MCH LC CHN DINhm thc hin:

H Vn Phng Ph QucTrn Hong NamV L Tn Quc

YU CU: Thit k b lc chn di: Chn tn s: 50HzBng chn: 3Hz suy hao: -30dbDBf3Hz-30db50Hz

Chn 2 m hnh mch chn di:

Lc chn di KRCLc p ng NOTCH

Thit k l thuyt cho mch KRC

Chn C =100nF => R=1/2fC =31.8 k =33k R1=R/2 = 15k Q= 1/(4-K) ! Ta mun Q ln dc ln. K= 1+ Rb/Ra=4 => chn Rb=10k,Ra = 3.3k.

Mch lc chn di KRCS nguyn l:

M PHNG

Thit k l thuyt cho mch p ng Notch

Mch chn di c p ng NOTCHS nguyn l:

M PHNG

O THC TMCH NOTCH

Vin=2Vp-pMch lc chn di NOTCH:

Mch lc chn di NOTCH:f=15HZ, V=0.9V

Mch lc chn di NOTCH:

F=30Hz, Vout=0.9V

F=40HzVout=0.5VMch lc chn di NOTCH:

F=45H, Vout=0.25VMch lc chn di NOTCH:

F=48Hz, Vout=0.15VMch lc chn di NOTCH:

F=50Hz, Vout=0.25VMch lc chn di NOTCH:

F=60Hz Vout=0.6VMch lc chn di NOTCH:

F=70HzVout=0.8VMch lc chn di NOTCH:

Mch lc chn di NOTCH

F=75HzVout=0.85V

Mch lc chn di KRC

Mch lc chn di KRC

Mch lc chn di KRC

Mch lc chn di NOTCH

suy hao:Bng chn:Tn s chn: 48HzKhng tha yu cu!

fHz153040454850607080Vout(V)0.90.90.50.250.150.250.60.90.9

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