This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

  • Resolved

OPA2211A noise calculation on datasheet

Intellectual 2090 points

Replies: 3

Views: 812

Hi,

I cannot understand the noise calculation of inverting gain configuration in page 16 and figure 47 of OPA2211A.

Why the current noise is just (In*Rs)2, but not multiply the noise gain looks like as in non-inverting gain configuration?

Thanks and best regards!

Iven

  • Ivan,

    This noise calculation shows the individual output noise contribution from each component in separate terms. Feedback forces current noise to flow only through R2 in contributing its output noise component. Assume that the op amp feedback holds 0V on the inverting input. The noise current cannot flow through R1. It must all flow through R2.

    I hope this is clear and helps your understanding.

    Regards, Bruce.

  • In reply to Bruce Trump:

    It's very helpful. Thanks very much.

  • In reply to Bruce Trump:

    Bruce,

    Thanks for your explanation, I got it now!

    Best regards, Iven.

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.