Amplifier design with given specifications

[Nirajks]

I tried to design an amplifier with following specification:
supply voltage 1.8-5.5
voltage gain 1-1000
power dissipation <0.25mW
Bandwidth at gain of 10 is 35 kHz

Since, I am new in field of Analog design so I have tried to design it using single stage opamp. but I got an undesired value of aspect ratio.can anyone help me out or suggest me some where I can get the procedure of amplifier design. its urgent.

 

[KlausST]

Hi,

Show what you have done so far.

Klaus

 

[Audioguru]

An opamp has 3 stages, not just one:
1) Input differential stage
2) Gain stage
3) Output stage.

 

[Nirajks]

Sir, i am sending snapshot of Diffamp Model.when I am calculating gm for NM1 by using specifications I am getting very low value, because the spcified GBW is in KHZ.the Example which i have followed for the Design had GBW in MHz.I am providing the URL of my Screenshot.kindly help me out.

 

[d123]

Hi,

I still work with discrete components, but if it helps, and you haven't seen them before, try looking at any analog design book, there are hundreds of books and papers freely available online e.g. Analog Design Essentials by W. Sansen and also CMOS_Circuit_Design__Layout__and_Simulation__3rd_Edition are two examples.

I don't know, but a one-stage op amp looks sooo suspect, I can't get one to work and be any practical use, discrete design or CMOS like yours - as stated above, op amps that work are a diff pair, gain stage(s) and output stage afaik.

 

[Audioguru]

Are you learning about designing an IC opamp made with Cmos? Didn't your teacher teach it to you? Don't you have a text book about it?

 

[d123]

a one-stage op amp

two-stage, two-stage... like your design.