Question

I posted this problem 2 time and I got wrong answer. please solve and answer (explain from where you get the values) For a NMOS transistor sized (W/L) = (20 um/0.2 um) and biased with a fixed p = 0.5 mA, how much does the unity-gain frequency of the transistor, fr, change with a 5% decrease in Cox and a 10% decrease in un?

Answer 1

The unity-gain frequency of the transistor fr will decrease by 15% with a 5% decrease in Cox and a 10% decrease in un.

Step-by-step explanation:

Unity-gain frequency (fr) of a transistor is given by the formula:

fr = gm / (2π * Cox * un * (W/L))

where,

• gm is the transconductance of the transistor
• Cox is the oxide capacitance per unit area
• un is the mobility of the electrons in the channel
• (W/L) is the ratio of transistor width to length

Given the transistor size (W/L) = (20 um/0.2 um) and p = 0.5 mA, we need to find how fr changes with a 5% decrease in Cox and a 10% decrease in un.

Assuming gm is constant, a 5% decrease in Cox would cause a 5% decrease in fr, while a 10% decrease in un would cause a 10% decrease in fr. Therefore, the unity-gain frequency of the transistor fr would decrease by a total of 5% + 10% = 15%.