what is effective impedance?

[sina25]

What is effective impedance?

 

[Kral]

sina25,
Can you describe the context in which the phrase is used?
Regards,
Kral

 

[Kral]

sina25,
I means that the output resistance with feedback applied is greater than the output resistance of the device (FET) itself.
Regards,
Kral

 

[sina25]

I do not uderstand what you mean;
could you or anybody be more understandable, please?;

thanks

 

[Davood Amerion]

when feedback used in any circuits, there impedance changed. feedback can change impedance to higher or lower value depend on its usage.

 

[sina25]

How could i get the effective impedance from the reference to the ground node of this bandgap reference?; and how could i get the effective impedance from the reference to the input supply voltage of this bandgap reference?

Is exactly the effective impedance from the reference to the ground node R3, or is an approximation?


thanks

 

[vahidkh6222]

all i see from vref to ground is R3 in parallel with drains resistances(=0) mirror in the sourse.....so the Reff is 0!!!

 

[Davood Amerion]

Vref have [with good approximation] impedance of R3 ohm to ground.

 

[sina25]

How could i get the EXACT EFFECTIVE IMPEDANCE from the reference to the ground node of this bandgap reference?; and how could i get the EXACT EFFECTIVE IMPEDANCE from the reference to the input supply voltage of this bandgap reference?