9 Factors to Consider When Choosing an Oscilloscope

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If you’re involved in electronics, you’ll probably have an oscilloscope on your bench. As electronics become more complex almost daily, sooner or later a new oscilloscope will be in order. How to choose the right one for your applications?

Factors to consider:

Remember that the bandwidth specification of an oscilloscope is the frequency of the “-3 dB point” of a sine-wave signal of a particular amplitude, e.g. 1 Vpp. As the frequency of your sinewave goes up (while keeping the amplitude constant), the measured amplitude goes down. The frequency at which this amplitude is -3 dB lower, is the instrument’s bandwidth. This means that an oscilloscope of 100MHz would measure a 1Vpp sinewave of 100MHz at only (approx.) 0.7Vpp. That is an error of about 30%! In order to measure more correctly, use this rule of thumb: BW/3 equals about 5% error; BW/5 equals about 3% error. In other words: if the highest frequency you want to measure is 100 MHz, choose an oscilloscope of at least 300MHz, a better bet would be 500MHz. Unfortunately, this has the most influence on the price…

Understand that today’s signals are no longer pure sine waves, but most of the time square waves. These are built by “adding” the odd harmonics of the fundamental sine wave together. So a 10 MHz square wave is “built” by adding a 10MHz sine wave + a 30MHz sine wave + a 50MHz sine wave and so on. Rule of thumb: get a scope that has a bandwidth of at least the 9th harmonic. So if you’re going for square waves, it’s better to get a scope with a bandwidth of at least 10x the frequency of your square wave. For 100MHz square waves, get a 1GHz scope… and a bigger budget…

Consider rise (fall) time. Square waves have steep rise and fall times. There’s an easy rule of thumb to get to know what bandwidth your scope needs to be if these times are important to you. For oscilloscopes with bandwidths below 2.5GHz, calculate the steepest rise (fall) time it can measure as 0.35/BW. So an oscilloscope of 100MHz can measure rise times up to 3.5ns. For oscilloscopes above 2.5GHz up to about 8GHz, use 0.40/BW, and for scopes above 8GHz use 0.42/BW. Is your risetime the starting point? Use the inverse: if you need to measure rise times of 100ps, you’ll need a scope of at least 0.4/100ps = 4 GHz.

Choose your sample speed. Today’s oscilloscopes are almost all digital. The above steps involved the analog part of the instrument, before it gets to the A/D converters to get “digitized”. Here the bandwidth-to-rise time calculation can help you out: an oscilloscope of 500MHz has a calculated rise time of 700ps. To reconstruct this, you need at least 2 sample points on this edge, so at least a sample each 350ps, or 2.8Gsa/s (gigasamples per second). Scopes don’t come in this flavor, so choose a model with a faster sampling speed, e.g. 5Gsa/s (resulting in 200ps “time resolution”).

Decide on the number of channels. This is easy: most scopes come with 2ch or 4ch configurations, so you can choose what you need. Fortunately prices don’t double from 2ch to 4ch, but it does have a big impact on the price of the instrument. High-end scopes (>=1GHz) have always 4ch.

Calculate how much memory you’ll need. Depending on how much of your signal you want to see in a “single shot acquisition”, get your math right: at 5Gsa/s, you have a sample each 200ps. A scope with a memory of 10.000 sample points, can store 2µs of your signal. A scope with 100M samples (they do exist!) can store 20 seconds! Looking at repetitive signals or “eye-diagrams”, memory is less important.

Think about repetition rate. A digital oscilloscope uses a lot of time calculating. Between the moment of triggering (see next step), having the captured signal on the display, and capturing the next triggered event, most digital scopes “consume” several milliseconds. This results in only a few “photos” of your signal each second (waveforms per second), typically about 100-500. One vendor solved this problem with so called “Digital Phosphor” (from about 4.000 wfms/s to >400.000 wfms/s for the top models), others followed with similar-like technologies (but not always sustained/continuous, rather in bursts). This repetition rate is important because those rare errors and faults in your signal might occur just then when the scope is not acquiring, but busy calculating the last taken acquisition. The higher the repetition rate (wfms/s rate), the higher your chances are of capturing that rare event.

