Video Amplifier for long distance transmission

Hi Dustin,

you should use transmission line technique and should terminate both ends of cable with the characteristic impedance of transmission line:

en.wikipedia.org/.../Transmission_line

And use a transmission line which provides very low losses. You could insert buffers / repeaters which you power by a remote power supply.

An alternative would be the transmission over an optical fibre.

Kai

Hello Dustin,

5 kM of cable sounds expensive to me. You may also need to compensate for high frequency losses. Line of sight RF with a directional antenna would be easier but be sure to follow government rules. Is this a home project?

This used to come up a lot in security camera applications - there are chip sets out there to do this job where the receivers are lossy cable equalizers with gain ramping up a lot as you go up in frequency. Don't remember the part numbers, but I am sure you can find them - no need to recreate the wheel on this one.

Thanks Michael, thats what I thought too. Does this seem like a suitable chipset?

https://cdn.anaren.com/product-documents/MSK/Amplifiers/MSK130/MSK130_DataSheet(Rev_f).pdf

Its the only one I could find so far that had appropriate slew rate and high voltage to drive down the line.

Hey Ronald, I am handcuffed to 5 KM of 15 AWG wire. Its actually a wireline truck running a video camera down a well. The video camera needs to transmit the video data up the 5 KM of wireline to the truck, where it will then be corrected for display.

So Dustin, twisted pair driving is a well known area in both security video and VDSL - no one uses a part like you sent, For DSL twisted line drivers those go over many miles using +/-15V dual CFA type devices like the THS6212 - but that is just an example, not necesarily what you want - I have pinged some security video contacts for ideas,might get a reply - I don't think TI has anything there.

So yes, launching some pretty good swings into the cable helps, but it is really equalizing receiver that this the key to flatten out the lossy cable response.

So Dustin, I do not believe TI offers parts like these, but if they do - someone chime in - there was quite a series of Cat-5 drivers from Intersil. They did quite a bit of work in this area, with many app notes like this

www.renesas.com/.../an1307.pdf

That was an earlier one, where later there was a whole series of dedicates Cat-5 differential line drivers - I could only find a triple fast one, actually originally Elantec parts - I know they have singles as well - you can ask them,

www.renesas.com/.../el4543.pdf

And then for the equalizing recievers - look at

EL9110, ISL59911, ISL59910, ISL59603

And then there is a lunatic fringe version of all this in something called the Mega-Q Compensation - this is all about peaking the receiver gain as freqeuncy increases to equalize the rolloff described in that first app note.