The structure doesn't really speak to me in terms of
circuit function, but I'd guess there is one given that
the poly is broken up.
I see what looks like a source finger that feeds two
drains, each also fed by another source and so on.
So I'd call a unit drain current at the root of the
source stripe, unidirectional, defined by some load
of your estimation.
Current enters at the root and the first contact
sidewall is your probable choke-point. You would
apply a construction-analysis-based, worst cased
cross section at that point (A). Then your knowledge
of the load, and the duty factor at which you throw
that current, would give you I for purposes of Javg.
You probably ought to accommodate the reality that
finger current distribution has some nonuniformity, but
I don't often see this done. At any rate if you only have
the aggregate output current, then you'd apportion it
between fingers using your best judgment or data.
Now I understand why that the current is highest on that one finger. This is due to sharing of the M1 middle finger on the input inverter. Great explanation indeed.
So in my end, the solution to resolve that high current density issue on that M1 is to increase the width of that affected M1, right?
About the current distribution on the second inverter, it seems that they have "equal" current flowing on each of the M1 finger. I noticed also that the VIA of M2 to M3 (pink small squares) covered the second inverter area and none on the input inverter. If I have to add that VIA on the input inverter side, is it possible that the current at each M1 inverter finger will also become "uniform" ?
By the way, the conditions is frequency 400MHz at 125°C (dynamic power analysis).
Why there is no current / power in the drains of NMOS and PMOS, and no current/power in the source of NMOS on your plots?
Are they not conducting current?
Thanks for the explanation.
What do those diamond-shaped markers mean? Does their color correspond to the current in the devices, on in M1 lines?
Due to distributed effects (complex connections between metal layers), current density in the metals / vias is highly non-uniform - is this non-uniformity taken into account somehow in this analysis?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?