Check what kind of errors you expect to be looking for. All digital scopes have some sort of intelligent triggers on board, meaning you can trigger on more than just the rising or falling edge of your signal. If your repetition rate is high enough, you’ve probably seen that rare glitch every other second. Then it’s nice to have a Glitch trigger.

Think about resolution of LCD display. Small screens with poor resolution can make your life miserable if you cannot see results easily. Buy the largest screen with the best definition your budget will allow.

Some Final Tips

  • Triggering, repetition rate and memory: once you found the rare event with a high wfms/s rate, having the right trigger available is more important than repetition rate, as your scope will trigger only on the (rare) event, which occurs… right: rarely. So you don’t need high rep-rate anymore. Memory can become more important, as to be able to analyze what happened before or after the event.
  • Remember: garbage in is garbage out, so get the bandwidth and rise time issue sorted out first!

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor that specializes in providing unique Electronic Test & Measurement tools for design engineers, test engineers and production engineers. You can visit our website at http://www.northtreeassociates.com

NorthTree Associates Announces Micsig Sales Promotion On TO202 and TO202A tBook Tablet Oscilloscopes

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A new Micsig sales promotion is underway at NorthTree Associates. The Micsig TO202 and TO202A  tBook Tablet Oscilloscope have been put on sale at special prices.

The Micsig TO 202 tBook Tablet Oscilloscope has 2 channels, a 200MHz bandwidth, and a 1GSs sampling rate is now priced at $669.00. CLICK HERE NOW to order and see complete specifications.

In addition, the MicsigTO202A tBook Tablet Oscilloscope has 2 channels, 200MHz bandwidth, and a 2GSs sampling rate is now priced at $769.00. CLICK HERE NOW to order and see complete specifications.

As the tBook Tablet Oscilloscope innovator, Micsig has achieved various worldwide patent rights, software copyright for their touch screen tBook Tablet Oscilloscope. Features include: a multi-touch screen, 100MHz to 200MHz bandwidth, 2 or 4 channels, real time sampling rates of 1GS/s to 2GS/s, compact design, high memory depths, and excellent function features.

The affordably priced Micsig handheld oscilloscopes offer bandwidths ranging from 70MHz up to 200MHz, two channels and 1GS/s sampling rate, making them deal for both laboratory testing and field service applications across a wide range of industry sectors.

High performance features offered by Micsig oscilloscopes include isolated inputs for safely carrying out floating measurements, up to 190,000 wfms/s refresh rate, support for serial bus protocol trigger and decode (1553B/429/UART/232/485/LIN/CAN/SPI/12C) in both graphic and text modes, and multi-function operation including digital oscilloscope, digital multimeter and recorder.

In oscilloscope mode, the units offer a wide range of trigger types, 31 automatic measurements, and maths functions including FFT. Isolated input versions offer up to 1000V CAT II 600V CAT III maximum channel floating voltage.

Designed for user-friendly operation with Micsig’s touch screen technology, the oscilloscope offers three operation modes – moving the waveform, zooming in and out, and menu option selection – with the large 5.7 inch TFT LCD screen providing users with a sharp 640 x 480 high resolution display. A user selectable indoor (black background) or outdoor (white background) display mode makes the models particularly useful in field service applications.

The Li-ion batteries provide users with up to 6 hours of continuous operation, while the USB host and slave interface allows users to easily download captured waveforms as well as connect the oscilloscopes to a PC.

