Keysight Technologies
`Basic Oscilloscope Fundamentals
`
`Application Note
`
`This application note provides an overview of basic oscilloscope
`fundamentals. You will learn what an oscilloscope is and how to use
`oscilloscopes. We will discuss oscilloscope applications and give you
`an overview of basic oscilloscope measurements and performance
`characteristics. We will also look at the different types of probes and
`discuss their advantages and disadvantages.
`
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`

`Introduction
`
`Electronic technology permeates our lives. Millions of people use electronic devices such as cell
`phones, televisions, and computers on a daily basis. As electronic technology has advanced,
`the speeds at which these devices operate have accelerated. Today, most devices use high-
`speed digital technologies.
`
`Engineers need the ability to accurately design and test the components in their high-speed
`digital devices. The instrumentation engineers use to design and test their components must
`be particularly well-suited to deal with high speeds and high frequencies. An oscilloscope is an
`example of just such an instrument.
`
`Oscilloscopes are powerful tools that are useful for designing and testing electronic devices.
`They are vital in determining which components of a system are behaving correctly and
`which are malfunctioning. They can also help you determine whether or not a newly designed
`component behaves the way you intended. Oscilloscopes are far more powerful than
`multimeters because they allow you to see what the electronic signals actually look like.
`
`Oscilloscopes are used in a wide range of fields, from the automotive industry to university
`research laboratories, to the aerospace-defense industry. Companies rely on oscilloscopes to
`help them uncover defects and produce fully-functional products.
`
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`03 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`Electronic Signals
`
`The main purpose of an oscilloscope is to display electronic signals. By viewing signals
`displayed on an oscilloscope you can determine whether a component of an electronic system
`is behaving properly. So, to understand how an oscilloscope operates, it is important to
`understand basic signal theory.
`
`Wave properties
`Electronic signals are waves or pulses. Basic properties of waves include:
`
`Amplitude
`
`Two main definitions for amplitude are commonly used in engineering applications. The first
`is often referred to as the peak amplitude and is defined as the magnitude of the maximum
`displacement of a disturbance. The second is called the root-mean-square (RMS) amplitude.
`To calculate the RMS voltage of a waveform, square the waveform, find its average voltage and
`take the square root.
`
`For a sine wave, the RMS amplitude is equal to 0.707 times the peak amplitude.
`
`peak amplitude
`
`RMS amplitude
`
`Figure 1. Peak amplitude and RMS amplitude for a sine wave.
`
`Phase shift
`
`Phase shift refers to the amount of horizontal translation between two otherwise identical
`waves. It is measured in degrees or radians. For a sine wave, one cycle is represented by
`360 degrees. Therefore, if two sine waves differ by half of a cycle, their relative phase shift is
`180 degrees.
`
`Period
`
`The period of a wave is simply the amount of time it takes for a wave to repeat itself. It is
`measured in units of seconds.
`
`Frequency
`
`Every periodic wave has a frequency. The frequency is simply the number of times a wave
`repeats itself within one second (if you are working in units of Hertz). The frequency is also the
`reciprocal of the period.
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`04 | Keysight | Basic Oscilloscope Fundamentals - Application Note
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`Electronic Signals (Continued)
`
`Period
`
`The period of a wave is simply the amount of time it takes for a wave to repeat itself. It is
`measured in units of seconds.
`
`period
`
`Figure 2. The period of a triangular wave.
`
`Frequency
`
`Every periodic wave has a frequency. The frequency is simply the number of times a wave
`repeats itself within one second (if you are working in units of Hertz). The frequency is also the
`reciprocal of the period.
`
`Waveforms
`A waveform is the shape or representation of a wave. Waveforms can provide you with a
`great deal of information about your signal. For example, it can tell you if the voltage changes
`suddenly, varies linearly, or remains constant. There are many standard waveforms, but this
`section will cover the ones you will encounter most frequently.
`
`Sine waves
`
`Sine waves are typically associated with alternating current (AC) sources such as an electrical
`outlet in your house. A sine wave does not always have a constant peak amplitude. If the peak
`amplitude continually decreases as time progresses, we call the waveform a damped sine wave.
