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Signal Wave Explorer now for sale!

Robust Circuit Design Posted on January 5, 2016 by adminJanuary 5, 2016

BIG NEWS! Just in time for the new year, our first product, Signal Wave Explorer (SWE), can now be purchased online from this site. We are giving SWE the introductory price of just $19.99. So click on the Store menu and go shopping!

After your purchase, you can download the trial version of the product. This version is good for 21 unique usage days before you must complete the registration process. See the product documentation for details.

If you want to try SWE before you buy, no problem! Just head over to the Downloads page (accessed from the Downloads menu) and download the trial version now. Also, while you are there, check out the free preview version of Signal Chain Explorer (SCE) — the sister product to SWE.

We have many new features in store for both products during the course of this year, and while we haven’t finalized our sales policies, the plan is to offer good upgrade discounts for existing customers.

Posted in Signal Wave Explorer | Leave a reply

Visualizing Noise in Signal Wave Explorer

Robust Circuit Design Posted on December 3, 2015 by adminDecember 3, 2015

Our new product Signal Wave Explorer will soon be ready for sale. It was a long and unexpected journey developing this product — unexpected because we weren’t quite sure when we started what the program would be capable of, and we kept getting surprised on the things it could do and what we could learn about signal processing.

One of the exciting new features we’ve added is the ability to visualize thermal noise, (well, really, any type of Gaussian “white-noise.”) Here’s a clean, 2 MHz trapezoid signal with no noise, created using the Wave Definition Dialog of Signal Wave Explorer, using a sampling interval of 6.25 nS, for a sampling frequency of 160 MHz, and thus, 80 samples per trapezoid:

Trapezoid wave definition

Notice the group box on the lower left corner. It’s here that you can add noise to the waveform, in terms of Signal to Noise Ratio (SNR). If you specify 48 dB SNR, select the “To end of signal” radio button, and press “Update”, then randomized noise (using Gaussian aka “normal” distribution) is added at a ratio of 251 parts signal to 1 part noise (48 dB) in terms of signal power. You end up with a wave looking something like:

Trapezoid with 48 dB noise
A signal with 48 dB SNR

Here are other examples, using 24 dB, 10 dB, 0 dB, and even -6 dB SNR:

Trapezoid with 24 dB noise
A signal with 24 dB SNR

Trapezoid with 10 dB noise
A signal with 10 dB SNR

Trapezoid with 0 dB noise
A signal with 0 dB SNR

Trapezoid with -6 dB noise
A signal with -6 dB SNR

With this last example, you end up with a signal that doesn’t look anything like a trapezoid. But one of the cool things about signal processing is that if you know some properties of the signal, you can recover some semblance of it.

For example, suppose you are expecting a 2 MHz signal. You can add a 2 MHz “bandpass” filter in the form of a damped LRC filter, (damped using a resistor to prevent too much ringing, so admittedly it’s not much of a bandpass) and recover at least some aspects of the signal. Here’s an analog filter we quickly concocted in Signal Wave Explorer using the System Definition Dialog:

A 2 MHz LRC filter  A filter to help isolate 2 MHz frequencies in the signal

Note the Bode chart, which shows the sampling range of our system in a light blue overlay. We can see that the peak is covered. Having this visual ability helps greatly in understanding what the sampling will do with our signal.

With Signal Wave Explorer, you can run a sampled simulation of our system, using multiple pulses of our signal, and see what you wrought. Here’s the main screen showing an example. The input wave is on the top. The output wave is on the bottom. In this example, we added eight noisy (-6 dB SNR) trapezoidal pulses. After the last pulse, we continue on for a while with the same level of noise energy that we had during the signal.

LRC filtered trapezoid with -6 dB noise II
A simulation showing eight trapezoidal pulses with -6 dB SNR being filtered by an LRC filter.

In the output, you can clearly see that there were eight pulses present, though they are smoothed and distorted (and they go negative when they really shouldn’t — our trapezoids were unipolar.)

At any rate, this example illustrates some of the cool things you can do with Signal Wave Explorer. Version 1.0 is now complete and should be available for purchase in the next few days. So stay tuned!

If you wish to be notified when Signal Wave Explorer is ready for download, send us a note saying you want to be on our mailing list, and we’ll send you an email notification.

Posted in Signal Wave Explorer | Tagged gaussian noise, sampled simulation, signal to noise ratio, SNR, thermal noise, transient response | Leave a reply

Signal Wave Explorer sneak preview

Robust Circuit Design Posted on August 13, 2015 by adminAugust 13, 2015

We’ve been hard at work this summer developing a sister product to Signal Chain Explorer — a new product called Signal Wave Explorer. Much of the functionality presented Signal Wave Explorer will be incorporated into the first release of Signal Chain Explorer, our flagship product still in preview.

