Chopper Op Amps—an inside look

This page provides supplemental information for the blog, “Chopper Op Amps and Noise.”

The Powerpoint presentation (link below) reviews much of the basic theory of choppers, including a discussion of the noise/power advantage of chopping compared to auto-zero techniques.  It is annotated with informative speaker notes.

 0143.Micropower Chopper Op Amp.pdf

Sorry, but we cannot provide the original IEEE paper on our site but here is a link where it can be obtained:

A Micropower Chopper-Stabilized Operational Amplifier Using a SC Notch Filter With Synchronous Integration Inside the Continuous-Time Signal Path

Here are links to information on some example chopper op amps that use these techniques:

  • OPA333   Micropower (35uA) chopper op amp
  • OPA378   900kHz GBW chopper op amp
  • OPA188   36V precision chopper op amp