`
`Figure 3. A sine wave.
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`05 | Keysight | Basic Oscilloscope Fundamentals - Application Note
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`Electronic Signals (Continued)
`
`Square/rectangular waves
`
`A square waveform periodically jumps between two different values such that the lengths of the
`high and low segments are equivalent. A rectangular waveform differs in that the lengths of the
`high and low segments are not equal.
`
`Figure 4. A square wave.
`
`Triangular/sawtooth waves
`
`In a triangular wave, the voltage varies linearly with time. The edges are called ramps because
`the waveform is either ramping up or ramping down to certain voltages. A sawtooth wave looks
`similar in that either the front or back edge has a linear voltage response with time. However,
`the opposite edge has an almost immediate drop.
`
`Figure 5. A triangular wave.
`
`Figure 6. A sawtooth wave.
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`06 | Keysight | Basic Oscilloscope Fundamentals - Application Note
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`Electronic Signals (Continued)
`
`Pulses
`
`A pulse is a sudden single disturbance in an otherwise constant voltage. Imagine flipping the
`switch to turn the lights on in a room and then quickly turning them off. A series of pulses is
`called a pulse train. To continue our analogy, this would be like quickly turning the lights on and
`off over and over again.
`
`Pulses are the common waveform of glitches or errors in your signal. A pulse might also be the
`waveform if the signal is carrying a single piece of information.
`
`Figure 7. A pulse.
`
`Complex waves
`
`Waves can also be mixtures of the above waveforms. They do not necessarily need to be
`periodic and can take on very complex wave shapes.
`
`Analog versus digital signals
`Analog signals are able to take on any value within some range. It is useful to think of an
`analog clock. The clock hands spin around the clock face every twelve hours. During this time,
`the clock hands move continuously. There are no jumps or discreteness in the reading. Now,
`compare this to a digital clock. A digital clock simply tells you the hour and the minute. It is,
`therefore, discretized into minute intervals. One second it might be 11:54 and then it jumps to
`11:55 suddenly. Digital signals are likewise discrete and quantized. Typically, discrete signals
`have two possible values (high or low, 1 or 0, etc.). The signals, therefore, jump back and forth
`between these two possibilities.
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`07 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`What Is an Oscilloscope and Why Do You Need One?
`
`Signal integrity
`The main purpose of an oscilloscope is to give an accurate visual representation of electrical
`signals. For this reason, signal integrity is very important. Signal integrity refers to the
`oscilloscope’s ability to reconstruct the waveform so that it is an accurate representation of
`the original signal. An oscilloscope with low signal integrity is useless because it is pointless
`to perform a test when the waveform on the oscilloscope does not have the same shape or
`characteristics as the true signal. It is, however, important to remember that the waveform on
`an oscilloscope will never be an exact representation of the true signal, no matter how good the
`oscilloscope is. This is because when you connect an oscilloscope to a circuit, the oscilloscope
`becomes part of the circuit. In other words, there are some loading effects. Instrument makers
`strive to minimize loading effects, but they always exist to some degree.
`
`What an oscilloscope looks like
`In general, modern digitizing oscilloscopes look similar to the one seen in Figure 8. However,
`there are a wide variety of oscilloscope types, and yours may look very different. Despite
`this, there are some basic features that most oscilloscopes have. The front panel of most
`oscilloscopes can be divided into several basic sections: the channel inputs, the display, the
`horizontal controls, the vertical controls, and the trigger controls. If your oscilloscope does not
`have a Microsoft Windows-based operating system, it will probably have a set of softkeys to
`control on-screen menus.
`
`Display
`
`Horizontal control section
`
`Trigger control
`section
`
`Vertical control
`section
`
`Softkeys
`
`Channel inputs
`
`Figure 8. Front panel on the Keysight InfiniiVision 2000 X-Series oscilloscope.
