lavpass

Lavpass is the term used in Swedish (and Norwegian) for a low-pass filter in electronics. A lavpass filter passes signals with frequencies below a chosen cutoff and attenuates higher-frequency components.

Key parameters are the cutoff frequency, the passband, the stopband, and the attenuation slope. For an n-th order filter, the roll-off is about 20n dB per decade beyond the cutoff. The magnitude response is near unity for frequencies well below fc and decreases at higher frequencies.

Implementations can be passive or active. Passive lavpasses include RC, RL, and LC networks; a first-order RC filter has fc = 1/(2πRC). Active lavpasses use operational amplifiers, with Sallen‑Key or multiple‑feedback topologies to provide higher-order filtering and gain.

Common applications include anti-aliasing and anti-imaging filters for analog-to-digital and digital-to-analog converters, audio crossovers, and smoothing of sensor or measurement signals.

Design considerations include component tolerances, source and load impedances, desired stopband attenuation, and the bandwidth of the chosen active devices. Higher-order filters offer sharper attenuation but can introduce phase shifts and require more careful layout.

In English, lavpass corresponds to a low-pass filter. The term appears in Scandinavian electronics literature and is commonly denoted as LPF or H(s) for the transfer function.