CMOS inverter

[qaisarpk1]

NMOS PASSES LOGIC '0' STRONGLY BUT WEAK LOGIC '1'
PMOS PASSES LOGIC '1' STRONGLY BUT WEAK LOGIC '0'.?
what is the reason???

[reachrkata]

NMOS logic uses a MOSFET connected to GND (Logic 0). When the MOSFET is activated it acts almost like a short thereby bringing the signal to GND (logic 0) very well. On the other hand, for Logic 1 output the MOSFET is turned off, whereby the strength depends on how strong or weak the pull-up is.

The viceversa applies for PMOS.

Thats the reason why CMOS can give both a strong 1 and a strong 0, because it has both the MOSFETs.

-Karthik