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`08 | Keysight | Basic Oscilloscope Fundamentals - Application Note
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`What Is an Oscilloscope and Why Do You Need One? (Continued)
`
`You send your signals into the oscilloscope via the channel inputs, which are connectors for
`plugging in your probes. The display is simply the screen where these signals are displayed. The
`horizontal and vertical control sections have knobs and buttons that control the horizontal axis
`(which typically represents time) and vertical axis (which represents voltage) of the signals on
`the screen display. The trigger controls allow you to tell the oscilloscope under what conditions
`you want the timebase to start an acquisition.
`
`An example of what the back panel of an oscilloscope looks like is seen in Figure 9.
`
`As you can see, many oscilloscopes have the connectivity features found on personal
`computers. Examples include CD-ROM drives, CD-RW drives, DVD-RW drives, USB ports,
`serial ports, and external monitor, mouse, and keyboard inputs.
`
`Figure 9. Rear panel on the Keysight Infiniium 9000 Series oscilloscope.
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`09 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`What Is an Oscilloscope and Why Do You Need One? (Continued)
`
`An oscilloscope’s purpose
`An oscilloscope is a measurement and testing instrument used to display a certain variable as
`a function of another. For example, it can plot on its display a graph of voltage (y-axis) versus
`time (x-axis). Figure 10 shows an example of such a plot. This is useful if you want to test a
`certain electronic component to see if it is behaving properly. If you know what the waveform
`of the signal should be after exiting the component, you can use an oscilloscope to see if
`the component is indeed outputting the correct signal. Notice also that the x and y-axes are
`broken into divisions by a graticule. The graticule enables you to make measurements by visual
`estimation, although with modern oscilloscopes, most of these measurements can be made
`automatically and more accurately by the oscilloscope itself.
`
`An oscilloscope can also do more than plot voltage versus time. An oscilloscope has multiple
`inputs, called channels, and each one of these acts independently. Therefore, you could
`connect channel 1 to a certain device and channel 2 to another. The oscilloscope could then
`plot the voltage measured by channel 1 versus the voltage measured by channel 2. This mode
`is called the XY-mode of an oscilloscope. It is useful when graphing I-V plots or Lissajous
`patterns where the shape of these patterns tells you the phase difference and the frequency
`ratio between the two signals. Figure 11 shows examples of Lissajous patterns and the phase
`difference/frequency ratio they represent.
`
`Figure 10. An oscilloscope’s voltage versus time display of a square wave.
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`10 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`What Is an Oscilloscope and Why Do You Need One? (Continued)
`
`180 degrees; 1:1 ratio
`
`90 degrees; 1:1 ratio
`
`30 degrees; 1:3 ratio
`
`90 degrees; 1:2 ratio
`
`Figure 11. Lissajous patterns.
`
`Types of oscilloscopes
`Analog oscilloscopes
`
`The first oscilloscopes were analog oscilloscopes, which use cathode-ray tubes to display a
`waveform. Photoluminescent phosphor on the screen illuminates when an electron hits it, and
`as successive bits of phosphor light up, you can see a representation of the signal. A trigger is
`needed to make the displayed waveform look stable. When one whole trace of the display is
`completed, the oscilloscope waits until a specific event occurs (for example, a rising edge that
`crosses a certain voltage) and then starts the trace again. An untriggered display is unusable
`because the waveform is not shown as a stable waveform on the display (this is true for DSO
`and MSO oscilloscopes, which will be discussed below, as well.)
`
`Analog oscilloscopes are useful because the illuminated phosphor does not disappear
`immediately. You can see several traces of the oscilloscope overlapping each other, which
`allows you to see glitches or irregularities in the signal. Since the display of the waveform
`occurs when an electron strikes the screen, the intensity of the displayed signal correlates to
`the intensity of the actual signal. This makes the display act as a three-dimensional plot (in
`other words, x-axis is time, y-axis is voltage, and z-axis is intensity).
`
`The downside of an analog oscilloscope is that it cannot “freeze” the display and keep the
`waveform for an extended period of time. Once the phosphorus substance deluminates,
`that part of the signal is lost. Also, you cannot perform measurements on the waveform
`automatically. Instead you have to make measurements usually using the grid on the display.
