Steven. Google. data stream clock extraction There are engineers out there working on this and one I see has a 1 chip 8 pin solution for this application. http://www.imec.be/esscirc/papers-96/109.pdf Is one for example that works from 850mb/s to 1gb/s. Thomson is making it. Clock extraction is relatively simple with a PRBS sequence of x-23 + x-15 + x-1 or better. A longer sequence yields higher performance and lowers jitter on the clock. Once you get the clock out then divide it down like we talked about to get to a more desired frequency for TTL signaling. Richard Jungert > Date: Fri, 17 Jul 2009 13:21:50 -0700 > From: steven@xxxxxxxxxxxxxxxxxxxx > To: r_jungert@xxxxxxxxxxx > CC: si-list@xxxxxxxxxxxxx; leeritchey@xxxxxxxxxxxxx; > hariprasad.palli@xxxxxxxxx > Subject: [SI-LIST] Re: LVDS to TTL converter > > > > Date: Fri, 17 Jul 2009 11:04:35 -0700 > > > From: steven@xxxxxxxxxxxxxxxxxxxx > > > To: leeritchey@xxxxxxxxxxxxx > > > CC: si-list@xxxxxxxxxxxxx > > > Subject: [SI-LIST] Re: LVDS to TTL converter > > > > > > >> From: Steven Kan <steven@xxxxxxxxxxxxxxxxxxxx> > > > >> Date: 7/17/2009 10:02:51 AM > > > >> Subject: [SI-LIST] Re: LVDS to TTL converter > > > >> > > > >>> From: prasad <hariprasad.palli@xxxxxxxxx> > > > >>> Date: Thu, 16 Jul 2009 23:42:17 +0530 > > > >>> Subject: [SI-LIST] LVDS to TTL converter > > > >>> > > > >>> Hi All, > > > >>> for one of my application , i would require some kind of adapter > > which > > > > can > > > >>> convert to LVDS signal to TTL signal over a frequency range upto > > > > 675Mhz. > > > >>> can you please suggest if there is any off the shelf component > > which i > > > > can > > > >>> use? > > > >> Venkat, > > > >> > > > >> Are you looking for a chip-level solution or a box-level solution? Do > > > >> you need 675 megabit data rate or 675 MHz toggle rate? > > > >> > > > >> 675 MHz toggle rate is awfully fast for a true TTL signal. What > > type of > > > >> receiver are you driving, and/or what voltage levels do you have to > > > >> achieve at the receiver? > > > >> > > > >> At the chip level we have used both National DS90LV032ATMTC and > > > >> Fairchild FIN1032MTC with good results (quad LVDS receiver, LVTTL > > > >> outputs), but these are only rated up to 400 Mbps/200 MHz. Looking at > > > >> their websites I don't see anything faster than that. > > > >> > > > >> If you need a box-level solution, we offer this module: > > > >> > > > >> > > http://www.pulseresearchlab.com/products/logic_trans/425N_T/prl-425.htm > > > >> > > > >> It will make TTL levels (2 V/50 Ohms) up to 300 MHz toggle rate, and > > > >> will toggle with reduced amplitude into the ~500 MHz range (though > > > >> that's not guaranteed). > > > >> -- > > > >> Steven Kan (p) 310-515-5330 x24 > > > >> > > > > Lee Ritchey wrote: > > > > Steven, > > > > > > > > I'm curious why you need to interface to TTL. There haven't been any > > > > TTL parts for some years now. Actually, I've got a few in my junk > > > > box, but I don't think that any are being manufactured now. > > > > > > > > Lee Ritchey > > > > > > Lee, > > > > > > Actually, I was responding to Venkat's request for LVDS<-->TTL > > > conversion. We make the translator box. > > > > > > We actually sell quite a lot of these. None of these are for new, > > > cutting-edge designs, but there is a lot of legacy equipment out there. > > > Some people use these for measurement and monitoring, and others use > > > them for systems integration. > > > > > > You'd be surprised at much old, slow stuff is still in widespread use. > > > We do a ton of translation to/from RS-422, because a lot of telemetry, > > > avionics, and satellite equipment uses it. People use our boxes either > > > to convert their RS-422 to LVDS and xECL for compatibility their newer > > > equipment, or they convert to TTL for use with their single-ended > > > scopes, counters, logic analyzers, etc. > > > > > > But yes, I certainly wouldn't design TTL into anything new that has to > > > run at 675 MHz. > > > > Richard Jungert wrote: > > Steven. > > > > Can you take the LVDS signal and run it thru a frequency divider > > circuit to get it down to a manageable frequency? Try to divide the > > LVDS signal frequency by say 4, 8 or 16 first then convert to TTL. I > > know it makes the TTL signal processing much more challenging but in > > this case you may not have any other choice. > > > > Richard Jungert > > We could do this*, but it all depends on Venkat's application. If his > signal is a clock, then division might work. If it's a data stream or > some other pulse train, then division obviously is inappropriate. > > Another approach would be to use something other than TTL. If, for > example, he's trying to drive input of an FPGA, some/many of these can > be configured for LVPECL input, which would run at those speeds. Of > course if it has a programmable input it might support LVDS directly, > too, which would solve his problem right there, with no additional > equipment. > > I suppose we'll have to wait for the OP to describe his application more > fully. > > * we could get from LVDS to some f/n in TTL, but not in one box. We'd > have to chain 2 boxes together (e.g. translate to ECL, then feed into > our ECL divider that has both ECL and TTL output). > -- > Steven Kan (p) 310-515-5330 x24 > Pulse Research Lab (f) 310-515-0068 > 1234 Francisco St., Torrance, CA 90502 (c) 818-620-3062 > mailto:steven@xxxxxxxxxxxxxxxxxxxx > http://www.pulseresearchlab.com > Signal Buffering & Translation for Digital Design, Integration & Test > > ------------------------------------------------------------------ > 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 > > _________________________________________________________________ Lauren found her dream laptop. 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