CMOS Resistance: Drawing NAND & Solutions

  • Thread starter Thread starter nobrainer612
  • Start date Start date
  • Tags Tags
    Cmos Resistance
AI Thread Summary
The discussion centers on calculating the resistance in a CMOS NAND gate under different input conditions. When both inputs A and B are high, the total resistance is the sum of the NMOS resistances, Rn + Rn. If both inputs are low, the PMOS resistances are in parallel, resulting in Rp*Rp/(Rp + Rp), which simplifies to Rp/2. When A is high and B is low, the output is VDD, and the resistance is determined to be Rp. The participants confirm these assumptions and calculations regarding the resistance values for various input states.
nobrainer612
Messages
24
Reaction score
0

Homework Statement



I drew a NAND in the picture.

302tlld.jpg




The Attempt at a Solution



I know when A and B are both high ( value 1), resistance will be Rn + Rn because those 2 NMOS will be turned on and resistance will added up since they are in series.

Also when A and B are both low ( value 0), both PMOS will be turned on. My first question is, 1.) is the resistance become Rp*Rp/(Rp + Rp) because they are in parallel?

My second question is, if A is high (value 1) and B is low ( value 0) , output should be VDD ( value 1). But what will be resistance be? I think they are neither in series nor parallel. So will the resistance only become Rp ?

Hope somebody can share their ideas. Thank you
 
Physics news on Phys.org
nobrainer612 said:
I know when A and B are both high ( value 1), resistance will be Rn + Rn because those 2 NMOS will be turned on and resistance will added up since they are in series.

Also when A and B are both low ( value 0), both PMOS will be turned on. My first question is, 1.) is the resistance become Rp*Rp/(Rp + Rp) because they are in parallel?

My second question is, if A is high (value 1) and B is low ( value 0) , output should be VDD ( value 1). But what will be resistance be? I think they are neither in series nor parallel. So will the resistance only become Rp ?

Hope somebody can share their ideas. Thank you
Hi nobrainer612! Those would be my answers, too.

Can you simplify this expression: Rp*Rp/(Rp + Rp) :wink:
 
sorry but I don't get what you mean.

Can you tell me if those I assumed are correct? because I am interested what the resistance is .

simplify this expression: Rp*Rp/(Rp + Rp) : isn't that equal (Rp^2) / 2*Rp = Rp/2?


So what I assumed:

if A is high (value 1) and B is low ( value 0) -----> resistance = Rp only? :bugeye:
Also when A and B are both low ( value 0) -----> resistance = Rp/2 ? :shy:
 
Last edited:
nobrainer612 said:
if A is high (value 1) and B is low ( value 0) -----> resistance = Rp only? ✔[/size][/color]
Also when A and B are both low ( value 0) -----> resistance = Rp/2? ✔[/size][/color]
:smile:
 

Similar threads

Replies
2
Views
3K
Replies
1
Views
1K
Replies
3
Views
1K
Replies
14
Views
5K
Replies
4
Views
10K
Replies
4
Views
4K
Replies
2
Views
3K
Back
Top