Monday, August 30, 2010

Reminder Photovoltaic Test Webcast August 31st (Tomorrow!)

Just a reminder that I will be co-hosting a photovoltaic test webcast on August 31st (tomorrow). The webcast is entitled "Solar Photovoltaic Testing for R&D, DV, and Manufacturing." Hope you can make it!

Click here to register

Tuesday, August 24, 2010

The Battle of the Ultra High Bandwidth Oscilloscopes Continues

Back on 4/27/10 Agilent came out with the Infiniium 90000-X series oscilloscopes, which featured the highest real-time bandwidth at a ridiculous 32 GHz (see my post on it click here). That beat the previous leader, Tektronix by over 10 GHz. Scopes is a highly competitive market with Tektronix currently leading the market, Agilent in second, and Lecroy a distant third. With Tektronix as the market leader it was only a matter of time before they responded to their performance leadership being taken and they did (well kind of). Tektronix announced that by using silicon germanium (SiGe) technology found in IBM's 8HP chips in the high speed input circuits of their scopes they can achieve real time bandwidths of over 30 GHz. Tektronix stated "The 130nm SiGe BiCMOS technology offers x2 performance over the previous generation and targets delivery of oscilloscopes with real-time bandwidth beyond 30GHz.” For their 32 GHz scopes, Agilent uses the non-silicon technology of indium phosphide (InP) in their high speed input ICs. 
In Tektronix's press release they just said they have the technology but gave no mention of when this new technology would be seen in a new scope. It seems to me that they are just trying to tell their current high bandwidth scope customers that its coming so don't run out and switch to Agilent quite yet give us a chance to catch up. If they did have a design that was right around the corner my guess is they would have never made this announcement so I wouldn't expect to see a Tektronix scope break 30 GHz for at least another year probably more. The question is how high will Tektronix go in real-time bandwidth with this new chip technology? My guess is 40 GHz because you have to make a large leap frog over the competition to hold the top performance spot long enough to make the investment worth it (and trust me at bandwidths this high the investment is huge). What is your guess?

For more information on Tektronix's press release click here

For more information on Agilent's Infiniium 90000-X series click here  

Wednesday, August 18, 2010

You Can Get a Watchdog with Your Power Supply?

Watchdog timers are common place in the world of computing and embedded systems. It’s the watchdog timer’s job to notice if a computing device, such as a microcontroller, has hung up or froze. If it has the watchdog timer performs a reset. The whole thing works by setting the watchdog timer for a specific count. Once the computing device starts operating the watchdog timer starts its counting. It is the computing device’s job to send a command to the watchdog timer to let it know it is still running (referred to as “kicking the dog” or “feeding the dog”). Once the watchdog gets that command it resets  and starts counting again.
Recently Agilent added watchdog timer functionality to its N6700 modular power system family of supplies. The N6700 watchdog functionality works similar to the description above with the “feed the dog” timer reset coming from the IO connection with the computer. A timer reset occurs whenever SCPI traffic from the computer occurs. If the watchdog timer does not receive a reset in the user’s specified count it goes into a protection mode and shuts its outputs off.
The whole idea of adding this functionality developed from customer feedback. The customer was running durability tests on multiple DUTs. The tests lasted for weeks or months at a time. During the tests it wasn’t uncommon for the computer to freeze or crash (damn you windows). During testing the supply outputs were cycled high and low. If the computer goes down while the supplies are on the high end and there was no one around to notice the DUTs would be destroyed. From there the tests had to be started from scratch with new DUTs, very costly. The moral of the story here is do not be afraid to tell your test and measurement company reps what capabilities you need because they do listen!

