Hi all, this is my first post here. I'm hoping some input will help me verify what I am missing.(adsbygoogle = window.adsbygoogle || []).push({});

This is a question from an exam paper I'm doing for a module on introduction to semiconductor technology

Calculate the CMOS inverter output voltage Vout, and the corresponding inverter current,

for each of the following inverter input voltages:

Vin = 1V

Vin = 4V

Vin = Vout = Vinv (inverter switching voltage)

where the CMOS transistor parameters are as follows:

Vthpd= -Vthpu=0.7V, Wpd/Lpd=2, Wpu/Lpu=4, μn=2μp, Vdd=3.5V

Clearly state (and verify) all assumptions.

The issue is less with the question, more with the sample solution that the lecturer has given, where he provides some assumptions, which has confused my previous understanding:

Assume Vdspd ~ .3V, Vdspu = .3-3.5 = -3.2V

Vdsatpd = Vgspd-Vthpd = 2.1 - .7 = 1.4 => in linear operation (to be verified after calculation)

Vdsatpu = Vgspu-Vthpu = 2.1-3.5+.7 = -.7 => in satn operation (to be verified after calculation)

I'm confused as to where he obtained the value '2.1'. I understand everything else with regards to equating the linear or saturated I-V MOSFET equations and proceeding from there, but I think I'm missing something rather basic here... go easy lol....

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Semiconductor Voltage Output

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**