Agilent DSA-X93204A 33Ghz 80Gs/s Teardown - Page 1
Forum section: electronics / testgear

author: free_electron
author_rank: Super Contributor
timestamp: February 24, 2013, 07:44:28 pm
content: Grab a chair, sit down, keep hanky at bay because we are entering eye-watering territory.It's not exactly a full teardown but this is as close as you'll ever get to this 'Unobtainium' Scope.The short specs :- 33Ghz analog bandwidth ,- 80 gigasamples per second- 2.1 Billion points of trace memory.Cost ? More than your average house. Base model starts at 300K$ and a full blown all options tops well over half a million dollar.The BeastFor the non-believers : Yes we can ...This machine was under development for many years and the designers were in uncharted waters. They tapped into the know how of Agilent's RF division and even those guys were scratching their head. Never been done before ...Silicon germanium ? too noisy. Gallium Arsenide ? Too slow .. Indium Phosfide then ? Ah, but our semiconductor fab in Santa Rosa can run that ... Yes boys and girls. This machine is fully built in USA. While most of the scopes are assembled in Agilent's Malaysia operations, this beastie is not. It was designed by Agilent's Scope operations in Colorado , the Santa Clara people did the digital guts and the Santa rosa operation made the analog front-end and A/D converter.The input :The high bandwidth meant that they had to let go of the classic BNC or even standard SMA connectors as even those top out at 10 to 12Ghz... Instead Agilent opted for precision 3.5 mm connectors with built-in torque control. Twist the big grey ring and when it 'clicks' it means you now have applied sufficient torque to guarantee correct and repetitive performance. Besides the input connector there is another multipin connector that provides power and communication with the active probe heads. The active probes store s-parameters which the scope reads and uses to compensate the signal pathway, effectively shifting the plane of measurement to the probe tip and not the machine input.Even then, the accuracy may not be enough for what you want to do so the scope has a built in calibrator output .This delivers a 15pS rise time pulse pattern ( long dead time active high , followed by a low-high-low-high transient ) the scope uses as a kind of TDR measurement to compensate it's signal path further.The 3.5mm connector is almost SMA compatible. Even though they will mate , long term damage may be inflicted and Agilent has so called 'port-savers' that you can screw into the connectors. The input will take a 5 volt pp signal without blinking. Beyond that you need attenuators.Needless to say the cables and attenuators cost a fair amount of money as well... the little attenuator above costs 438$... the attached cable another 520$ ...So what makes this thing tick ?The magic happens in the front-end hybrid.link to the full blown picturehttp://www.siliconvalleygarage.com/eevblog/unobtainium/ad-ori.JPGThe chip closest to you is the A/D convertor. the chips furthest away are the input amplifiers ,The chips in the middle are (i assume) the triggering logic.The A/D is fed power and control signals through the traces going sideways. This is relatively low-speed and parallel. The data is streaming out through 8 differential unidirectional serial buses. It's the only way to get the data out at this breakneck speed. This module is a cross breed between a hybrid ( the blue area ) and a BGA ( the green area. ) Chips are bonded directly to the substrate and the hybrid is bonded in turn to the bga area ( you can see the little solid gold bond-wires of you zoom in ).view from the other side :link to the full blown picturehttp://www.siliconvalleygarage.com/eevblog/unobtainium/ad-front-ori.JPGthis shows the input amplifiers in close up as well as the input protection and connection.Notice the wide trace coming down from the input amplifier , going through a 'tunnel' and ending, seemingly, nowhere ?well, let's flip the chip over shall we :There they are : the input connectors. The single ended signal could not be transported to the amplifier through the package. So they just bolted RF connectors on the chip's back... Voodoo-territory..The A/D output buses are fed into another ASIC that demuxes and parallelises the streams into fast GDDR5 memory. Beyond that , it's just another infiniium scope.I was able to use this machine to test the famed Jim Williams Pulse generator and record once-and-for-all it's rise time.And here's me :Yes, i can use this thing. It's no more complicated than a regular infiniium scope. Childs play. The only thing you need to be aware of is to run probe-compensation when you are getting ready to measure. Connect your measuring plane to the calibrator output , click the probe compensation menu and let the scope figure out what is the behavior of the stuff you attached. This effectively shifts the 'system input' to the tip of the cable.Making measurement is drag-n-drop just like with any infinium. The user interface is extremely responsive and button pushes or encoder clicks deliver instantaneous screen update. As usual , everything is done by raw hardware and the built in computer only serves as user interface , file storage and remote operation. While it runs windows you don't notice it at all (unless you start saving screenshots etc , then the traditional windows explorer opens). It's main cpu isn't even that powerful.The machine is silent enough you can leave it on your desk. It has 12 big fans forcing air over the digitizer board but since they used the whole side of the machine to convey the airflow there is virtually no fan noise.

