With full steam into the new year!


I don't know if it matters, but I think it would be better to run the simulation at 1.25V as that's what 1.5GHz needs and where all the problems start...

Good point Notaz. This is what we would like to do in the final simulation in time domain when we consider more nets (clock, data signals, etc...): Supply 1.05V (or 1.25V) in the VDD_MPU and see the noise generated by all other signals. However this requires more time (and information) to setup the simulation (not only selecting the additional nets in the PCB but also setup the signals with IBIS/HSPICE models). So in order to have very fast results of the design of the VDD planes TI (and all other vendors) set some targets for the VDD planes that needs to be met. If you meet these targets you can expect to have no issues. In this case ED have shared a picture of voltage drop and current density. The target established by TI for this is resistance at DC (resistance of the VDD plane). And to calculate that it is only necessary the geometry of the VDD plane and the material properties (copper, solder for vias, etc...). It is the total resistance from the SMPS to the OMAP solder balls, so the voltage does not affect this metric. The same is valid for target impedance as a function of frequency - it only depends on the geometry of the VDD planes and the capacitors. This is more important because it shows how the VDDs are decoupled. And since we are having issues at higher frequencies this is likely to be the case here.

But you are absolutely right, in order to evaluate the behavior of the VDDs and signals, a complete simulation with additional nets is required in the most sever mode of operation (or in the mode that is resulting in failure).

I´m sharing some slides below that shows all the steps for an accurate power and signal integrity analysis. Starting with DC, going to Impedance and resonances (AC) and then a complete simulation in time domain with all signals (this is where we would use the voltage and all signals information and it is where we can actually see the waveforms of the signals - last slide)

http://esss.com.br/www_cae/Ansoft_Install/pyra/ANSYS_SIwave_more_PI.pdf
 
Anyway @EvilDragon, Why didn't you mentioned the name/nick of that "community member"? He want to be anonymous or something?

I usually don't mention names if I'm not sure - and as I know he's on the boards here, I know he can show up and uncover himselt (which he did in the post above you ;))
 
Almost there! Can't wait to buy one, though I'll be waiting to see if there's a US distributor. I wanna support your store, but the final price for even the base unit would be quite a lot for me to chew after accounting for exchange rates, international shipping from Germany with a battery, taxes, possible customs fees, etc.
 
I don't now if it is because I'm not reading the forums everyday, I'm older, or what, but this seems to be coming along a lot better/faster than the Pandora did.
 
Almost there! Can't wait to buy one, though I'll be waiting to see if there's a US distributor. I wanna support your store, but the final price for even the base unit would be quite a lot for me to chew after accounting for exchange rates, international shipping from Germany with a battery, taxes, possible customs fees, etc.
Possibly @Link, although I haven't heard anything recently. In the past ED said he would be, but that will probably only happen agree the first few batches are made.
 
Possibly @Link, although I haven't heard anything recently. In the past ED said he would be, but that will probably only happen agree the first few batches are made.

Yes, Link is the one for US purchases. I asked him about this last year and he planned on getting a batch to sell in US once they're released.

Great guy to deal with, responsive, and service oriented like ED....got a Pandora from him.

His website is ithic.com
 
@EvilDragon yeah, I know that the misterious anonymous is @juliano, I saw him posting on different threads about this topic, but I was referring for the people that doesn't enter on the boards. I think him contributation need more credits because his contributations to the project are huge :D.

Anyway just my two cents, nothing more "deep" was intended with my comment :p.
 
Link writes Open Pyra <_< and the shoppe has been "Under Construction" for like a year now, I really wish I could give the link to people soon but not in this state.
 
Possibly @Link, although I haven't heard anything recently. In the past ED said he would be, but that will probably only happen agree the first few batches are made.

That sounds good. I'm just hoping buying from his shop will be cheaper than buying from ED's (for Americans).
 
The price difference will depend on the current exchange rate. Shipping costs should be way less buying from Link. If you are fine waiting, that is the better option. If you want to preorder and get one asap, order from ED and pay more (and help make sure they get made...not sure if there is a chance that it could still not happen at this point.)
 
The price difference will depend on the current exchange rate. Shipping costs should be way less buying from Link. If you are fine waiting, that is the better option. If you want to preorder and get one asap, order from ED and pay more (and help make sure they get made...not sure if there is a chance that it could still not happen at this point.)
There's always a chance of it not happening, but I think it would take some sort of HUGE catastrophe at this point.
 
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