Electronics Handbook/Devices/Filter/Low-pass

Low-pass fILTER

A low-pass filter is an electronic device that has stable voltage that does not change over a range of low frequencies.

Configurations

Network LR Low-pass Filter

${\frac {V_{o}}{V_{i}}}={\frac {Z_{R}}{Z_{R}+Z_{L}}}={\frac {1}{1+j\omega T}}$

$T={\frac {L}{R}}$

$\omega _{o}={\frac {1}{T}}$

Net Work RC Low-pass Filter

${\frac {V_{o}}{V_{i}}}={\frac {Z_{C}}{Z_{R}+Z_{C}}}={\frac {1}{1+j\omega T}}$

T = RC

$\omega _{o}={\frac {1}{T}}$