Wilson current mirror problem

Thread Starter

OggiSerbia

Joined Dec 28, 2017
34
I have an easy Wilson current mirror problem to solve. I tried to do it but I am not sure if it is correct.
Here is the circuit:
Screenshot_2.jpg

The problem is to find (Ir/I), i.e. Currence Ir over currence I. It is assumed that all the transistors are equal: beta (currence amplification) is the same.
Here is my solution:

Image No.1:
Screenshot_2 - Copy.jpg
Image No.2:
zad1.jpg
Image No.3:
zad2.jpg
 

danadak

Joined Mar 10, 2018
3,682
Q3, Q4 scaling the output current by 2 ? Assuming they are interdigitated match
pair geometry. Or splitting current to reduce T effects ?

Or eliminating CM effects of source I source ? Or eliminating output supply
effect on output current due to finite output sink. To raise effective complience
of mirror and increase finite dynamic R of output transistor ? The analysis
should lead to answer.

Guess on my part.

Regards, Dana.
 
Last edited:

MrAl

Joined Jun 17, 2014
6,785
I have an easy Wilson current mirror problem to solve. I tried to do it but I am not sure if it is correct.
Here is the circuit:
View attachment 155338

The problem is to find (Ir/I), i.e. Currence Ir over currence I. It is assumed that all the transistors are equal: beta (currence amplification) is the same.
Here is my solution:

Image No.1:
View attachment 155339
Image No.2:
View attachment 155341
Image No.3:
View attachment 155340

Hello there,

I used a different approach by substituting an equivalent topology so i could write the equations more directly and got the same result. So you must have done something right :)

CurrentMirror-5.gif
 
Last edited:
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