Tunable circuit for rotary position detection

An apparatus, comprising:

• a measurement circuit configured to determine and provide current and voltage signals, the current and voltage signals corresponding to rotational motion of a motor;
• and
• a tunable circuit coupled to the measurement circuit and configured to:
• receive the current and voltage signals;
• filter the current signal to provide a filtered current signal;
• determine an estimated rotational speed of the motor based on the current and voltage signals;
• determine a rotational speed of the motor based on the filtered current signal;
• determine a k factor of the filter according to the estimated rotational speed and the rotational speed;
• and
• tune the filter according to the estimated rotational speed and the k factor.

A method, comprising:

• receiving current and voltage signals;
• filtering, via a filter, the current signal to provide a filtered current signal;
• determining an estimated rotational speed based on the current and voltage signals;
• determining a rotational speed based on the filtered current signal;
• determining a k factor of the filter according to the estimated rotational speed and the rotational speed;
• and
• tuning the filter according to the estimated rotational speed and the k factor.