by Gregory Mirsky, Design Engineer, Deer Park, Ill., How2Power Today, Nov 14 2025
Focus:
The integrator design in a recent article was incomplete as it did not correct for the
“walkaway” of the integrator output caused by thermal and noise effects at the amplifier’s
inputs, which include input voltage offsets and leakage current. These stray parameters
make the integrator inoperable if specific measures are not taken. Very often designers
use a feedback resistor of a few megohms, establishing negative feedback to eliminate the
integrator output walkaway. But does this method work and if so, what effects might it
have on integrator operation? In this article, the author analyzes the impact of the dc
feedback resistor on integrator design—both inverting and non-inverting integrators. He
also recommends an alternative method of stabilizing integrator operation—using servo
feedback—and gives an example of its use in a Rogowski sensor application. This article is
a continuation of two previous series on designing Rogowski sensors and integrators.
What you’ll learn:
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