`Analog oscilloscopes are also very limited in the types of signals they can display because there
`is an upper limit to how fast the horizontal and vertical sweeping of the electron beam can
`occur. While analog oscilloscopes are still used by many people today, they are not sold very
`often. Instead, digital oscilloscopes are the modern tool of choice.
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`11 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`What Is an Oscilloscope and Why Do You Need One? (Continued)
`
`Digital storage oscilloscopes (DSOs)
`
`Digital storage oscilloscopes (often referred to as DSOs) were invented to remedy many of the
`negative aspects of analog oscilloscopes. DSOs input a signal and then digitize it through the
`use of an analog-to-digital converter. Figure 12 shows an example of one DSO architecture
`used by Keysight Technologies, Inc. digital oscilloscopes.
`
`The attenuator scales the waveform. The vertical amplifier provides additional scaling while
`passing the waveform to the analog-to-digital converter (ADC). The ADC samples and digitizes
`the incoming signal. It then stores this data in memory. The trigger looks for trigger events
`while the time-base adjusts the time display for the oscilloscope. The microprocessor system
`performs any additional postprocessing you have specified before the signal is finally displayed
`on the oscilloscope.
`
`Having the data in digital form enables the oscilloscope to perform a variety of measurements
`on the waveform. Signals can also be stored indefinitely in memory. The data can be printed or
`transferred to a computer via a flash drive, LAN, USB, or DVD-RW. In fact, software now allows
`you to control and monitor your oscilloscope from a computer using a virtual front panel.
`
`Channel
`memory
`
`Channel
`input
`
`Attenuator
`
`Vertical
`amplifier
`
`ADC
`
`MegaZoom
`
`Micro-
`processor
`
`Display
`
`Trigger
`
`Time-base
`
`Figure 12. Digitizing oscilloscope architecture.
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`12 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`What Is an Oscilloscope and Why Do You Need One? (Continued)
`
`Mixed signal oscilloscopes (MSOs)
`
`In a DSO, the input signal is analog and the digital-to-analog converter digitizes it. However,
`as digital electronic technology expanded, it became increasingly necessary to monitor analog
`and digital signals simultaneously. As a result, oscilloscope vendors began producing mixed
`signal oscilloscopes that can trigger on and display both analog and digital signals. Typically
`there are a small number of analog channels (2 or 4) and a larger number of digital channels (8
`or 16, see Figure 13).
`
`Mixed signal oscilloscopes have the advantage of being able to trigger on a combination of
`analog and digital signals and display them all, correlated on the same time base.
`
`8 digital channels
`
`4 analog channels
`
`Figure 13. Front panel inputs for the four analog channels and eight or sixteen digital channels on a
`mixed-signal oscilloscope.
`
`Portable/handheld oscilloscopes
`
`As its name implies, a portable oscilloscope is one that is small enough to carry around. If you
`need to move your oscilloscope around to many locations or from bench to bench in your lab,
`then a portable oscilloscope may be perfect for you. Figure 14 shows an example of a portable
`instrument, the Keysight InfiniiVision X-Series oscilloscope.
`
`The advantages of portable oscilloscopes are that they are lightweight and portable, they
`turn on and off quickly, and they are easy to use. They tend to not have as much performance
`power as larger oscilloscopes, but scopes like the Keysight InfiniiVision 1000, 2000, and 3000T
`X-Series are changing that. These oscilloscopes offer all the portability and ease typically
`found in portable oscilloscopes, but are also powerful enough to handle most of today’s
`debugging needs up to 6 GHz bandwidth.
`
`Figure 14. Keysight InfiniiVision 2000 X-Series portable oscilloscope.
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`13 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`What Is an Oscilloscope and Why Do You Need One? (Continued)
`
`Types of oscilloscopes
`Economy oscilloscopes
`
`Economy oscilloscopes are reasonably priced, but they do not have as much performance
`capability as high-performance oscilloscopes. These oscilloscopes are typically found in
`university laboratories. The main advantage of these oscilloscopes is their low price. For a
`relatively modest amount of money, you get a very useful oscilloscope.
