Good luck! Alan ---------- From: treg-approval To: treg Subject: RE: Status of prTBR 21 List-Post: [email protected] Date: 26 September 1996 11:34
Alan, Sorry to say I've made this a more protracted complaint than I intended. I'll just make one more observation before I end my ranting. The current limiting specs the French are insisting on will and has created a game scenario for certain engineers to play. i.e. how do I pass the current limit approval. Even though the dissipation will ultimately destroy the PC Card DAA and/or kill V.34 and V.34+ performance. The French probably had FETs in mind when they came up with the TBR 21 template, but FETs are unusable in a V.34 holding circuit. I won't try to explain why, it would take too much verbage. I will no longer belabor this issue, I consider my spleen vented and will play the game of designing to TBR 21 :). Regards, Duane. ___________________________ On Thu, 26 Sep 1996, Charlton, Alan wrote: > > Well, you can say that until you're blue in the face, and I'd agree with you > every time, but the fact is that if pushed, France Telecom would be likely > to try and get AFNOR to change the YES vote to NO. We got a flavour of this > last week from the FT people at the TE5 meeting - they've got something up > their sleeve anyway. Everyone is well aware of the power dissipation > problem, but that's the way it is. The hard fact of life is that PCMCIA > modem manufacturers will have to suffer for the greacter good of the rest of > the industry...sorry! > > Regards, > Alan > ---------- > From: treg-approval > To: treg > Cc: treg > Subject: RE: Status of prTBR 21 > Date: 25 September 1996 10:28 > > Alan, > > About midnight last night, in a moment of inspiration, I was able to come up > > with a holding circuit that has DC characteristics falling in the middle > of TBR 21 Figure 4. It is the strangest holding circuit I've ever > design and V.34 has no problems with it. > > The French may get testy when pestered about DC characteristics, but it > is almost impossible to design a PCMCIA card that will survive current > limit testing. I don't believe any PCMCIA cards will pass TBR 21 > approvals. The cards will simply not dissipate 2.2 Watts and survive. > > Regards, Duane > ______________________________ > > On Wed, 25 Sep 1996, Charlton, Alan wrote: > > > > > Glad to help - I want TBR 21 as badly as anyone! It's worth noting that > the > > DC characteristics are unlikely to change in the short term, and the > French > > started getting shirty when pestered about it... > > > > Regards, > > Alan > > ---------- > > From: treg-approval > > To: treg > > Cc: treg > > Subject: RE: Status of prTBR 21 > > Date: 24 September 1996 14:15 > > > > Alan, > > > > Thank very much for the update. I'm just starting the design of a > > universal DAA that hopefully will meet all TBR 21 requirements. > > > > All of the DAA circuits meet TBR 21, but I'm still a bit stymied by the > > holding circuit templated that requires limiting the line current to 60 mA > > when sourced through a 230 ohm resistor. I think the design is very close > > to meeting the template. I will know in next day or two. > > > > Again, thanks for the update. > > > > Regards, Duane > > >