author: firewalker
author_rank: Super Contributor
timestamp: February 24, 2013, 07:52:58 pm
content: Video! Video!Alexander.

author: M. András
author_rank: Super Contributor
timestamp: February 24, 2013, 08:02:19 pm
content: i bet if you open it up your workmates will be breathing over your shoulder

author: free_electron
author_rank: Super Contributor
timestamp: February 24, 2013, 08:32:34 pm
content: I did the work at Agilent's headquarters in Santa Clara. I did not want to throw this thing in the back of my car and then get rear-ended on the way home. That would have been a very bad day. Opening the machine itself is a no-no... but at least they gave me one of the A/D chips. they casually put it beside the scope ( you can see it in some of the pictures above. ) Those 2 chips alone are half the cost of the scope...I have some video of the machine working. i need to mix it with the video of the agilent archives ( i visited their 'museum' later that day ), more of an archive collection of everything they ever made. Some pretty cools stuff and the curator knows his stuff in and out. I discovered some pretty interesting stuff while there , but that's for another post.

author: bingo600
author_rank: Super Contributor
timestamp: February 24, 2013, 08:38:38 pm
content: I wonder if they would let me trade my DS1102E inNow that i don't have a house , worth that much ....I feel the mouth water rising ....For that one in the "contest" i might even ... slightly consider to join facebook to "like them"But i allready like "IT"Agilent/Bingo

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 24, 2013, 08:42:45 pm
content: Amused by that measurement of 8.27091ps - I wonder how many digits are meaningful - the last 1 is how long it takes for light to travel 300nm...

author: AndyC_772
author_rank: Super Contributor
timestamp: February 24, 2013, 08:52:45 pm
content: Meh... I think I'll wait for the 50 GHz version

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 24, 2013, 08:57:45 pm
content: Are there any cables running from the A/D chip to the front panel connectors? It looks like the spacing of the connectors on the chip is much closer than the connectors on the front.And the links to the jpg pictures on your website all give me a rudimentary home page, with missing pictures and such, both with IE and chrome. Anyone else noticed this?

author: free_electron
author_rank: Super Contributor
timestamp: February 24, 2013, 09:00:16 pm
content: oopsioe. links have problems...fixed.$%^& linux servers with their case sensitive filenames... what moron decided it would be a good adea to make a filesystem that is case sensitive. Probably some bloody c-programmer...

author: free_electron
author_rank: Super Contributor
timestamp: February 24, 2013, 09:04:08 pm
content: Quote from: AndyC_772 on February 24, 2013, 08:52:45 pmheh. there is a Q version of this machine that does 62Ghz bandwidth.... but it's not for sale... yet ...

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 24, 2013, 09:04:42 pm
content: Quote from: free_electron on February 24, 2013, 09:00:16 pmYeah, I still screw up on that now and then... for the last 20 years

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 24, 2013, 09:11:50 pm
content: Is this what it looks like, a communication problem between design and engineering?

author: free_electron
author_rank: Super Contributor
timestamp: February 24, 2013, 09:13:34 pm
content: nah. this chip has been manhandled and the bondwires squashed. optical illusion.

author: firewalker
author_rank: Super Contributor
timestamp: February 24, 2013, 09:16:57 pm
content: Quote from: free_electron on February 24, 2013, 09:00:16 pmActually it was the price/cycle of the first computers. For a computer "a" is different than "A". Case sensitivity saves cpu cycles.Alexander.

