The Designer's Guide Community
Forum
Models in Minutes
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines. Sep 18th, 2018, 6:26pm
  HomeHelpSearchLoginRegisterPM to admin  
 
Pages: 1
Send Topic Print
Why do we need CDS, not only use auto-zero instead? (Read 381 times)
Jacki
Senior Member
****
Offline



Posts: 202

Why do we need CDS, not only use auto-zero instead?
Feb 28th, 2018, 11:42pm
 
Hello,

   Recently I recall the definition of correlated double sampling and auto-zeroing, i find it is not necessary to use CDS, we can just use auto-zeroing instead. Here we don't discuss the chopping.
   For example, in the switched-capacitor amplifier, we can use capacitive reset instead of opamp reset to achieve the auto-zeroing. But if we want to use the CDS, we have to either add more capacitors or change the switching solution (for example the CDS integrator).
   My first question is now that we can use auto-zeroing to achieve the offset cancellation, why we need CDS?
   My second question is when we use CDS, the opamp should have lower thermal noise, why? If the CDS is normally used in oversampling, maybe it is better for the fast response at the output than auto-zeroing.
   Any comments? Correction? Thank you very much.
Back to top
 
 
View Profile   IP Logged
Jacki
Senior Member
****
Offline



Posts: 202

Re: Why do we need CDS, not only use auto-zero instead?
Reply #1 - Mar 11th, 2018, 5:26am
 
Can we say CDS is used for high-speed application compared with auto-zeroing?
Back to top
 
 
View Profile   IP Logged
Pages: 1
Send Topic Print
Trouble viewing this site? Copyright © 2002-2018 Designer's Guide Consulting. 'Designer's Guide' is a registered trademark of Designer's Guide LLC. All rights reserved.

Our colleges are not as safe as they seem. Sexual assault is pervasive and the treatment of the victim by the adminstration is often as damaging as the assault: Campus Survivors, Campus Survivors Forum.

Some of our other sites that you might find useful: Avendesora, Inform and QuantiPhy.