Signal Wave Explorer allows to you define a waveform in the time domain, pass it through various simulated circuits, and predict the output waveform in the time domain.

Time domain in, time domain out. Yet the program does its magic by doing frequency domain analysis, using Fourier Transforms.

Signal Wave Explorer is shaping up to be an intriguing program — at least that’s the reaction we get from people we’ve shown it to. Here’s a sneak screenshot of this new tool:
Signal Wave Explorer Main Screen

In the example shown above, we’ve taken a pulse train of trapezoidal waveforms and passed them through a low pass RC filter. The resulting output waveform shows the start up transients as the capacitor charges more fully each pulse, and then, just before the output stabilizes into a steady state sawtooth-like wave form, the pulse train ends and the output decays to zero.

In other words, this tool is capable of capturing the total system response — transient and steady state, forced and free. We didn’t imagine this was possible using Fourier Transforms when we first started dreaming of this product. Yet, here’s proof it can be done.

Here’s another example where we pass a single 20 μS trapezoidal pulse through an active low pass filter inverter stage with capacitive load — a circuit that has a resonance at 16 kHz. See how the output rings!

SWE Ringing Example

We expect Signal Wave Explorer to be a valuable tool for both students and professionals alike. It’s easy to spend hours exploring different waveforms, circuits, and parameters, and being surprised at what pops out. This leaves you pondering what’s going on — a great hands-on way to learn how circuits behave.

It’s also a great way to learn about Fourier Transforms — for you can also see the frequency spectrums of the input wave, system, and output wave by checking the appropriate boxes on the GUI.  For example, here’s the time domain wave and  frequency domain spectrum of our single (aperiodic) pulse:

SWE input spectrum example

Stay Tuned

We can’t wait to make this new product available. It’s looking like a fall release, so stay tuned!

Posted in Signal Wave Explorer | Tagged Fourier Transforms, frequency domain analysis, steady state response, time domain analysis, transient response | Leave a reply

Signal Chain Explorer Preview 0.9.4.6 uploaded

Robust Circuit Design Posted on August 13, 2015 by adminAugust 13, 2015

It has come to our attention that the last preview of Signal Chain Explorer, version (0.9.4.5), had some misconfigured settings for the installation, causing the prerequisites to sometimes fail installing. We’ve uploaded a new version to the website that fixes that. You can find it on the download page.

Posted in Signal Chain Explorer, Uncategorized | Tagged Signal Chain Explorer | Leave a reply

Preview V.0.4.9.5 added

Robust Circuit Design Posted on July 22, 2015 by adminJuly 22, 2015

We’ve been busy developing an exciting new feature for Signal Chain Explorer — the ability to process time domain waveforms through a signal chain and see the resulting output waveform. In our development, we’re finding that this will be an invaluable addition to the program.

Because of all this work, we haven’t added any major new functionality to the preview version of Signal Chain Explorer, but we’ve uploaded a new version to extend the preview license until Sept 21, 2015. The current one expires at the end of the month.

With any luck, we’ll have a new sister program, called Signal Wave Explorer, available for preview in a few weeks. Much of the functionality in this program will be incorporated into the first production release of Signal Chain Explorer. We can’t wait to see what y’all think of it.

So, if you’ve downloaded previous versions of SCE, you might want to refresh your copy with the latest version, so that the preview license will be extended into September. Visit the download page to get started.

NOTE: In the current pre-releases you’ll have to uninstall the old version before installing a new version.

Posted in Signal Chain Explorer | Leave a reply

Preview V.0.9.4.2 uploaded

Robust Circuit Design Posted on May 18, 2015 by adminMay 18, 2015

We here at Robust Circuit Design have been hard at work adding new functionality to Signal Chain Explorer.

New Time Domain Analysis on its way

In particular, we’ve been working on a way to handle the exploration of signals in the time domain. You’ll be able to see what these signals look like at the output. That is,  you’ll be able to see how the signal chain has affected the shape and magnitude of the wave form. And even more intriguing, you might happen to see that your signal causes ringing at the output, and you’ll see the output wave oscillating.

We’re excited about these new possibilities. However, they are not quite ready to put into a preview release.

New preview version uploaded to extend the preview license.

In the meantime, we’ve uploaded a new preview version (V.0.9.4.2). This version extends the preview  license to July 15, 2015. The older version (V.0.9.4.1) will be expiring on June 1, 2015, so we needed to get another version uploaded.

Besides the extension of the license, the new version has mostly cosmetic changes, with one main exception: When selecting a stage for adding to the signal chain, you must double-click on the stage icon to add it. Previous versions used a single-click, and we found that it was too easy to inadvertently click too many times and add spurious stage entries. Double-clicking prevents that. Also, forcing a double click to be use paves the way for us to add drag-and-drop support, which should be coming in a subsequent release.