NorthTree Associates based in Cologne, MN provides unique Electronic Test & Measurement tools for increasing productivity. You can reach NorthTree Associates at sales@northtreeassociates.com

LabNation SmartScope Open Source USB Oscilloscope

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LabNation has announced the launch of an open source USB oscilloscope dubbed SmartScope. Using a Kickstarter campaign that started in 2014, the project raised 645% of its funding goal within 30 days. Believed to be the world’s first test equipment designed to run on multiple operating systems and platforms such as smartphones, tablets and PCs, the SmartScope is powered directly from the host’s USB interface.

The SmartScope combines the multiple functions of an oscilloscope including a logic analyzer and a waveform generator in a case measuring just 110.0 x 64.0 x 24.2 mm, weighing only 158 grams. The software provides the user interface and functionality, and can be downloaded from the SmartScope website. It is available for Android (Google Play Store or LabNation website), Apple Mac OS X, Apple iOS (jailbroken), Microsoft Windows 7, 8 and 10, and Ubuntu and Debian Linux distributions.

The oscilloscope provides two analog channels with a sample rate up to 100 MS/s and provides a -3dB bandwidth of 30 MHz, input signal range of ±35 V with a 1 MΩ / 1pF impedance, an 8-bit precision and a maximal resolution of 2.5mV.

The LabNation SmartScope oscilloscope software provides a comprehensive set of on-screen functions, either by touch, mouse or keyboard controls, for voltage scaling, time-based scaling, panning, input coupling, triggering and simple voltage measurements. The logic analyzer offers eight input channels with a user selectable logic level of 3.3 or 5 VDC. The application includes a number of standard protocol decoders such as I2C and SPI in addition to allowing the creation of custom decoders. The single channel waveform generator creates arbitrary waveforms with a data rate up to 50 MS/s and an output level from 0 to 3.3 V.

A digital output generator provides four channels, up to a rate of 100 MS/s at either 3.3 or 5 V. The LabNation SmartScope is ideal for the growing numbers of makers using small board computers such as Raspberry Pi and Arduino to diagnose faults and learn more about how basic electronics and how their design is functioning. The light compact unit suits a broad variety of electronics engineering, field service, education, and hobbyist applications. The small form-factor unit is supplied complete with a mini ‘B’ USB cable, two analog probes, digital cable and probes.

NorthTree Associates has represented LabNation SmartScope since 2014. Contact us with any questions or comments concerning the LabNation SmartScope or any of the other fine products we sell. www.northtreeassociates.com

Choosing the Right Diagnostic Automotive Oscilloscope for Your Auto Repair Shop

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Searching for Answers: Choosing Your Oscilloscope

Every shop will have different needs and uses for an oscilloscope, so it’s important to identify your facility’s specific needs from the equipment. Here are six steps to cover so your choice is the most correct one.

Step 1: What kind of vehicles are worked on? Take a look at the shop’s mix. What kind and type of vehicles are repaired the most? What makes, models and years are seen most often? “The more specific and ‘specialized’ the work that can be provided, the better off the shop will be. Choose the 10 most worked-on vehicles, and figure out the needs for those.

Step 2: Consider what isn’t worked on. Obviously, an oscilloscope should be able to help in bringing in additional business, jobs, revenue and, as is the overall goal – profitability. Will it be a tool that can help in bringing in vehicles in the area that the shop is missing out on? Are there any other shops working on a specific vehicles? If not, can the right oscilloscope help the shop take advantage of this opportunity?

Step 3: Research oscilloscopes. Here’s where shops often get off track or go the easy route. But if the proper approach is used and the correct observance of the shop’s work mix (Steps 1 and 2), then it narrows it down quite a bit. Here are six things to consider:

Coverage. What software does the tool come with? What updates? What vehicles does the software cover? Makes and model years? Because of changes in vehicle design and capabilities, how often is the software updated? It needs to be understood what each software package is capable of diagnosing.

Training/Ease of Use. Most oscilloscopes are “plug & play” aftermarket tools. Higher-end oscilloscopes often come with a steeper learning curve for first-time users. Try to get a feel for how long it will take shop technicians to master the equipment, and what training or support is offered.

