Electronics Handbook/Devices/Filter/High Pass Filter

CR

Configuration

Characteristics

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

$T=RC$

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

RL

Characteristics

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

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

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

Summary

The two configurations above can be used for Low Pass Filter which has stable voltage which does not change with frequency over high range of frequencies