Difference between hand analysis and simulator results ?

[hoo]

Hi , I tried to design common source amplifier by hand analysis and obtained certain values of circuit parameter , then put these parameters into cadence simulator , after simulation I noticed that there is a big difference between the results obtained from hand analysis and others obtained from cadence simulator , what is the problem and how to solve it ?

 

[crutschow]

Generally the simulator uses more complex and accurate equations to determine the circuit operation so it is likely more accurate than your hand calculation. If you post your results for both I can perhaps comment further.