Compatibility. Some oscilloscopes are Windows-based PC or laptop-based, and that often means one oscilloscope with powerful software can provide a wide range of coverage.

Technical Support. Got hotline? Some oscilloscope manufacturers provide hotlines of sorts to call for additional information or for support for difficult diagnoses. Understand how each oscilloscope is supported.

Upgrades/Updates. Oscilloscopes are constantly being upgraded and updated. Research the companies you’re considering and see what they offer in terms of upgrades. Not only for the purpose of the software but also for the oscilloscope.

Cost. An obvious point. Do you want a high-end do it all oscilloscope, then get ready to pay significantly. There’s going to be a large discrepancy in price between oscilloscope makers. This is why understanding the work mix of the shop is important to grasp the value of the tool.

Step 4: Analyze the return. There are a lot of ways to try to analyze how valuable a diagnostic oscilloscope is for a shop. One way to analyze the return is to low-ball the return and only compare the cost of the tool (including subscriptions and upgrades) to the amount of profit made on diagnostic charges. This will gave an absolute minimum that can serve to directly pay off the tool.

Step 5: Demo the tools. Be wary of any company that isn’t confident enough in its oscilloscope to let you have it for trial period. What is their return policy? If the oscilloscope doesn’t fit your needs, can you return it NQA? Using the oscilloscope on your own is important in making the right decision.

Step 6: Implement the tools. Although this step must come after you selected and purchased a tool, it will also help to confirm your decision. Don’t just simply buy diagnostic equipment and hand it off to the technician. Create processes and systems for your shop to use it correctly, Seyfer says, and make sure to market your capabilities.

Keep It Simple

Choosing an oscilloscope for the shop can be a difficult task. The most important thing to remember, is to find the best fit for your shop. Get as much information as possible. Speak with other shops, talk with vendors, ask about it in association gatherings, and on message boards—anywhere you can. There’s plenty of information out there about each tool.

In the end, try to make the process as simple as you can.

Should you have any questions, you can contact us directly by filling out the form below.

10 Reasons Why You Need A PC Oscilloscope

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PC Oscilloscopes (PCOs) are rapidly replacing traditional digital storage oscilloscopes (DSOs) as the essential item for your test equipment arsenal. Here are 10 reasons why:

  1. Compact and portable units
  2. Uses your PC monitor to provide a large and detailed color display
  3. Signal storage is limited only by your PC’s storage capability
  4. Captured waveforms and instrument settings can easily be shared with others
  5. New functionality through free software updates
  6. Can be used with desktop or laptop PCs
  7. High-speed USB 3.0 connection (parallel port oscilloscopes are also available)
  8. Hardware and software in one package
  9. Use your PC Oscilloscope for data acquisition
  10. A complete test and measurement lab in one unit

1.  Compact and portable units

By integrating several instruments into one small unit, PC Oscilloscopes (PCOs) are lighter and more portable than traditional test equipment. When used with a laptop computer, you can carry a complete electronics lab in the same bag as your PC.

2.  Uses your PC monitor to provide a large and detailed color display

The display of a traditional oscilloscope is limited by the physical size of the oscilloscope, and may only be a single color. With a PC Oscilloscope your computer controls the display, so not only do you get a full color display, but the display can be the size of your monitor, projector or plasma display.

3.  Signal storage is limited only by your PC’s storage capability

PC Oscilloscopes store the signals that you are measuring directly on your PC. With the power of today’s modern PCs this gives you vast storage capabilities. Along with allowing you to record lengthy signals this also lets you save signals for reviewing at a later date.

4.  Captured waveforms and instrument settings can easily be shared with others

Need to show your customer or colleague the signal you have captured? Just save the waveform and email them a copy. They don’t have a copy of the oscilloscope software? No problem – just export it as text, an image or in a binary format for use with third-party software. (If they want to set up their equipment to run the same test, simply send them the oscilloscope settings too.)

