how to design current sink amplifier?????

[wael_wael]

hi
in fact i am face problem that is how to find the sizes of transistors for cureent sink op-amp, how to find the length of channel.
could some one help me to resize the op amp
regards

 

[A.Anand Srinivasan]

it is based on your specifications... it is hard to say without the clear picture of the spec and the design configuration that you have selected.... but smaller the length then more probs are to be encountered....

 

[wael_wael]

it is based on your specifications... it is hard to say without the clear picture of the spec and the design configuration that you have selected.... but smaller the length then more probs are to be encountered....

I WANT USE IT FOR GAIN BOOSTING OP AMP, 12 db, 200MHz unity gain frequency
thanx

 

[A.Anand Srinivasan]

since you are using a gain boosting opamp configuration it already takes care that the current sinking capability is high... as far as length is concerned reducing the length may aid in increasing current sinking but only to a certain limit due to velocity saturation of electron... so it just the selection of the optimum value found by simulation....