VLSI CMOS - Layout to Schematic help!

Thread Starter

Geza

Joined May 18, 2009
7
thanks for your quick response :) I haven't been given a map for them, is it possible to guess which pattern is the n-type substrate which is metal 1 ... etc etc from the way it is drawn?

Cheers
 

Greg_R

Joined May 5, 2009
11
Yes, you can guess based on how the structures are drawn. The "legs" crossing the substrate are going to be either poly or M1. A poly between two metal legs = a transistor. Typically, for basic diagrams PMOS devices are drawn above NMOS devices (you'll see the two rows of diffusion in each problem). In the circuits without wire labels (VCC/VSS, cat, dog, etc.), start assigning arbitrary labels to keep things straight as you create the schematic. The thick horizontal wires in #2&3 are VCC (top) and VSS (bottom). Be careful though, I'm not sure if your prof wants you to guess at those labels or not.

Note: the first diagram is evidently all NMOS devices...
 
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