`
`High-performance oscilloscopes
`
`High-performance oscilloscopes provide the best performance capabilities available. They are
`used by people who require high bandwidth, fast sampling and update rates, large memory
`depth, and a vast array of measurement capabilities. Figure 15 shows an example of a high-
`performance oscilloscope, the Keysight Infiniium 90000A Series oscilloscope.
`
`The main advantages of a high-performance oscilloscope are that the scope enables you to
`properly analyze a wide range of signals, and provides many applications and tools that make
`analyzing current technology simpler and faster. The main disadvantages of high-performance
`oscilloscopes are their price and size.
`
`Where oscilloscopes are used
`
`If a company is testing or using electronic signals, it is highly likely they have an oscilloscope.
`For this reason, oscilloscopes are prevalent in a wide variety of fields:
`
` – Automotive technicians use oscilloscopes to diagnose electrical problems in cars.
` – University labs use oscilloscopes to teach students about electronics.
` – Research groups all over the world have oscilloscopes at their disposal.
` – Cell phone manufacturers use oscilloscopes to test the integrity of their signals.
` – The military and aviation industries use oscilloscopes to test radar communication
`systems.
` – R&D engineers use oscilloscopes to test and design new technologies.
` – Oscilloscopes are also used for compliance testing. Examples include USB and HDMI where
`the output must meet certain standards.
`
`This is just a small subset of the possible uses of an oscilloscope. It truly is a versatile and
`powerful instrument.
`
`Figure 15. Keysight Infiniium 90000A Series oscilloscope.
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`14 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`Basic Oscilloscope Controls and Measurements
`
`Basic front-panel controls
`Typically, you operate an oscilloscope using the knobs and buttons on the front panel. In
`addition to controls found of the front panel, many high-end oscilloscopes now come equipped
`with operating systems, and as a result, they behave like computers. You can hook up a mouse
`and keyboard to the oscilloscope and use the mouse to adjust the controls through drop down
`menus and buttons on the display as well. In addition, some oscilloscopes have touch screens
`so you can use a stylus or fingertip to access the menus.
`
`Before you begin . . .
`
`When you first sit down at your oscilloscope, check that the input channel you are using is
`turned on. Then press [Default Settings] if there is one. This will return the oscilloscope to its
`original default state. Then press [Autoscale] if there is one. This will automatically set the
`vertical and horizontal scale such that your waveform can be nicely viewed on the display.
`Use this as a starting point and then make needed adjustments. If you ever lose track of your
`waveform or you are having a hard time displaying it, repeat these steps. Most oscilloscope
`front panels contain at least four main sections: vertical and horizontal controls, triggering
`controls, and input controls.
`
`Vertical controls
`
`Vertical controls on an oscilloscope typically are grouped in a section marked Vertical. These
`controls allow you to adjust the vertical aspects of the display. For example, there will be a
`control that designates the number of volts per division (scale) on the y-axis of the display
`grid. You can zoom in on a waveform by decreasing the volts per division or you can zoom
`out by increasing this quantity. There also is a control for the vertical offset of the waveform.
`This control simply translates the entire waveform up or down on the display. You can see the
`vertical control section for a Keysight InfiniiVision 2000 X-Series oscilloscope in Figure 16.
`
`Horizontal controls
`
`An oscilloscope's horizontal controls typically are grouped in a front-panel section marked
`Horizontal. These controls enable you to make adjustments to the horizontal scale of the
`display. There will be a control that designates the time per division on the x-axis. Again,
`decreasing the time per division enables you to zoom in on a narrower range of time. There
`will also be a control for the horizontal delay (offset). This control enables you to scan through
`a range of time. You can see the horizontal control section for the Keysight InfiniiVision 2000
`X-Series oscilloscope in Figure 17.
`
`Turns channel 1 on
`
`Adjusts the vertical
`scaling for channel 4
`
`Adjusts the horizontal scaling
`
`Horizontally positions
`the waveform
`
`Vertically positions the waveform on channel 2
`
`Figure 16. Front panel vertical control section on a Keysight InfiniiVision
`2000 X-Series oscilloscope.
