulse Train Immunity Test). How can this phenomenon in the test be explained and eliminated?

Answer: EFT can occasionally generate oscilloscope interference and false triggers. To limit the oscilloscope's bandwidth, try using the oscilloscope's high-frequency suppression trigger mode.

44. Why does the oscilloscope sometimes fail to capture the amplified current signal?

Answer:If the signal exists but the oscilloscope can sometimes catch it and sometimes can't, it could be due to the oscilloscope's settings. When the oscilloscope's trigger mode is set to Normal, the trigger condition is set to edge trigger, the trigger level is adjusted to a suitable value, and the sweep mode is set to single mode, the oscilloscope's trigger mode is usually set to Normal. If this mode does not work, the instrument is likely to have a problem.

45. If the bandwidth is determined based on the signal rise time, is the principle of determining the sampling rate based on the bandwidth just to achieve no sampling aliasing error?

Answer: After the bandwidth has been calculated, the sampling rate is determined. Some industry formulas do indeed determine the sampling rate principle to achieve no sampling aliasing error, but this is a broad statement that depends on the characteristics of your measured object, because the highest index is often given under specific conditions that may not meet your test application.

46. Does the new digital oscilloscope 54621A and 54621D have any influence on the different signals and different speeds of the (Inter-IC) bus during testing?

Answer: Signals on the I2C Bus typically operate at a rate of 400Kbit/s or less. A few Mbit/s semiconductors have recently been available. There is no need to consider the influence of differing rates when setting trigger conditions for 54621A and 54621D, but you must first specify the current actual working rate of the CAN bus on the oscilloscope so that the oscilloscope can accurately decode the agreement and trigger correctly.

47. In addition to oscilloscopes 54621A and 54621D, what other instruments can detect and analyze Inter-IC bus signals?

Answer: You can utilize Keysight's logic analyzer to perform more advanced analysis on Inter-IC bus signals, such as protocol-level analysis, although the price is more than the 54621A/D.

48. The various trigger applications of digital oscilloscopes, such as edge trigger, glitch trigger and pulse width trigger, are they suitable for testing what kind of signal?

Answer: ①edge trigger, edge trigger, rising edge or falling edge, you can set the trigger level. Basic trigger is another name for edge trigger.

② Advanced trigger, i.e. advanced trigger, which encompasses a wide range of trigger functions. You can configure the corresponding trigger conditions to locate the waveform of interest based on the features of the signal under test. Circuit debugging relies heavily on advanced triggering. If you don't know the potential difficulties with the signal under test ahead of time, you can use the Tektronix digital phosphor oscilloscope to quickly detect numerous flaws in the circuit with a waveform capture speed of 400,000/sec, and then work with many advanced trigger features. Perform precise fault location to speed up your debugging process.

49. Regarding the burr measurement, I have consulted relevant technical personnel before, and the answer is that the smallest burr that the oscilloscope can capture is the sampling rate of the oscilloscope. Do all oscilloscopes follow this rule? Will the pre-filter of the oscilloscope affect it at this time?

Answer:This does not mean that all oscilloscopes are the same. Some oscilloscopes, for example, may attain 1GS/s while only having a bandwidth of 60MHz. 1ns faults are obviously impossible to capture. In fact, not only does bandwidth and sampling rate affect the capacity to catch glitches, but so does waveform capture rate, or the number of waveforms that can be collected each second. Please see Tektronix's application article on DPO for further information.

50. How to eliminate glitches when using an oscilloscope?

Answer:If the glitch is in the signal itself and you wish to use an edge trigger to synchronize it (such as a sinusoidal signal), you can utilize the high-frequency suppression trigger mode to synchronize the signal. It's frequently difficult to get the oscilloscope to filter out the glitches without revealing the glitches if the signal itself has problems.

You can try to reduce the bandwidth, but if you're not careful, you might end up filtering out some of the signal. When using a logic analysis instrument, employ the state acquisition approach in general, as some glitches gathered in the timing mode will not be visible.