From: firstname.lastname@example.org (Glenn Gundlach)
Subject: Re: Is this chip suitable for video signal switching?
Date: 17 Jan 2003 21:15:14 -0800
References: <email@example.com> <3E2899CC.31C905E3@sbcglobal.net>
NNTP-Posting-Date: 18 Jan 2003 05:15:15 GMT
Gary Drummond wrote in message news:<3E2899CC.31C905E3@sbcglobal.net>...
> BarryNL wrote:
> > Hi,
> > I pulled an MC14066B chip out of an old video although I'm not sure what its
> > function was in there. However, I'd like to use to to switch a video signal
> > (ie. the composite signal in a SCART cable) and was wondering if anyone knew
> > if it was suitable for this (basically, I want to use it to multiplex
> > between the normal signal and black/white (0.3/1.0V) signals, so I can
> > overlay text onto a picture using a PIC). The data sheet just says its a
> > Quad Analog Switch/Multiplexer but I don't know if it's suitable for signals
> > as fast as video signals. I've put a copy of the data sheet on the web at
> > http://www.xs4all.nl/~barryxs/MC14066B.pdf if anyone wants to see it.
> > Thanks, Barry.
> Look at the internals of a phillips chip, and decide if you can
> duplicate the hardware in software, with a very FAST chip. You might
> find it easier to buy a chip. Just producing video is easy, check
> Circuit Cellar for the design contest results for a few years ago, then
> extrapolate from them to see if you can detect the vertical sync, count
> lines and display a graphic while stopping the video at the same time...
> Good luck,
Depending what you're trying to do with the output video, you will
also have issues with DC levels, AC levels and source to source
timing. When doing pixel level switching, 120nS will look rather
nasty. Also, 4066 family devices have some switch glitches. You might
check out some Elantec video switching chips. Analog Devices also
makes some outstanding multiplexers. AD8180, AD8182 and AD8184 come to
mind. Check out Maxim,too.