Falling delay inverters VLSI CMOS

cmosdelayintegrated-circuitinvertervlsi

How do I obtain the falling delay driving by signal A:

Data:

NMOS W/L=1/.35

PMOS W/L=2/.35

Resistor-NMOS= 1/2 and PMOS5 Kohms.micro 

Cgate=Cdif=4/3fF/microm

Cmetal-ground=100fF

Cmetal-metal=39fF

Rmetal 800 ohms

1.-When B is not switching

2,-When B is switching simultaneously in the same direction than A

3.-When B is switching simultaneously opposite to A
circuit delay

Best Answer

If I understand correctly your aim is to have falling slope of inverters appear later than rising slope? If so, if it is available reduce W/L ratio of NMOS transistor and increase W/L ratio of PMOS transistor.

Capacitances on the output are seen both by NMOS and PMOS transistors.