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Hi there,
You might want to take a look into the Passive Component Designer from Cadence (available up to MMSIM7.11)
and/or a EM-Solver like Sonnet. Both Tools require technology information:
-sheet resistances
-epsilons
-layer thicknesses
As far as I can remember PCD reads the data from the...
Your PSRR response does not really look like a PSRR response at all.
Looks more like a loop gain curve ... Are you sure you followed erikl's
instruction ? Add an AC value of 1V to your supply and run an AC
simulation just as erikl proposed.
Maybe one addition to that. AC is always small-signal...
Looks ok to me, beside maybe the the input pair could use
some resizing for lower offset ;) It seems that your input pair
is close to moderate/stron inversion which is ok for high bandwidth
differential pairs. However you could place it in weak inversion for
lowest offset.
Is the cap at the...
And whats exactly the problem with the driver using more area then the
amplifier ? Sometimes it simply comes out that way. Don't be shy, just do
the layout. I know, it looks weird, but it's totally ok, as long as you meet your
spec, also in an RC-extracted simulation. For such a big driver it...
Interesting to hear. It seems that this topology is working
much better if I compare your 12% to my 25% solution
before trimming (even if I switch to 3sigma there is still
a difference). I persume you trim the current to bring
the delay on target right ?
Best Regards (aus München ;) )
Andi
Hi erikl
I have a question about the accuracy of the circuit you proposed.
How big is the spread of the delay if one considers a process spread
of +- 4.5sigma, temperatur -40 to 140, supply variation ?
I have used something similar in the past and the accuracy was not
very good, up to +-25%...
If you have a reliable clock available you can simply use a counter
to count clockcycles. Apart from that you can use a slowed down
inverterchain (loaded outputs or big length). This however yields
in slopes that are totally messed up so you need to reconstruct
proper slopes at the end of the...
I had a little time to think a little bit about a ASIC implemenation of a DRAM
Maybe it's a good idea to store the information in differential form, meaning
that you spend one extra bit to store the inverted info to a neighbouring cell.
When reading the info you connect the cell and the inverted...
Directly connecting metal to a weakly doped n or p area usually ends in
a schottky contact and not in an ohmic contact. Therefore a strongly
doped contact area is formed to reduce this effect.
Best Regards
Andi
Why not use the 'stem' command ?
Just use the vectors of x and t1 and type
stem(t1,x)
and you automatically get the plot of a time disrecte signal
that still has continous values.
Best Regards
Andi
Hi Johnny
Ok, thanks for the additional info. The fact that you'll build your storage array
with MOS-Caps makes life a lot easier ;)
Ok, first we sum up the leakage for a MOS-Cap that have an effect on cell
retention here. The most important ones here will be sub-vt leakage of the
select device...
Hi Johnny
First of all, I'll try to answer your simpler questions ;) I have sent you a PM
regarding some other stuff I need to know before going into more detail, as
I have noticed that my first try to give you an answer got more and more
complex ;)))
In general you need a spec, wherever this...
What about device reliability ? 7.5V for a 0.18um process looks
a little bit to high ... or do you use a high voltage process with
thicker oxids ???
Best Regards
Andi
I forgot one important point which has been implemented
in the latest DRAM designs. Shame on me. As most of the
leakage mechanisms strongly depend on temperature
a temperature dependand refresh is a good idea to
dynamically change the refresh rate. This is spec for DDR3
but I remember that we...
Hi there
In a real DRAM 1T1C design you will never have a leakage detection. You just
set the refreshtime according to the minimum spec or, if your process is better,
to a higher refresh time, as this saves a lot of power.
If you want to implement a leakage detection you first need to collect...
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