5.  New functionality through free software updates

If you’re lucky you can return a traditional DSO to the supplier for a firmware upgrade and maybe get improved functionality. With a PC-based oscilloscope new features and improved functionality can be added at any time with a simple software update. Free software updates means that a PC Oscilloscope is one of the few things that can actually become more powerful and useful with age.

6.  Can be used with desktop or laptop PCs

PC Oscilloscopes are external devices that are connected to your PC using the ubiquitous Universal Serial Bus (USB). Virtually every laptop or desktop PC sold comes with multiple USB ports so there’s no problem using your PC Oscilloscope with either a desktop or a laptop PC.

7.  High-speed USB 3.0 connection

USB 3.0 can transfer data at speeds of up to 1 GS/s. Using powerful PC Oscilloscope software it give you incredible performance with fast screen updates and the ability to stream data.

8.  Hardware and software in one package

Choose PC Oscilloscopes that come complete with the hardware and software in one package.

9.  Use your PC Oscilloscope for data acquisition

Using the sw, you can transform your PC Oscilloscope into a data logger that can log data over extended periods of time.

10.  A complete test and measurement lab in one unit

When you buy a PC-based oscilloscope make sure you don’t just get an oscilloscope: make sure you also get a spectrum analyzer, meter and data logger rolled into your PC-Oscilloscope choice. Some models even include a built–in signal generator or arbitrary waveform generator. So with a PC Oscilloscope you really do get a complete test and measurement lab in one cost–effective unit.

NorthTree Associates is a distributor and supplier of Electronic Test & Measurement Equipment. Companies represented include ITIC USB 2.0 Protocol Analyzers, LabNation SmartScopes, Micsig Oscilloscopes, Oscium iOS Test Tools, OWON Oscilloscopes.

5 Features To Consider When Choosing A Digital Oscilloscope

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For anyone designing, manufacturing, or repairing electronic equipment, a digital storage oscilloscope is a must-have tool. It lets you see high-speed repetitive or single-shot signals across multiple channels to capture elusive glitches or transient events. An oscilloscope is equally as useful a tool for qualifying elements of a new design as it is for isolating problem components in an existing system under repair.
When it comes to evaluating oscilloscopes, many engineers focus on one specification: bandwidth. The assumption is generally that the faster oscilloscope is the better oscilloscope. And while bandwidth is an important thing to consider, it falls well short of telling the whole story or in ensuring that the oscilloscope you’re considering will truly meet your needs. With that in mind, here are five other things you’ll want to consider when choosing your next oscilloscope.

1. Rise time — Accurate rise-time measurements are key to making accurate measurements in the time domain. Many logic families have faster rise times (edge speeds) than their clock rates suggest. A processor with a 20 MHz clock may well have signals with rise times similar to those of an 800 MHz processor. Rise times are important for studying square waves and pulses. Square waves are standard for testing amplifier distortion and timing signals for TVs and computers. Pulses may represent glitches or information bits — too slow a rise time for the circuit being tested could shift the pulse in time and give a wrong value.

2. Fast sample rate — The sample rate of an oscilloscope is similar to the frame rate of a movie camera. It determines how much waveform detail the scope can capture. To capture glitches you need speed. A signal must be sampled at least twice as fast as its highest frequency component to accurately reconstruct it and avoid aliasing (showing artifacts that are not actually there). This is however an absolute minimum. What’s more, it applies only to sine waves and assumes a continuous signal. Glitches are by definition not continuous, and sampling at only twice the rate of the highest frequency component is usually not enough. A high sample rate increases resolution, ensuring that you’ll see intermittent events. As a rule of thumb, look for a sample rate of at least 5x your circuit’s highest frequency component.

