The configuring of a micromirror to suppress a resonance of the micromirror. As part of the configuring process, the micromirror is subjected to multiple actuation frequencies, and the micromirror response is measured in response to at least some of these actuation frequencies. A resonant frequency of the micromirror is then determined using at least some of the measured mechanical responses. Then, depending on this determined resonant frequency of the micromirror, notch filter parameters are selected. There is more than one possibility for notch filter parameters, where the selected possibility depends on the determined resonant frequency. The notch filter is then configured with the selected notch filter parameters.

A motor control apparatus includes: an oscillation instruction unit outputting an oscillation instruction signal; a filter unit performing filtering processing having frequency characteristic defined by a filter parameter; an oscillation forcing unit configuring a control loop in an oscillation period together with the filter unit, a current control unit, a motor, and a velocity calculation unit and causing the control loop to oscillate during the oscillation period in which the oscillation instruction signal is in the on-state; an amplitude evaluation unit acquiring, as an evaluation value, the amplitude ratio of an input signal to an output signal of the oscillation forcing unit when the control loop oscillates; and a filter adjustment unit comparing evaluation values provided when filter parameter candidates are set in the filter unit sequentially, selecting one of the filter parameters achieving a smaller evaluation value, and setting the selected filter parameter in the filter unit.

A method for compensating the bandedge ripple of an analog filter, using a circuit comprising a low pass filter is described. The method comprises receiving, at the analog filter, a plurality of tones of different frequencies from a tone generator, measuring, an amplitude of each tone in the plurality of tones after each tone is processed by the analog filter, storing the measured amplitudes and frequencies in a database, measuring a bandedge ripple by measuring a difference in amplitude between a first tone and a second tone from the plurality of tones, and selecting a low pass filter, from a plurality of low pass filters, based on the measured difference.

To suppress an unstable operation of a device caused by filtering, an output selection unit is configured to acquire an unfiltered value representing an input signal (signal before filtering) stored in an input holding unit, a filtered value representing a signal acquired by filtering the input signal by a filtering unit, and a previous output value representing an output signal output at a previous time, select a middle value out of the filtered value, the unfiltered value, and the previous output value, and set the selected middle value as a current output value of an output signal.

In one embodiment an adaptive filter structure comprises a detector circuit (10) configured to receive an input signal (Sin), to detect a presence of a sweeping interference in the input signal, and upon detection of such sweeping interference to provide a first trigger signal (T1) to a delay circuit (20), wherein the first trigger signal (T1) comprises a first frequency indication (f1); the delay circuit (20) is configured, upon receiving the first trigger signal (T1), to provide a second trigger signal (T2) to a tracker circuit (30) after an adjustable amount of time; the tracker circuit (30) is configured, upon receiving the second trigger signal (T2), to estimate a frequency of the sweeping interference using a second frequency indication (f2), to track the estimated frequency and provide the estimated frequency as a third frequency indication (13) to a notch filter circuit (40); and the notch filter circuit (40) is configured to substantially eliminate the sweeping interference from the input signal (Sin) using the third frequency indication (f3) and therefrom provide an output signal (Sout).

A motor control apparatus includes: an oscillation instruction unit outputting an oscillation instruction signal; a filter unit performing filtering processing having frequency characteristic defined by a filter parameter; an oscillation forcing unit configuring a control loop in an oscillation period together with the filter unit, a current control unit, a motor, and a velocity calculation unit and causing the control loop to oscillate during the oscillation period in which the oscillation instruction signal is in the on-state; an amplitude evaluation unit acquiring, as an evaluation value, the amplitude ratio of an input signal to an output signal of the oscillation forcing unit when the control loop oscillates; and a filter adjustment unit comparing evaluation values provided when filter parameter candidates are set in the filter unit sequentially, selecting one of the filter parameters achieving a smaller evaluation value, and setting the selected filter parameter in the filter unit.

To suppress an unstable operation of a device caused by filtering, an output selection unit is configured to acquire an unfiltered value representing an input signal (signal before filtering) stored in an input holding unit, a filtered value representing a signal acquired by filtering the input signal by a filtering unit, and a previous output value representing an output signal output at a previous time, select a middle value out of the filtered value, the unfiltered value, and the previous output value, and set the selected middle value as a current output value of an output signal.

A low drop-out (LDO) regulator includes an NMOS transistor having one of a source and drain terminal configured to be coupled to a voltage supply and the other of the source and drain terminal coupled to the low drop out voltage regulator output. A gate driver for the LDO regulator includes a boost converter having a boost converter input configured to be coupled to a boost converter reference voltage, a boost converter output configured to output a boosted voltage greater than the boost converter reference voltage and the voltage supply; and a boost converter clock input configured to receive a clock signal. The gate driver further includes a notch filter having a notch filter input coupled to the boost converter output and a notch filter output coupled to the gate driver output.