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Rohde & Schwarz Achieves 4.5 M Acquisition/sec Update Rate with 12-bit Oscilloscope

September 28, 2022 by Jeff Child

Eliminating cost/performance trade offs, Rohde & Schwarz has unveiled an oscilloscope that does 12-bit resolution across all sample speeds and a 4.5 million waveform/sec update rate.

If you rank the essential everyday tools for the average electronics engineer, oscilloscopes are high on their list. Serving those needs, today Rohde & Schwarz (R&S) announced its R&S MXO 4 (4000) series of oscilloscopes that offer a number of high-performance specs, including a real-time update rate of over 4.5 million acquisitions per second.

In this article, we discuss the details of the MXO 4, we explain what its key features mean for users, and we share insights from our interview with Elizabeth McKenna, product manager for value Instruments and Greg McCaskill, product manager for oscilloscopes at R&S.

 

Marriage of Cost and Performance Optimizations

According to McKenna, the new MXO 4 series is intended to bridge the gap between R&S’s cost optimized FPGA-based oscilloscopes and its ASIC-based performance optimized scopes.

 

The Rohde & Schwarz MXO-4 series oscilloscope provides a real-time update rate of over 4.5 million acquisitions per second.

The Rohde & Schwarz MXO-4 series oscilloscope provides a real-time update rate of over 4.5 million acquisitions per second.

 

As McKenna explains, the company’s performance-optimized scopes were able to compete in high-end applications and at high measurement speeds because of its ASIC designs. “This was all possible because of our fast and sophisticated ASICs that were built into the hardware of these oscilloscopes,” she says.

“Now we're bringing this cost optimization and this performance optimization group together with our new MXO 4 series class. The oscilloscope is based on brand-new hardware technology blocks, which includes an ASIC designed specifically for the MXO 4 series,” says McKenna.

To summarize the performance of the new scope, the key features include: 

  • 200 MHz - 1.5 GHz bandwidth
  • Update rate over 4.5 million waveforms per second
  • 18-bit vertical resolution/12-bit ADC architecture
  • Deep memory at 400 Mpoints
  • Spectrum acquisition rate of 45,000 FFT (Fast Fourier Transforms)/s

What’s significant, according to McKenna, is the combination of those high-performance specs at a starting price point of $8,400 (7,600 euros). More information and documentation is available on the MXO 4’s data sheet page

 

Fast Update Rate and Deep Memory

R&S claims a number of firsts for this new scope series. Two of the product’s most significant features are its super fast update rate and its deep memory. According to Greg McCaskill, the MXO 4’s real-time update rate of over 4.5 million acquisitions per second is the industry’s fastest. Basically, that means that engineers can now see more signal detail and infrequent events than with other oscilloscopes. But trigger rearm time is another way to look at it, says McCaskill.

 

"Another way to look at the fast update rate is how it translates to trigger rearm time. For this oscilloscope, we offer the shortest trigger rearm time with less than 21 nanoseconds between trigger events. This makes a huge step forward as far as update rate in a scope class that's widely used for general purpose debugging and lots of different applications."

 

On the left is a scope that captures only 10,000 waveforms per second. The R&S MXO 4 (right) can capture 4.5 million waveforms per second, resulting in much more visibility.

On the left is a scope that captures only 10,000 waveforms per second. The R&S MXO 4 (right) can capture 4.5 million waveforms per second, resulting in much more visibility.

 

What that means is that the scope enables you to see infrequent events. You’re able to have a view into a lot of glitches and be able to capture those faster, and you're more likely to capture them. “You have a higher statistical probability of capturing rare events when you're less blind, so to speak,” says McKenna.

Aside from sample rate, memory depth is another important factor for oscilloscopes. The MXO 4 provides simultaneous standard acquisition memory of 400 Mpts (million points) on all four channels. The company claims that is up to 100 times the standard memory of its leading competitor.

According to McCaskill, the need for deep memory was strongly expressed as a request from engineer customers. “They want lots of memory so they can capture lots of time,” he says. “They might be looking at protocol debugging, maybe low speed serial buses, or they may need to observe some analog channels. At the same time, you have to have a lot of memory to maintain sample rate for maybe a whole second or even hundreds of milliseconds.”

 

12-bits of Capture at All Sample Rates

A key element of the MXO 4 series is its 12-bit analog-to-digital converter (ADC). Implemented using a Texas Instruments ADC device, this gives the scope 16 times the resolution of traditional 8-bit oscilloscopes, says the company.

While 12-bits in an oscilloscope is not new, the fact that the MXO 4 offers 12-bit resolution at all sample rates is significant. “This enables 12-bit resolution without any tradeoffs for more precise measurements,” says McCaskill.

The MXO 4 also features an 18-bit vertical resolution architecture for greater resolution precision. According to the company, scope boasts the “lowest noise and largest offset range (±5V with a 500 μV/div scaling) in its class.”

This means that engineers can view DC and other signals with more precision than with other oscilloscopes. The R&S MXO 4 oscilloscopes are offered in four-channel models with bandwidths of 200 MHz, 350 MHz, 500 MHz, 1 GHz, and 1.5 GHz. 

 

Digital Trigger and RF Measurement

Other significant aspects for the MXO 4 oscilloscope are its digital trigger capability and its RF measurement features. According to R&S, digital triggering was once only available in higher performance oscilloscopes at higher prices. The digital trigger comes standard with all R&S MXO 4 series oscilloscopes, with a trigger sensitivity of 1/10,000 vertical division. This lets engineers isolate hard-to-find small physical layer anomalies in the presence of large signals.

 

The digital trigger feature comes standard with MXO 4 scopes. This lets engineers isolate difficult-to-find glitches inside of large signals.

The digital trigger feature comes standard with MXO 4 scopes. This lets engineers isolate difficult-to-find glitches inside of large signals.

 

Serving the needs of RF measurement, the MXO 4 is what the company claims is the first oscilloscope to perform 45,000 FFTs per second, while comparable oscilloscopes deliver fewer than 10 FFTs per second. This feature lets engineers view more RF signals than other oscilloscopes in its class. The MXO 4 lets you decouple the time domain. Many development engineers need to debug products and test in both the time and frequency domains, says McCaskill.

 

Physical Aspects of the MXO 4 Scope

The R&S MXO 4 series embeds a 13.3-inch full-HD capacitive touchscreen. A VESA mounting and a rackmount kit is included to help engineers integrate the system into their workspace. Upgrades are available, including 16 integrated digital channels with a mixed signal oscilloscope (MSO) option, an integrated dual channel 100 MHz arbitrary generator, and protocol decode and triggering options for a selection of industry standard buses. The R&S MXO 4 series oscilloscopes are now available from Rohde & Schwarz and selected distributors.

While there are still some applications and markets that may need extremely high-end, high-performance, expensive oscilloscopes, there will always be that basic need for a desktop/benchtop scope that an engineer uses everyday. And many engineers end up using their scope for something different every day. Perhaps scope products like the MXO 4 can bring high-performance test and measurement capabilities into this range of everyday engineering.

 

All images courtesy of Rohde & Schwarz