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.

how to design a zero offset opamp?

Status
Not open for further replies.

leonken

Full Member level 3
Full Member level 3
Joined
Jun 12, 2004
Messages
169
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,296
Activity points
1,437
opamp offset compensation

how to design an opamp without offset?
thank you
 

offset opamp

First, you got to design a perfectly symetric opamp to eliminate systematic opamp that may exist in some architecture.

The remaining of, which is random offset, will vary infunction of your device's dimensions. So, you've got to have large transistors to significantly reduce offset, but be aware that an exact zero offset opamp is just not feasible. But with big transistors area, you may reduce bellow your desired offset value.

However, if you really need an extremely low offset voltage, some technics exists to compaste for the amplifier offset, which are namely the input offset compensation, and output offset compensation. Both consists in using capacitors to remove the offset voltage at the input (resp. output) of the amplifier.

These technics are described in Design Tech. for High Speed High Resolution Comparators - IEEE JSSC vol 27 n12, Dec 1992 by Behzad Razavi.

But, once again, even with these techniques, there will still remain a slight offset in you amplifier. Moreover, some time is necessary for the offset compensation to be carried out, when your amplifier won't be available for amplifiyin. And, last drwaback, some conditions are required on the amplifier to allow input/output offset compensation.
 
  • Like
Reactions: hurb

    hurb

    Points: 2
    Helpful Answer Positive Rating
opamp offset

There is no zero offset. Try chopper, auto zero, technique etc ....
 

op amp offset compensation

you can try CDS structure for the opa.
and the low offset opa is biplor
 

op amp offset

Hi Mline7,

Can you upload me the paper "Design Tech. for High Speed High Resolution Comparators - IEEE JSSC vol 27 n12, Dec 1992 by Behzad Razavi" as you mentioned in the forum.

Thanks,
Suria3
 

zero offset op amp

CDS means "correlated double sampling", a particular case of auto-zeroing(AZ)
 
  • Like
Reactions: hurb

    hurb

    Points: 2
    Helpful Answer Positive Rating
op-amp offset

about opa design

u could turn to Ti opamp.

where u would get the most detail analysis about opa
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top