author: firewalker
author_rank: Super Contributor
timestamp: February 24, 2013, 09:19:42 pm
content: Quote from: free_electron on February 24, 2013, 09:13:34 pmOh, the chips are actually opened? I thought there was a glass or something. The chips inside a working instrument? Also open?Alexander.

author: AndyC_772
author_rank: Super Contributor
timestamp: February 24, 2013, 09:31:14 pm
content: I think "open" might be stretching a point; if I recall correctly, the gold plated ground ring all the way around the chip is soldered to the PCB, forming a 360 degree seal against the board.

author: free_electron
author_rank: Super Contributor
timestamp: February 24, 2013, 09:37:31 pm
content: the chips in hte instrument are closed of course. this is an open device they have laying around to show off to potential customers ( and shove up the competitions nostril's )

author: EEVblog
author_rank: Unknown
timestamp: February 24, 2013, 09:43:24 pm
content: Quote from: free_electron on February 24, 2013, 07:44:28 pmAnd if it's possible, any twisting motion of the connector into place likely ruins your calibration too, as the metal rubbing changes the accurate dimensional tolerances and ruins your VSWR.I assume the connector would be designed to prevent a ham-fisted user from doing that?Dave.

author: EEVblog
author_rank: Unknown
timestamp: February 24, 2013, 09:51:50 pm
content: Quote from: free_electron on February 24, 2013, 08:32:34 pmI had the same fear when I transported the $140K 90000 scope on the back seat of my car.It was delivered to my home, and the custom shipping crate wouldn't fit in the car, so I had to wedge it between the front and rear seat.Dave.

author: firewalker
author_rank: Super Contributor
timestamp: February 24, 2013, 09:56:26 pm
content: I would put it between the front and rear seat by default tbh.Alexander.

author: Unknown
author_rank: Unknown
timestamp: February 24, 2013, 10:51:53 pm
content: Truly stunning, and double cool!!not sure about the Lego car wheel dials though ;-)

author: BravoV
author_rank: Super Contributor
timestamp: February 25, 2013, 01:34:44 am
content: Thanks for sharing this and looks like the newer revision at the JW pulser pcb with the extra waveguide trace work very well aren't they ? Great to see that !So ... for JW pulser buyer will get that cool hybrid ic as a souvenir from Agilent right ? ... right ?

author: AndyC_772
author_rank: Super Contributor
timestamp: February 25, 2013, 08:03:45 am
content: What are the probes like for this machine?I've used Agilent's active differential probes with a bandwidth of a few GHz, but I presume they're nothing like this. What can you possibly connect to a circuit that won't completely wreck the signal at these frequencies?

author: fmaimon
author_rank: Unknown
timestamp: February 25, 2013, 09:44:35 am
content: There is a video inhttp://www.home.agilent.com/en/pd-1820590-pn-DSOX93204A/infiniium-high-performance-oscilloscope-33-ghzYou can see the probe in there...

author: nctnico
author_rank: Super Contributor
timestamp: February 25, 2013, 10:55:15 am
content: Quote from: firewalker on February 24, 2013, 09:56:26 pmAnd use the seatbelts...

author: muvideo
author_rank: Frequent Contributor
timestamp: February 25, 2013, 11:06:50 am
content: How does it compare to my OWON ?Thanks, F_E for sharing, about the pulser,probably I missed some posts, what is thefinal measurement you obtained from thebeast?Fabio.

author: fmaimon
author_rank: Unknown
timestamp: February 25, 2013, 12:15:08 pm
content: From the last post of the Jim Williams pulser threadQuote from: free_electron on February 22, 2013, 09:39:54 pm

author: Lukas
author_rank: Frequent Contributor
timestamp: February 25, 2013, 06:36:42 pm
content: I'm wondering how they managed to pump 80GB/sec (assuming 8 bits per sample) through only 8 lanes. That would lead to 80Gbit/sec on each lane, effectively 80GHz?? Or do they employ PAM to get the Frequency down?