Thursday, August 12, 2010

Waveform Sequencing Capability is now in the GP Realm

As Moore’s law continues to chug along FPGAs, memory, ASICs, and the like continue to get faster and cheaper. This has led to a steady trickle down affect of features, speeds, and specifications that in the past were only found in high price instrumentation move into general purpose (GP) instrumentation. One recent example being waveform sequencing capability. Waveform sequencing is the ability to seamlessly transition (no discontinuities in the output) from one waveform in memory to another waveform somewhere else in memory. Waveform sequencing allows you to create complex easily reconfigurable waveforms by pasting together other simpler waveforms in memory. It is analogous to creating a custom playlist on your MP3 player. Some of Agilent’s recent product releases that provide waveform sequencing capability include the N6705A DC Power Analyzer (see image) and the just released 33521A and 33522A 30 MHz function / arbitrary waveform generators. The N6705A has a high power current or voltage arbitrary waveform generator in it with waveform sequencing capability. The 33521A and 33522A sequencing ability allow you to transition from one waveform to another using either cycle counts or triggers. For example let’s say I have waveform A, B, and C stored in my 33521A’s memory. I could create a complex waveform using a sequence that repeated waveform A 27 times, then runs waveform B continuously until a trigger is received, and then runs waveform C 2 times. Below is a link to a video staring yours truly that demonstrates the waveform sequencing capability of the 33521A and 33522A.

33521A and 33522A Sequencing Demo

Friday, August 6, 2010

Capturing, Transferring, and Manipulating Arbitrary Waveforms on the 33521A and 33522A

Back on my Aug 1st post I mentioned one of my favorite things about Agilent’s new 3352xA family of 30 MHz Function / Arbitrary Waveform Generators is how easy it is to create and manipulate waveforms. In this post I will build on that statement. Let’s say you have a digital or analog waveform that you want to recreate on the 33521A or 33522A. All you need to do this is a USB thumb drive and a scope that can save signals in a .csv file, like Agilent’s 7000B series of scopes. In the past this required a computer, connecting both instruments to the computer, and special software. Not anymore! Below is a link to a video that shows how quick and easy it is to transfer a waveform from a scope to the 33521A or 33522A.

33500 Series Scope Capture and Transfer

Now that we have our arbitrary waveform on our 33521A or 33522A we may want to manipulate it to test the fault tolerance or noise immunity of a DUT. We can easily manipulate an arb using the built-in waveform editor as shown in the following video.

33500 Series Scope Waveform Edit

Besides just using the waveform editor we can also manipulate our waveform using different modulation schemes. For instance you could use the “Sum” feature under the modulation menu to add Gaussian noise or a simple sine wave to simulate power line noise to the signal. Hopefully I will get to more on the “Sum” feature in a later post.

Wednesday, August 4, 2010

Photovoltaic Test Webcast August 31st

I will be co-hosting a photovoltaic test webcast on August 31st. The webcast is entitled "Solar Photovoltaic Testing for R&D, DV, and Manufacturing"

Click here to register

Sunday, August 1, 2010

Agilent's New Family of 30 MHz Function / Arbitrary Waveform Generators: single channel 33521A and dual channel 33522A

Today August 1st Agilent is introducing its new family of 30 MHz Function / Arbitrary Waveform Generators. There is a one and two channel version, the 33521A is the one channel and the 33522A is the two channel version. They really raise the bar in the function / arbitrary waveform generator instrument class and here is a quick run down of some of their key features:
- 30 MHz sine, square, and pulse bandwidth
- 250 MSa/s 16 bit true point-by-point arbitrary waveform generation
- Dual-channel mode with independent or coupled channels
- 1 MSa waveform memory standard, 16 MSa memory (optional)
- Arbitrary waveform sequencing capability
- < 40 ps jitter and less than .04% total harmonic distortion
- All the standard modulation capability you would expect plus waveform summing

I have been biting my tongue waiting to blog about this awesome product family! Over the last couple months I have had the privilege to use and test the 3352xA family since its early days as a prototype. One thing I love about the 3352xA family is how easy it is to create complex waveforms. First off there is the 250 MSa/s 16 bit arb with 1 Msa memory standard to create complex arbs. Besides that there is a long list of other features that allow you to create and manipulate waveforms. I am not going to get into them here but I will in future posts.

Besides being rich in features, the 3352xA is just a 'sexy' fun instrument to use. It was comparable to my first computer or smartphone where I just couldn't take my hands off of it and had to explore and test every feature. It comes with a large, color, graphical display and has a hardkey / softkey setup (like a scope) that makes it easy to navigate its many features. Now the case could be made that I am a little bias since I work for Agilent so I encourage you to check it out yourself by following the link below or contacting your Agilent rep.

Agilent's new 3352xA line of 30 MHz function / arbitrary waveform generator