Whats the formula to calculate the resonance bandwidth?

[piggsypig]

Oscillator

Does anyone knows the formula to calculat the resonance bandwidth ? Pls Help :roll:

 

[mazelk]

Re: Oscillator

Hi...

The resonance frequency can be calculate by the inductance and capacitance across the signal node. Generally, this frequency can be get by w=sqrt(1/LC). If you ask about a resonance bandwith, maybe you refer to a band pass filter. Actually, an oscillator can be consider as a band pass filter with positive feedback.....

 

[piggsypig]

Re: Oscillator

Thanx!!!!
but is that formula applicable to both parallel and series circuits ? :?:

 

[mazelk]

Re: Oscillator

This is the general formula. You must get the equivalent parallel circuit (or equivalent capcitances and inductances) betwen those nodes.

 

[batdin]

Re: Oscillator

Bandwidth=f_resonance/Quality

For series LCR:
Quality=sqrt(L/C)/R_series

For parallel LCG:
Quality=1/(sqrt(L/C)*G_parallel) where G_parallel=1/R_parallel

 

[jetset]

Re: Oscillator

You can also plot it on a simulation software and get the f3dBHigh and f3dBLow, to get the band width BW = f3dBHigh - f3dBLow. Remember that your reference fequency is the one at which the output of the filter has the maximun amplitude.