`
`Figure 17. Front panel horizontal control section on a Keysight
`InfiniiVision 2000 X-Series oscilloscope.
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`15 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`Basic Oscilloscope Controls and Measurements (Continued)
`
`Trigger controls
`
`As we mentioned earlier, triggering on your signal helps provide a stable, usable display
`and allows you to synchronize the scope’s acquisition on the part of the waveform you are
`interested in viewing. The trigger controls let you pick your vertical trigger level (for example,
`the voltage at which you want your oscilloscope to trigger) and choose between various
`triggering capabilities. Examples of common triggering types include:
`
`Edge triggering
`
`Edge triggering is the most popular triggering mode. The trigger occurs when the voltage
`surpasses some set threshold value. You can choose between triggering on a rising or a falling
`edge. Figure 18 shows a graphical representation of triggering on a rising edge.
`
`Glitch triggering
`
`Glitch triggering mode enables you to trigger on an event or pulse whose width is greater than
`or less than some specified length of time. This capability is very useful for finding random
`glitches or errors. If these glitches do not occur very often, it may be very difficult to see them.
`However, glitch triggering allows you to catch many of these errors. Figure 19 shows a glitch
`caught by a Keysight InfiniiVision 6000 Series oscilloscope.
`
`Trigger voltage
`
`Rising edge triggering
`
`Figure 18. When you trigger on a rising edge, the oscilloscope triggers when the trigger threshold is
`reached.
`
`Figure 19. An infrequent glitch caught on a Keysight InfiniiVision 6000 Series oscilloscope.
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`16 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`Basic Oscilloscope Controls and Measurements (Continued)
`
`Pulse-width triggering
`Pulse width triggering is similar to glitch triggering when you are looking for specific pulse
`widths. However, it is more general in that you can trigger on pulses of any specified width and
`you can choose the polarity (negative or positive) of the pulses you want to trigger. You can
`also set the horizontal position of the trigger. This allows you to see what occurred pre-trigger
`or post-trigger. For instance, you can execute a glitch trigger, find the error, and then look at
`the signal pre-trigger to see what caused the glitch. If you have the horizontal delay set to zero,
`your trigger event will be placed in the middle of the screen horizontally. Events that occur right
`before the trigger will be to the left of the screen and events that occur directly after the trigger
`will be to the right of the screen. You also can set the coupling of the trigger and set the input
`source you want to trigger on. You do not always have to trigger on your signal, but can instead
`trigger a related signal. Figure 20 shows the trigger control section of an oscilloscope’s front
`panel.
`
`Input controls
`There are typically two or four analog channels on an oscilloscope. They will be numbered and
`they will also usually have a button associated with each particular channel that enables you to
`turn them on or off. There may also be a selection that allows you to specify AC or DC coupling.
`If DC coupling is selected, the entire signal will be input. On the other hand, AC coupling blocks
`the DC component and centers the waveform about 0 volts (ground). In addition, you can
`specify the probe impedance for each channel through a selection button. The input controls
`also let you choose the type of sampling. There are two basic ways to sample the signal:
`
`Real-time sampling
`
` Real-time sampling samples the waveform often enough that it captures a complete image
`of the waveform with each acquisition. Some of today’s higher performance oscilloscopes can
`capture up to 32-GHz bandwidth signals in a single shot utilizing real-time sampling
`
`Equivalent-time sampling
`
`Equivalent time sampling builds up the waveform over several acquisitions. It samples part of
`the signal on the first acquisition, then another part on the second acquisition, and so on. It
`then laces all this information together to recreate the waveform. Equivalent time sampling is
`useful for high-frequency signals that are too fast for real-time sampling (> 32 GHz).
`
`Adjusts the trigger level
`
`These keys
`allow you to
`select the
`trigger mode
`
`Figure 20. Front panel trigger control section on a Keysight InfiniiVision 2000 X-Series oscilloscope.
