How do I minmise the Vgs drop across the Mosfet?

[ug02048]

vgs drop

I wanted to build a unity gain buffer. Any help is appreciated.

 

[cetc1525]

sooch cascode

use a cascode structure,the different w/l& you can reduce the vgs.

 

[eda4you]

sooch current mirror

Look for the Sooch cascode!

 

[konqueror]

sooch bias

what is a sooch cascode ? can you explain it in detail because i have never heard of it before

 

[twonsr]

sooch mos cascode current mirror

gray's book

page 271

 

[rongli]

mosfet vgs drop

can you upload a picture?

 

[eda4you]

drop across the mosfet when it is on

Here is a picture of it. There exists also a good IEEE-paper from sooch describing this circuit.

 

[ug02048]

Can you explain how it works? many thanks in advance..

 

[eda4you]

Look for the Gray's Book p. 271 (perfectly explained) or the paten of Sooch:

N.S. Sooch "MOS Cascode Current Mirror" U.S. Patent 4,550,284 October 1985.
(look for a patent server)

 

[lastdance]

I was never in favor of using this current mirror.
Much of the accuracy stemmed from accurate modelling. The circuit tries to bias the lower n-channels just enough for them to breath. this posed a great danger, any mishap can tipped u over into the triode. ur accuracy could suffer...
ur design need to be as free of modelling as possible