Abstract
In negative-feedback amplifier design, electromagnetic interference (EMI) behavior is usually completely disregarded. EMI can, e.g., result in detection of low-frequency envelope variations of the usually high-frequency interfering signals. If the detected signals end up in the pass band of the negative-feedback amplifier, they cannot be distinguished from the intended signal any longer, so the signal-to-error ratio (SER) is reduced. Several measures can be taken to prevent unacceptable reduction of the SER, like applying filters, chokes, etc. In this paper, however, circuit design aspects are investigated. It is assumed that interference reaches the amplifier input and that the SER has to be assured by a proper design of the negative-feedback amplifier. Since EMI is related to nonlinear distortion, it is a function of the loop gain of the negative-feedback amplifier. For a given electromagnetic (EM) environment it is therefore possible to calculate the minimum loop gain required to reduce EMI to acceptable levels without filtering. To illustrate this systematic design method a transimpedance amplifier is designed and built to properly function in interfering field strengths up to 30 V/m. Experimental results are in good agreement with theory.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: IEEE Transactions on Circuits and Systems I: Regular Papers
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.