Electronics Fundamentals/Electronic Filter/Band Pass Filter

LR + CR Band Pass Filter

Characteristics

${\frac {V_{o}}{V_{i}}}=({\frac {1}{1+j\omega {\frac {L}{R}}}})({\frac {j\omega RC}{1+j\omega RC}})$

Band Pass or band of frequencies that has a stable voltage over a band of frequencies

${\frac {R}{L}}-{\frac {1}{RC}}$

Provided that

${\frac {1}{RC}}>{\frac {R}{L}}$

RC + RL Band Pass Filter

Characteristics

${\frac {V_{o}}{V_{i}}}=({\frac {1}{1+j\omega RC}})({\frac {j\omega {\frac {R}{L}}}{1+j\omega {\frac {R}{L}}}})$

Band Pass or band of frequencies that has a stable voltage

${\frac {1}{RC}}-{\frac {R}{L}}$

Provided that

${\frac {R}{L}}>{\frac {1}{RC}}$

Summary

Band Pass Filter has stable voltage over a band of frequencies

${\frac {R}{L}}-{\frac {1}{RC}}$

Provided that ${\frac {1}{RC}}>{\frac {R}{L}}$ for the LR + CR configuration

${\frac {1}{RC}}-{\frac {R}{L}}$

Provided that . ${\frac {R}{L}}>{\frac {1}{RC}}$ for the CR + LR + configuration