Hello Folks,
A while ago some of us were pondering a light-weight TDR that is small and can be hooked up to USB. Well, in the last issue of the "IEEE-Institute" one was presented and it's from this company:
Ok, it's the old PCMCIA but it will be only a small step to swing that to USB if the market is there.
Not bad... I wonder what the cost is?
I'm about to lug a spectrum analyzer over to our annex... you're up for providing design advice on that USB-based version, right? :-)
I am not an expert on that but once I was surprised how easy that is if you use "take-and-bake" parts and firmware. Took a regular Cypress PSoC and their canned USB routines. IIRC the programming part required about
20 minutes.
I wonder about the output drive requirements for some applications given the PCMCIA card's power supply limitations. With a USB device, you could incorporate an (optional) external power supply.
I expect you'd spend more time on the Windows GUI than on the actual hardware design. :-)
One option would be to use a cap to store enough energy for "the mother of all pulses" :-)
Given the quoted range they almost have to.
PCMCIA? How quaint.
They avoid specifying time resolution, and the 6.4 Gs/s sample rate is fiction. The time step is 1 ns (typ?) but the actual measurement resolution is unknown.
Looks OK for single-ended cables; way too slow for PC boards.
Hyperlabs makes a fast USB TDR, but it's expensive.
John
Surprisingly even my newest laptop still has one slot.
It's probably the usual "equivalent time sampling" and they state one inch resolution. That won't be good enough for a circuit board but their market is cables.
No idea what theirs costs either.
You sure? Most have Express Card these days, IME, and they look almost the same from the outside. They're supposed to be able to transfer data much faster than PCMCIA/PC-card.
Best regards, Spehro Pefhany
Me sure :-)
It's a Twinhead Durabook and I purposely selected that one because it's ruggedized and carries legacy ports such as RS232. Sez PCMCIA and PC-Card in the specs. Never used the PCMCIA slot so far but the RS232, a lot.
[...]
The 1" resolution isn't compatible with a 1 ns risetime step. These people are confused.
John
Don't know but they better be able to back that up because they work for NASA etc. Maybe they get to 1" by micro-scooting and finding the correlation peak of an abnormality.
I made a mistake and bought a "gaming" laptop towards the beginning of this year. It is fast with a great graphics card, but doesn't have a docking station nor an RS-232 port.
I replaced it with a used HP Compaq nw8440
---Joel
Maybe they're thinking alumina? :-) Let's see... c = 11.8"/ns in free space, so ~3.7"/ns for Er=10... hmm... still a bit of a stretch...
Nice laptop, maybe I'll buy one as a back up. Recently got a Panasonic Tough Book because I needed the Serial port and Windows XP PRO SP2. It also offers all kinds of other goodies. I noticed after browsing around it seems the Panasonic's are cheaper than that HP how ever, HP seems to be more popular. Not saying they're any better.
I also have Toshiba Satellite Pro model which has the serial port and a printer port along with a built in floppy, USB,Firewire, 10/100 Enet, 802.. Built in wireless, IR port which I really like to transport data with devices just sitting beside it.. And the usual stuff like DVD/CD burner etc...That was a computer show grabby for $250.. :)
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