Band-pass filter

1. Passive band-pass filter:

The LC is connected in parallel. When the frequency is low, the capacitance is high, the inductance is applied, and the output voltage Vo is very small.

When the frequency is high, the inductance is high, the capacitance is used, and the output vo is very small.

The frequency is not small, and the resistance is equivalent to the sensitivity,

(The content is equal to the value of the content)

At this time, the capacitance is equivalent to the inductance current, but the phase is opposite and offset each other. The effect impedance of LC parallel operation is great, and the voltage Vo is great.

 

2. Active band-pass filter:

Active Filter can highlight useful frequency signals, attenuation of useless frequency signals, and suppress interference and noise.

Example 1:

Example 2:

 

Band-pass filter