15+ Transistors in single IC

VG

·Hi,
·· I am trying to control Video, Audio connections from cable box to the TV. I have about 15+ such connections from various boxes (set top and bottom boxes). My idea is to control them using prop pins and use transistors to toggle on/off of those connections. Is there a single IC package that contains 15+ transistors?? I would greately appreciate if you can mention Digikey part number.

Sincerely,
Venkata.

StefanL38

Hello Venkata,

I'm not an expert about video-signals but,
I guess for switching viedo-signals you can't use a simple transistor as video-signals are high-frequency signal.
Yes it's true you don't want to generate video-signals you just want to switch video-signals. But there are other
things you have to take care of too. Like 75 Ohm resistance. Capazitive effects of the transistor.
The signals would have to be DC with added AC to pass the transistor properly.

interesting thread here

and here

best regards

Stefan

whicker

Something from Analog Devices like the ADG706, but get out your analog circuit design skills.

VIRAND

I've seen some... I think some IC part numbers that start with ULN might have 8 per chip.
To use for video you need to use them as linear amplifiers which might be hard with those ICs because they
have common emitters and otherwise just transistors alone are not enough, although similarly
even a handful of Vacuum Tubes from the first half of the 1900's are equally capable of processing video.

I think what you really want is a few chips either 4051, 4052, or 4053 CMOS digital controlled analog switches.
4051 is an 8-way switch. 4052 is two 4-way switches, 4053 is three 2-way switches. Imagine a handful of
relays that are electronic instead of mechanical. Very simple. You have 8 audio+video devices which need
to be switched to one audiovideo device, use two 4051's and send a number from 0 to 7 to both chips.
It can be either one camera and 8 TVs, or 8 cameras and 1 TV. You can route signals any way you like with
those chips, even connect eight 4051's to one 4051 and choose to communicate with any of 64 different places.

All these I mentioned are cheap, common, and less than $1 per chip whenever I bought them.

KMyers

You might look at Maxim Semiconductors. They make Vid/Aud switchs that can interface to micros. They maintain the
75 ohm system and modulation effects.

Ken

Bob Lawrence (VE1RLL)

CMOS Analog Switches 4066

www.fairchildsemi.com/ds/CD%2FCD4066BC.pdf

Post Edited (Bob Lawrence (VE1RLL)) : 10/1/2009 12:17:23 AM GMT

VG

Hi VIRAND. The IC is NTE 4501 (or 2 or 4 or 8). The compatible product at Digikey is HEF4051B by Philips. I found·it with Digikey for $0.58 a piece. Like Stefan said I am aware of the frame related mismatch. I think it should realign in two frames. I will try this once I receive the package.

Venkata.