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Topic: Video Amplifier Circuit Doing the Opposite! (Read 2932 times) previous topic - next topic

Grumpy_Mike

Yes but those chips have only one output and several inputs exactly the opposite of what is needed.

A standard video signal is 1V park to peak. That amplifier circuit is a very poor circuit as you can tell from the trace. All those sync pulses should be flat at the same zero volts level. This is because there is no black level clamping in the circuit and the circuit is DC coupled.
You need an AC coupled input and some clamping. Then you need four of them to drive a seprate output each. You can't chain video signals.

kg4wsv

Also take a look at Maxim's web site.  They have a variety of video amplifiers and buffers, many of which operate off a single supply (no negative voltage supply required).

-j

MatCat

Do you know any part #'s off the top of your head that would be ideal?

dhenry

Quote
Do you know any part #'s off the top of your head that would be ideal?


Any jfet would be a great video buffer: easy to bias, and good for hundreds of Mhz easily, and natively single rail supply.

Video opamps, until you are very skilled in their applications / layout, are a beast to tame.

Pavilion1984

MAX4213, EL5050 for you to start with and you will need 1 for every video output. http://www.maximintegrated.com/ have lots of good info about designing what you want to do in the product video section http://www.maximintegrated.com/products/video/ and also try google for video distribution amplifiers (VDA).


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