Help on biasing transistor

[ricopt]

Can someone guide me how to bias my MN2 to saturation mode ?
which component value i need to change ?
Which component will affect the operation mode of MN2 ?

Your reply will be greatly appreciated.
Thank you

 

[rajanarender_suram]

the current in MN1 & the resistor R2 will decide the operating point of MN2

 

[ricopt]

any more detail steps ?
my R2 should be as high as possible
to reduce noise
how the R2 affect ?
how i control the current in MN1 ?

 

[checkmate]

What makes you think that large resistors give noise reduction?

 

[ricopt]

i think is not noise
is attenuation voltage drop
still no one can answer my question......

 

[pavel_adameyko]

Hello
Try the following circuitry

You can scale transistors and resistors in auxiliary amplifier and main amplifier as 1:10, for example.

 

[ricopt]

Hello
Try the following circuitry

You can scale transistors and resistors in auxiliary amplifier and main amplifier as 1:10, for example.

bro, thx, but, i am using 0.18um technology
so my L have to be minimum as 0.18um

 

[pavel_adameyko]

so my L have to be minimum as 0.18um

I think, this schematic would work in any technology - i used 0.35 um just for example.
You should choose width (and length) of transistors and value for resistors from noise, gain, current consumption requirements and so on. The general principle of this circuit is in using auxiliary amplifier which is replica of main circuit. Transistors of auxiliary amplifier would have almost the same operation points as those in main. From power management point you can reduce width of transistors in bias circuit (and accordingly, increase value of resistors) as, for example 1:10, so current in auxiliary amplifier would be 10 times lower than in main.