Subject: Basic VLSI Design

Topic: MOSFET Inverters

Difficulty: High

Here Kn ≠ Kp

|VT0, n| ≠ |VT0,p|

Therefore, this is an Asymmetric Inverter.

$k_R$ = 2.5 …..given

Step 1: Find VOH

VOH = VDD = 3.3 V

Since Vin = 0 ….. (nMOS – Cutoff, pMOS - conducting)

Therefore, Vout = VOH = VDD = 3.3 V

Step 2: Find VOL

Since, Vin = VDD = 3.3 V

pMOS is in cutoff and nMOS is conducting

Vout = VOL = 0 V

Step 3: Find VIL

When Vin = VIL

nMOS (saturation) = pMOS (linear)

Step 4: Find VIH

When Vin = VIH

nMOS (Linear) = pMOS (saturation)

Step 5: Noise margins

High noise margin = $NM_H$ = VOH – VIH = 1.75 V

Low noise margin = $NM_L$ = VIL – VOL = 1.08 V