Filters¶
The Nyquist-Shannon sampling theorem states that a continuous-time signal can be accurately reconstructed from its samples if it is sampled at a rate at least twice its highest frequency.
A switched capacitor filter uses capacitors and electronic switches to emulate resistors, providing precise filtering without relying on physical resistor values.
A high pass filter allows signals with frequencies higher than a specified cutoff frequency to pass while attenuating lower frequencies.
State variable filters are active filters that provide simultaneous low-pass, high-pass, and band-pass outputs using multiple integrator stages.
Butterworth and Chebyshev filters are widely used analog filter designs. Butterworth offers a flat passband response with a slow roll-off, while Chebyshev achieves sharper roll-off by allowing controlled ripple in the passband.
Bandstop filters block a specific range of frequencies while passing others. A notch filter is a special type with a very narrow stopband, ideal for removing unwanted tones.
A low pass filter allows signals with frequencies below a certain cutoff to pass while attenuating higher-frequency signals.
A Sallen-Key filter is an active filter configuration using an op-amp along with resistors and capacitors to achieve low-pass, high-pass, or band-pass responses.
Analog filters process continuous-time signals to allow certain frequencies to pass while attenuating others, shaping the signal in the frequency domain.