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`17 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`Basic Oscilloscope Controls and Measurements (Continued)
`
`Softkeys
`Softkeys are found on oscilloscopes that do not have Windows-based operating systems (refer
`to Figure 8 for a picture of softkeys). These softkeys allow you to navigate the menu system
`on the oscilloscope’s display. Figure 21 shows what a popup menu looks like when a softkey
`is pressed. The specific menu shown in the figure is for selecting the trigger mode. You can
`continually press the softkey to cycle through the choices, or there may be a knob on the front
`panel that allows you to scroll to your selection.
`
`Figure 21. The Trigger Type menu appears when you push the softkey underneath the trigger menu.
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`18 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`Basic Oscilloscope Controls and Measurements (Continued)
`
`Basic measurements
`Digital oscilloscopes allow you to perform a wide range of measurements on your waveform.
`The complexity and range of measurements available depends on the feature set of your
`oscilloscope. Figure 22 shows the blank display of a Keysight 8000 Series oscilloscope. Notice
`the measurement buttons/icons lined up on the far-left side of the screen. Using a mouse, you
`can drag these icons over to a waveform and the measurement will be computed. They are also
`convenient because the icons give you an indication of what the measurement computes.
`
`Basic measurements found on many oscilloscopes include:
`
`Peak-to-peak voltage
`
`This measurement calculates the voltage difference between the low voltage and high voltage
`of a cycle on your waveform.
`
`Figure 22. The blank display of a Keysight oscilloscope.
`
`Figure 24. An example of risetime (0 to 100% of peak-to-peak voltage is
`shown instead of the usual 10 to 90%).
`
`Figure 23. Peak-to-peak voltage.
`
`Tektronix, Exhibit 2022
`Rohde v. Tektronix, IPR2018-00643
`
`

`

`19 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`Basic Oscilloscope Controls and Measurements (Continued)
`
`RMS voltage
`
`This measurement calculates the RMS voltage of your waveform. This quantity can then be
`used to compute the power.
`
`Risetime
`
`This measurement calculates the amount of time it takes for the signal to go from a low voltage
`to a high voltage. It is usually calculated by computing the time it takes to go from 10% to 90%
`of the peak-to-peak voltage.
`
`Pulse width
`
`A positive pulse width measurement computes the width of a pulse by calculating the time it
`takes for the wave to go from 50% of the peak-to-peak voltage to the maximum voltage and
`then back to the 50% mark. A negative pulse width measurement computes the width of a
`pulse by calculating the time it takes for the wave to go from 50% of the peak-to-peak voltage
`to the minimum voltage and then back to the 50% mark.
`
`Period
`
`This measurement calculates the period of the waveform.
`
`Frequency
`
`This measurement calculates the frequency of your waveform.
`
`This list is intended to give you an idea of the kinds of measurements available on many
`oscilloscopes. However, most oscilloscopes can perform many more measurements.
`
`Basic mathematical functions
`In addition to the measurements discussed above, there are many mathematical operations you
`can perform on your waveforms. Examples include:
`
`Fourier transform
`
`This math function allows you to see the frequencies that compose your signal.
`
`Absolute value
`
`This math function shows the absolute value (in terms of voltage) of your waveform.
`
`Integration
`
`This math function computes the integral of your waveform.
`
`Addition or subtraction
`
`These math functions enable you to add or subtract multiple waveforms and display the
`resulting signal.
`
`Again, this is a small subset of the possible measurements and mathematical functions
`available on an oscilloscope.
`
`Tektronix, Exhibit 2022
`Rohde v. Tektronix, IPR2018-00643
`
`

`

`20 | Keysight | Basic Oscilloscope Fundamentals - Application Note
`
`Important Oscilloscope Performance Properties
`
`Many oscilloscope properties dramatically affect the instrument’s performance and, in turn,
`your ability to accurately test devices. This section covers the most fundamental of these
`properties. It also will familiarize you with oscilloscope terminology and describe how to make
`an informed decision about which oscilloscope will best suit your needs.
`
`Bandwidth
`Bandwidth is the single most importan