This might be obvious, but it's worth a mention anyway. Absent a PLL, the LCDs I've worked with generally have static clocking down to DC. It is conceivable that the design might use dynamic logic speed up on-panel circuits built with amorphous silicon, but it is hard to believe that the resulting minimum clock would be so high. So, take a close look at the spec sheet and check if the 25 MHz number is actually a minimum for the maximum clock rate, i.e. the thing will crap out at some faster rate, but never at a slower one. Regards, Orin On Wed, 2 May 2007 4:21:53 +0300 Dimiter Popoff <dp@xxxxxxxxxxx> writes: > Posted this to two newsgroups, then I thought actually I might have > better chances to find someone in the TFT module industry via the > Si-list, so here it goes. > > I have been looking around for a TFT module for a design (5" to 8" > sized, 800x480 min.,thin) and found some really good looking. > The problem I have is that some of them specify a minimum dot > clock > frequency, typically well above 25 MHz. > Now apart from a PLL they may have inside the module I can think > of little reasons why they need that; and I have not heard of such > a > thing, but I am far from the insides of these (hence my posting > :-). > I could pretty well live at a 30 Hz or even 20 Hz frame rate, > which would mean 16 MHz clock or below, thus lower power, > less memory bandwidth etc. > TFTs don't flicker, I have played with the first one I had 5-6 > years > back and there was absolutely no visible benefit of increased clock > frequency. > > Anyone know why this minimum clock spec? Any knowledge on that? > Some of the best fits I find do specify it and it is in conflict > with > a really major simplification I can make to the design.... > So my hope is that this spec is put in order to keep some high > enough > frame rate to satisfy some common controller thing, not really a > must. > I'll try to ask the manufacturers directly, but perhaps I have a > better chance to find out something via usenet. > > Thanks, > > Dimiter > > ------------------------------------------------------ > Dimiter Popoff Transgalactic Instruments > > http://www.tgi-sci.com > ------------------------------------------------------ > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject > field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > @freelists.org with 'help' in the Subject field > > > List technical documents are available at: > http://www.si-list.net > > List archives are viewable at: > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > > ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu