【 Weak current College 】 oscilloscope selection considered ten factors 】

You rely on every day, select the appropriate oscilloscope oscilloscope to meet your needs is an important task.

How much bandwidth you need

Bandwidth is the most important characteristics of an oscilloscope, because it determines the display range of the signal, to a large extent also decided that the user needs to pay the price. Setting bandwidth when you need to make decisions on the budgetary and oscilloscope using period projected demand balance. System clock is oscilloscope may display the maximum signal frequency. Oscilloscope bandwidth at least should be better than this one frequency high three times to reasonably show this signal shape. Decision oscilloscope bandwidth requirements of another signal characteristics is the signal rise time. This is a very simple formula to help you according to the signal characteristics determine the appropriate oscilloscope bandwidth.
1. signal bandwidth = 0.5/signal rise time; 2. oscilloscope bandwidth = 2 × signal bandwidth; 3. oscilloscope real-time sampling rate = 4 × oscilloscope bandwidth

How many channels you want
　
Traditional 2 channel or 4 channel oscilloscope does not trigger has been provided and view all interested signals the necessary number of channels. But the industry's emerging oscilloscope-mixed signal oscilloscope (MSO) in addition to the typical oscilloscope 2 or 4 analog channels, the also closely into another 16 logical timing channel. Enables full-featured oscilloscope, providing up to 20 time-correlated to trigger, capture and viewing channel.

You ask how much is the sampling rate of

In assessing the oscilloscope, the sampling rate is a very important consideration. Why? inserted in most Oscilloscopes, in the form of two or more channel coupling ADC, the only four-channel oscilloscope, one or two channels provide maximum sampling rate, which can improve the sampling rate. Oscilloscope's sampling rate is at least four times the bandwidth of the oscilloscope. Oscilloscope using a digital reconstruction of the form of time, it is best to use four times the multiplier, in oscilloscope does not use a digital reconstruction of the forms, the multiplier effect should be 10 times. But since most oscilloscope using some form of digital reconstruction, 4 times the forms should be sufficient. Determine the application of the resolution between hope is to consider the sampling rate in another way. The sampling rate is the reciprocal of the resolution.

You need the number of memory depth

Memory depth and sampling rate. Select an important when the oscilloscope is understanding how to use storage oscilloscope. Oscilloscope memory cards to all of the sampling rate can capture more of the time. Your required memory depth depends on the number of the monitor you want to view and want to keep the sampling rate. If you want to do the same points to higher resolution view the longer period, you need to use a deep memory: memory depth = sampling rate × display time. Determine memory depth, equally important is the need to visit the deepest in the use of memory when the oscilloscope is set.

What you need to display function

Oscilloscope display performance largely depends on the number of the algorithm, not the physical characteristics of the display device. Not a good way, through the study of oscilloscope specifications to determine which is most suitable for users of oscilloscope lab environment. Only in the user table live demos and use on the user's profile, you can determine which oscilloscope that meets user needs. Current digital oscilloscope into two broad categories: waveform viewing apparatus and waveform Analyzer. To view the waveform design Oscilloscopes typically used for testing and problem diagnosis, in these applications, the waveform image will provide users with all the required information.

What triggers the functionality you need
　　
Many General oscilloscope using edge trigger functionality. However, some applications may need to use other triggering capabilities. Advanced triggering feature allows you to isolate the events you want to view. At the advanced trigger option also to daily debugging tasks in saving a lot of time. If you need to capture a rare event, what would happen? Burr trigger allows triggering positive burrs or negative Burr, or trigger is greater than or less than the specified width of the pulse. Diagnose the problem, peculiar to use these features. You can trigger the problem, go back to view the result in the root of the problem.

Detection signal what is the best way to

When the signal changes in the rate exceed 1GHz due to passive probes are generally limited to get oscilloscope 600MHz, full bandwidth may be a problem. Active probes provide not only more than passive probe of bandwidth, but they also eliminate the probe connected to the device under test (DUT) part transmission line effects. By active probes in the resistance "attenuation" probes and accessories, Agilent Technologies minimize signal load and cause signal distortion. The attenuation of accessories can prevent L-C resonance circuit impedance becomes too low, so as to prevent loading of a signal lead to reduction of oscillation and signal distortion. Has now been resolved the signal distortion problem, if you detect a high-speed signal, then the next step is to ensure that even when you use the probe accessories are still able to achieve the full bandwidth.
Many Oscilloscopes with and the personal computer of the same interface, including GPIB, RS232, LAN and USB interface. Many Oscilloscopes also GB of hard drive, you can use it to store data. But the user should define in advance what programs need oscilloscopes provide connectivity and archiving features. If required as part of the automatic test system to connect an oscilloscope, make sure the oscilloscope with enough software and drivers, to adapt to your programming environment.

How to analyze waveforms

Automatically test and built-in analytics can save users time, make work easier, digital Oscilloscopes often with analog Oscilloscopes does not have to provide a range of measurement functions and analysis options. Math functions including add, subtract, multiply and divide, integral and differential. Measurement statistics (min-Sik, maximum and average values) can calibration measurement uncertainty, in characterizing noise and timing margin, this is an important resource. Many digital oscilloscope also provides FFT function。

Demo

Last, but it is equally important problem: demo, demos or presentations! if you have already considered the front nine factors, you may have to narrow to be able to meet the standards of a small amount of oscilloscope. Now you should use the oscilloscope, and compare. Use each simple oscilloscope attention to ease of use and display the response.