So, if you’ve downloaded previous versions, you might want to refresh your copy with the latest version, so that the license will be extended into July.

NOTE: In the current pre-releases you’ll have to uninstall the old version before installing a new version.

Posted in Signal Chain Explorer | Leave a reply

New preview uploaded

Robust Circuit Design Posted on March 30, 2015 by adminMarch 30, 2015

A new version of the Signal Chain Explorer pre-release has been added to the website.

V 0.9.4.1 fixes errors in the thermal distortion calculations.

NOTE: In the current pre-releases you’ll have to uninstall the old version before installing a new version.

Posted in Signal Chain Explorer | Leave a reply

Thermistor example added

Robust Circuit Design Posted on March 19, 2015 by adminMarch 19, 2015

We’ve constructed a new download page, and have added a link to our first white paper / illustrated guide, called “Managing Interferers in a 12-bit Thermistor Signal Chain.”

This illustrated example guides you through the construction of a simple signal chain taking a thermistor and amplifying and digitizing the temperature signal. Fairly straightforward, you might think — until interference in the form of H-fields and power supply noise is injected into the signal chain. That’s when things get interesting.

This paper serves as a good first showcase of what Signal Chain Explorer can do in a practical setting. Be sure to check it out.

Posted in White paper | Tagged H-field interference, power supply noise, signal chain, thermistor | Leave a reply

Introducing Signal Chain Explorer

Robust Circuit Design Posted on March 1, 2015 by adminMarch 18, 2015

main-window-small

A new tool is born

Gargoyle: Signal Chain Explorer (SCE) is a software tool that helps you, the embedded system designer, explore the design space of a signal chain — the analog circuitry that goes from a sensor to an analog-to-digital (A/D) converter. The main goal of SCE is to compute the effective number of bits (ENOB) and signal-to-noise ratio (SNR) of the signal chain, and to account for all the things that affect these numbers, such as thermal noise, thermal transient distortion, electromagnetic interference, power supply and ground path fluctuations, connection wiring parasitics, peaking, and oscillations.

Featured in SCE is easy signal chain construction, easy parameter and equation entry, fast and accurate calculations, fast charting, and a built-in set of common interferer models used to trip up the unwary. All of this to aid you in determining quickly and easily what problems your signal chain may have, and then to help you in finding workarounds and exploring the boundaries of what’s possible. Doing this kind of work in preliminary design will help lead you and your company to successful outcomes.

What is a signal chain, anyway?

Third signal chain
A signal chain is that part of your analog circuit that comprises the main path of your signal, from input sensor to output A/D. The chain is represented as a series of stages — each stage comprising a chunk of circuitry serving some functional purpose. Taken as a whole these stages make up the components you use to condition your signal for proper digitization. Examples include low pass and high pass filters, multiplexors, shunts, series branches, and closed-loop gain stages. The sensor and A/D converter are also treated as stages.

Not included in the signal chain are all the ancillary bits of circuitry that help support your signal path — things like power supply regulation, protection circuitry, control switches, and the like. (We do help you model local power isolation for your stages, but not the power bus itself.)

Why gargoyle?

gargoyle flag list
The name gargoyle was first associated with the decorative water spouts on the sides of early medieval churches that often came in the form of grotesque creatures carved as stone figures. Some say these creatures, these gargoyles, were placed to ward off evil spirits. Others say the creatures were there to remind the lay people that evil lurks everywhere, and to be wary.

It’s in the latter spirit that we use the term gargoyle. In SCE, gargoyles are those aspects of your circuit that can wreak havoc, causing a loss in signal quality and causing unwanted oscillations. Examples include capacitive loads on op-amps that cause peaking, parasitics in trace wiring or cables, thermal noise, thermal transient distortion, and last but not least, interference from stray H-field and E-fields. An example of the latter might be the interference caused by placing a microprocessor clock line too close to the main signal line — a scenario that’s easy to encounter in an embedded system, if you aren’t careful.

The main purpose of SCE is to help you track down and capture the gargoyles in your embedded system — to find the lurking gremlins who are otherwise ready to pounce on the unwary circuit designer.

Gargoyle: Signal Chain Explorer is currently in beta. We hope to have a FREE preview version available on this website in a few days.

Posted in Uncategorized | Tagged Signal Chain Explorer | Leave a reply

Hello world!

Robust Circuit Design Posted on February 27, 2015 by adminFebruary 28, 2015

Welcome to Robust Circuit Design’s website!

We are glad you are here. We hope to have a preview of our new product, Gargoyle: Signal Chain Explorer, ready for download in a day or two.

Please be patient as we get this site up and running.

 

Posted in Uncategorized | Leave a reply

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