low noise opamp circuit design

[xwcwc1234]

Hi all ,
I want to design a low-noise amplifier for microphone using 0.35um CMOS process , any one can provide me some information on this subject or reference papers ? Thanks.

 

[dynamicdude]

I think there is some good material in Baker Lee book for CMOS Circuit design.

 

[andy2000a]

Paul R gray / Meyere
analysis & design of analog IC

chap 11


active Load mos is M3 M4
input nmos ise M1 M2

1/f noise =>
2kp/(fW1L1Cox) * [1+ { ( kn *un* (L1)^2) / ( kp up (L3)^2) }
if L3> 3* L1 noise is small

Thermal_noise => 4Kt *4 /(3* (2up*Cow (W1/L1) *Id)^0.5 ) *
[ 1+ { ( un *(W3/L3)) /(up * (W1/L1) ) } ^0.5 ]
if W1/L1 > W3/L3 noise small

another parameter is mos input Rg (gate impedance) , even thou mos have very high impedance , but I forget equation about Rg

Added after 37 minutes:


for MOS outut noise

v^2 = (4KT Rg) /3 * [ (gm* ro )^2 ]

Rg is gate impedance , if mos gate impedance is large
thermal noise is Large


V^2 (flicker) = K / (Cox *W*L*f)

 

[sunking]

cmos analog circuit design
allen
chap 7

 

[xwcwc1234]

Thank you all above. But ifor microphone in circuit, what is the detail design spec. or what should I care about ?

 

[amic]

Thank you all above. But ifor microphone in circuit, what is the detail design spec. or what should I care about ?

For Microwave circuits you need to read about Friis Equation for Noise Figure to design LNA. A good referance would be David Pozars book.

Good Luck.