Author Topic: Looking for Cheap, Ultra Fast LEDs (2-3ns)  (Read 7155 times)

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Offline suppermanTopic starter

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Re: Looking for Cheap, Ultra Fast LEDs (2-3ns)
« Reply #50 on: February 02, 2020, 04:58:07 pm »
I hope that wasn't a surprise!

I'm new to this... so yes! In a delightful / dreadful way it was a surprise to see radiation be stronger than the signal depending on the layout.

We don't need to know why/what the 1cm air gap is for, and you've given reasons why some solutions aren't useful, but without knowing what/if anything is useful I think some of us will be finding the conversations just frustrating. :)

I can see that this can be frustrating and I'm sorry. Also sorry if I came across as a bit aggravated.. don't mean to be. Clearly you have experience in this space that exceeds mine.. My only advantage is that I MUST make it work.. so I will.

I need to get a video signal to another part of the design that can not have a physical connection to the signals origin for mechanical reasons. It is not like a slip-ring.. but perhaps it is best if you think of it as such.
 

Offline m98

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Re: Looking for Cheap, Ultra Fast LEDs (2-3ns)
« Reply #51 on: February 02, 2020, 05:44:35 pm »
I need to get a video signal to another part of the design that can not have a physical connection to the signals origin for mechanical reasons. It is not like a slip-ring.. but perhaps it is best if you think of it as such.

Maybe take a look at the ST60A2G0.
 

Offline suppermanTopic starter

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Re: Looking for Cheap, Ultra Fast LEDs (2-3ns)
« Reply #52 on: February 02, 2020, 06:22:08 pm »
Maybe take a look at the ST60A2G0.

That looks Fantastic!! I can't find any pricing.. or distribution. Any idea on price or how to buy?
 

Offline suppermanTopic starter

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Re: Looking for Cheap, Ultra Fast LEDs (2-3ns)
« Reply #53 on: February 02, 2020, 06:46:32 pm »
I reached out to ST.. will post here when I hear back. I would do $5-6 per chip.. what are the chances?

Does anyone think I'll run into extra issues during emissions approval if using a chip like this? 60Ghz probably does not "travel" too far.
 

Offline StillTrying

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Re: Looking for Cheap, Ultra Fast LEDs (2-3ns)
« Reply #54 on: February 03, 2020, 02:28:14 am »
I hope that wasn't a surprise!

I'm new to this... so yes! In a delightful / dreadful way it was a surprise to see radiation be stronger than the signal depending on the layout.

Oh dear! In reply#26 you seemed to be hinting at driving 100s of mA <<3ns edges to speed up the LEDs switching, I imagined multiple channels switching at exactly the same time only 1cm from the fast photo diode amps! But don't worry, I think everyone finds out the effects of fast edges the hard way.

In my simple LED switching experiments a 5mm UV seemed to have faster rise and fall times than most, but each edge ended in a horrible curve so I didn't try any further.
I don't know how you're turning the small photo diode currents back into a 400Mb/s logic level, but I know it's a lot harder than 'just use a 2ns photo diode'. :D

The new? ST60A2G0 looks like it could be a good solution.

I don't know much about high speed stuff at all. :)
.  That took much longer than I thought it would.
 

Offline suppermanTopic starter

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Re: Looking for Cheap, Ultra Fast LEDs (2-3ns)
« Reply #55 on: February 06, 2020, 09:15:01 pm »
WOW.. got some feedback on my request for info on the ST60A2G0.

They say it is "Classified"!  What??? The press release has it positioned as a low cost chip for consumer products..
They seem to actually mean that is is Classified.. as in security clearance required rather than DNA.

They did tell me to call a number which I did. But I think this is a dead end.

 

Offline dmendesf

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Re: Looking for Cheap, Ultra Fast LEDs (2-3ns)
« Reply #56 on: February 06, 2020, 11:43:16 pm »
There's a "databrief" of this device. Seems the antennas are not embedded in the BGA. (I've seen others that do... ). This implies in RF voodoo without instrumentation (who can measure anything at 60GHz?) So the manufacturer must go "hand to hand" to make it work/pass compliance. This sort of thing can only pay itself if you order large orders... So they don't want to talk with you.
 

Offline StillTrying

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Re: Looking for Cheap, Ultra Fast LEDs (2-3ns)
« Reply #57 on: February 07, 2020, 12:27:54 pm »
I think what's classified about the ST60A2G0 is that they probably haven't managed to mass produce any yet. :P
.  That took much longer than I thought it would.
 


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