Abstract: Systems and methods for dynamically adjusting an output driver are invented and disclosed. One embodiment comprises receiving a first signal. Applying the first signal to a first tuning element to generate a reference signal. Receiving a second signal. Applying the second signal to a second tuning element to generate a test signal, wherein the second tuning element is configured similarly to the first tuning element. Sampling the reference signal to generate a time-sampled reference signal. Sampling the test signal to generate a time-sampled test signal. Integrating the time-sampled reference signal and the time-sampled test signal to generate an error signal. Then, applying the error signal to adjust an output driver.

Abstract: An n-around nuller in a disk drive track-follow loop servo system is optimized by maximizing its feedforward orthogonality (channel separation). Sine and cosine terms (signals) are injected into the track-follow loop, thereby creating the separate channels (signals), to reduce the amplitude of the n-around component. The Fourier sum is then taken in connection with a phase delay variable and integrated to produce the proper feedback for maximizing orthogonality and minimizing instability. Specifically, the feedforward cosine term is low-pass filtered to find its average value. A step is then fed into the feedforward sine term and the response of feedforward cosine is observed. Feedforward cosine is then integrated to evaluate how much "cross talk" there is between the two channels. Once the integral sum is found, it is used as a feedback element for tuning the sine and cosine terms injected into the channels, thereby maximizing feedforward orthogonality and minimizing servo system nuller instability.