Module 4 : Propagation Delays in MOS
Lecture 16 : Propagation Delay Calculation of CMOS Inverter
 
16.2 Quick Estimates:
We will give an example of how to calculate quick estimate. From ffig 16.22, we can write following equations..
 
 
Fig 16.21: Example CMOS Inverter Circuit
  

From figure 16.21, when Vin = 0 the capacitor CL charges through the P-MOS, and when Vin = 5 the capacitor discharges through the N-MOS

. The capacitor current is -

Fig 16.22 : Propagation Delay of above

MOS Circuit
From this the delay times can be derived as  
The expressions for the propagation delays as denoted in the figure (16.22) can be easily seen to be
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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