DIY? 8MP Video Balun for custom PCBs?

[rajhlinux]

Hello, I am looking for an 8MP video balun product that I can buy or make which is small and capable of being soldered directly to a PCB.

I am making a custom analog 8MP DVR and camera system and I want to use RJ45 as the transmission line. For this I need a balun. I am sick and tired of using those common bulky baluns that come in pairs. They become a nightmare for wire management and clutter everything into a huge mess. They also actually damage the DVR BNC connectors over time just by sagging and dangling from them.

I basically want a small 8MP balun that is PCB-ready and can be soldered directly to the PCB board of the DVR and camera. I think the best option is to look into active baluns which I know come in IC packages but a passive option is also good to have.

Note: I did saw an active video IC, but its not suitable for 8MP (4K) analog video signal and not compatible for all protocols "HD-CVI/TVI/AHD/CVBS".

Any advice on the passive or active options will be much appreciated if you have experience.

 

[justinharris92]

For a passive solution, you might look at small SMD video isolation transformers rated for HD analog bandwidth and design a matched impedance network around them. Have you checked transformer specs for frequency response up to 4K CVI TVI ranges to ensure minimal attenuation?

 

[rajhlinux]

Thanks for your response, I couldn't find any SMD video isolation transformers. Not sure which transformer are in specification for frequency response to 4K CVI TVI ranges.

You seem to be knowledge about this Analog signal processing and would be great if you can provide some more info on this. I was also looking into active ICs but couldn't find nothing for 4K or above.

I realized this is making my life more difficult so now I'm planning to simply buy Sony IMX raw camera modules and interface it to FPGA for image processing using MIPI C-PHY interface and then have it output raw 12-bit video over fiber using serial transceivers or high bandwidth LAN. This is so much more cheaper and easier (specially buying parts) to do than playing with video isolation transformers.

However, for the sake of clarity and knowledge would really like to figure out how to make my own video isolation transformers for 4K CVI/TVI.

Thanks.

 

[Martaine2005]

Try this company

https://www.lundahltransformers.com/wp-content/uploads/datasheets/1575.pdf

 

[rajhlinux]

Highly doubt it can support 75Mhz to 100Mhz bandwidth needed for 4K, datasheet only supports 11 MHz.

Will check if they have anything better.

Thanks.

 

[Martaine2005]

Highly doubt it can support 75Mhz to 100Mhz bandwidth needed for 4K, datasheet only supports 11 MHz.

Will check if they have anything better.

Thanks.

Yes, which is why I said to try the company.

 

[rajhlinux]

Thanks. I checked the company and they do not have anything near 70-100MHz.

As a matter of fact, no one in the industry has such a discrete PCB or SMD form transformer/balun designed for 4K video. I read there is a way to do this using RF transformers but it will require a lot of R&D, I rather ask an expert and avoid questionable R&D.

It is only mass produced by Chinese CCTV companies for 4K, they’ve done the R&D on it.

Oddly enough, this is only one of the trillions of components they also do not sell as discrete components or in PCB or SMD form. They only sell it in a ready made consumer product with the packaging box.

I could ask some direct manufacturers who make the complete ready made 4K balun boxes on Alibaba and most likely they can supply the discrete components.

 

[Delta Prime]

I am making a custom analog 8MP DVR and camera system and I want to use RJ45 as the transmission line.

No, you’re not…

I rather ask an expert and avoid questionable R&D.

How would you know the difference?

buy Sony IMX raw camera modules and interface it to FPGA for image processing using MIPI C-PHY interface and then have it output raw 12-bit video over fiber using serial transceivers or high bandwidth LAN. This is so much more cheaper and easier (specially buying parts) to do than playing with video isolation transformers.

Stick with that.
Tell us how it goes… for kicks and giggles.