Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

how to obtain good PSRR for two stage amplifier?

Status
Not open for further replies.
A

alicia8283

Junior Member level 2
Junior Member level 2
Joined
Mar 3, 2005
Messages
21
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,283
Activity points
1,436
ahuja psrr

how to obtain good PSRR for two stage amplifier?
My stability is ok as i have put compensation cap at the 2nd stage..
thanks in advance..
 

psrr 2 stage

alicia8283 said:
how to obtain good PSRR for two stage amplifier?
My stability is ok as i have put compensation cap at the 2nd stage..
thanks in advance..
Click to expand...

a paper has explained it.
<<design techniques for cascoded cmos op amps with improved psrr and common-mode input range>> by david b.ribner & miles a.copeland
 
psrr + two stage

Increasing the channel length of your second stage amplifying transistor will help you get bigger positive PSRR. You can check Allen's book on this issue
 

Poor PSRR of the basic two stage op-amp can be attributed to the compensation capacitor.

Alternative compensation techniques such as Ahuja Compensation and Cascoded Miller Compensation will help achieve better PSRR performence at high frequencies.

I hope it helps.

With Regards
Sachin
 

When using a class A output, use an nmos driver with a pmos output. This isn't noticeable in AC sim, because of the small signal linearization, but for transient PSRR simulations (takes a lot of time, but these include the non-linearities of the transistors)
this is clearly visible.

2nd tip is isolating your opamp from the supply, by
-cascoding
-using a extra regulator which supplies your opamp. This can easily boost your PSRR by 30..50 dB.

br, Jef
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top