3. Versatile triggering — All oscilloscopes provide edge triggering, and most offer pulse width triggering. But more advanced triggering capabilities can save you time and shorten the time to answer when working with more challenging signals. The wider the range of trigger options available, the more versatile the scope. Some of the triggers available include A & B sequence triggering; video triggering on line/frame/HD signals, etc.; logic triggers such as slew rate, glitch, pulse width, time-out, runt, setup-and-hold; and communications triggers for serial and parallel buses.

4. Powerful waveform navigation and analysis — Searching for specific waveform errors can be like searching for a needle in a haystack. Tools that automate the process can be a big time saver. For instance, oscilloscopes with record lengths in the millions of points can show thousands of screens worth of signal activity, essential for examining complex waveforms. Capabilities such as search and mark speed up the process by letting you search through the entire acquisition and automatically mark every occurrence of an event you specified. Other capabilities include zoom and pan, play and pause, and advanced search.

5. Matching probes — Precision measurements start at the probe tip. The probe’s bandwidth must match that of the oscilloscope, and must not overload the Device Under Test (DUT). Probes actually become a part of the circuit, introducing resistive, capacitive and inductive loading that alters the measurement. It’s important to have a range of probes available. To start with, select passive probes that have high bandwidth and low loading. Active ground-referenced probes offer one to four GHz bandwidth while active differential probes support 20 GHz or more. Adding a current probe enables the scope to calculate instantaneous power, true power, apparent power and phase. High voltage probes measure to 40kV peak. Specialty probes include logic, optical and environmental types.

Cost of ownership
Any scope you choose will need to fit within the constraints of a capital acquisition budget. While cost of ownership isn’t a feature per-se, it’s an important consideration.  This means you should compare support options to see to whether they add value to your purchase or can help extend the scope’s useful life. On-site education and training, as well as design, system integration, project management, and other professional services can help maximize productivity and ensure reliable measurements. Support packages such as these, along with options like extended warranty can save money in the long term.

Contact us with your questions or if you would like to visit our online store to shop for digital oscilloscopes – visit http://www.northtreeassociates.com / sales@northtreeassociates.com

NorthTree Associates Introduces OWON XDS Series Multi-Function Oscilloscopes

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The XDS series of oscilloscopes is the latest product release from OWON. With 12‐bit resolution, the XDS series offers the best solution for those who need to measure small signals or be able to read details from a large signal. Highly suitable for Medical, Automotive, Power Supply, and more.

In addition to having a 12‐bit resolution, the OWON XDS series of oscilloscopes are equipped with advanced technology and functions such as advanced trigger and decoding functions, Wi‐Fi and App support along with a capacitance touch screen.

OWON XDS series oscilloscopes come with the OWON 3rd generation technology platform ‐ Xvisual, which advances the performance of the XDS series oscilloscopes over other oscilloscopes available. The new Xvisual platform consists of 3 parts: Low Base Noise, 40M Record Length, 75,000 wfms/s Refresh Rate. One of the main benefits of Xvisual is ease at which the measurement of small signals can be read, and the ability to fully restore the true status of signals.

The XDS series oscilloscope software, provides advanced trigger and protocol decoding functions to help engineers analyze bus protocols and quick positioning. The embedded Wi‐Fi module ensures computers and cell phones can share the display screen to view and control the oscilloscope. Users can also check and save waveform data via App. By saving data via the App, data can be shared between other users.

The optional capacitance touch screen has been designed to look and act similar to a Smartphone – thus being intuitive and easy to start using right out of the box.

Additionally, the OWON XDS is complete mobile test station. It has incorporated the ultra‐thin design of the OWON SDS series oscilloscope, and has a battery option for portable use in the field. Besides the oscilloscope function, the OWON XDS also has function modules such as: a 25 MHz/50MHz single/dual channel(s) arbitrary waveform generator, a digital multimeter and a high precision data logger.

Established in 2004, NorthTree Associates (Cologne, MN) is a North American distributor for OWON oscilloscopes, waveform generators, and programmable power supplies. NorthTree Associates provides unique Electronic Test & Measurement tools for design engineers, test engineers and production engineers.