ELEC207 Linear Integrated Circuits

Transcription

1 University o Nizwa Faculty o Engineering and Architecture Electrical and omputer Engineering ELE07 Linear Integrated ircuits Week 8 Ate Abu alim Fall 05/06 0/5/05

2 FILTE A ilter is a device that passes electric signals o certain requencies or requency ranges while preventing the passage o others. ignals with mixed Frequencies FILTE INPUT OUTPUT 0/5/05

3 TYPE OF FILTE Low pass Filter A low pass ilter is a ilter that passes low requency signals and attenuates signals with requency higher than the cut o requency. igh pass Filter A high pass ilter is a ilter that passes high requency signals and attenuates signals with requency lower than the cut o requency. Band pass Filter A band-pass ilter is a device that passes requencies within a certain range and rejects attenuates requencies outside that range. Band stop or Band reject Filter A band-stop ilter or band-rejection ilter is a ilter that passes most requencies unaltered, but attenuates those in a speciic range to very low levels. It is the opposite o a band-pass ilter. A notch ilter is a band-stop ilter with a narrow stop band. All pass Filter An all-pass ilter is a signal processing ilter that passes all requencies equally in gain, but changes the phase relationship between various requencies. It does this by varying its phase shit as a unction o requency. 0/5/05 3

4 TYPE OF FILTE 0/5/05 4

5 LAIFIATION OF FILTE There are many dierent bases o classiying ilters. Based on the electronic components used to construct a ilter, it can be Passive ilter Active ilter PAIVE FILTE The passive ilters are the electronic ilters that are made only rom passive elements -- resistors, capacitors, inductors, and transormers. A passive ilter has guaranteed stability. First order Low pass Filter First order igh pass Filter 0/5/05 5

6 ATIVE FILTE The active ilters are the type o electronic ilters, that use one or more active components i.e. transistors, operational ampliiers etc, along with, elements. First order Low pass Filter First order igh pass Filter 0/5/05 6

7 0/5/05 7 ATIVE FILTE - First order Low pass Filter Z It is a single pole low pass ilter. As the requency o the input signal is increased above cut o requency ω c =/, its output decreases at a rate o -0dB /decade. Z i K K Z Z V V i in out. jw Parallel

8 First order Low pass Filter Frequency esponse 0/5/05 8

9 ATIVE FILTE - First order igh pass Filter Z Z K V V out in Z Z i K. It is a single pole high pass ilter. When the requency o the input signal is less than the cut o requency ω c =/, its output decreases at a rate o -0dB /decade. 0/5/05 9

10 First order igh pass Filter Frequency esponse 0/5/05 0

11 ATIVE FILTE - First order Band pass Filter A unity gain low pass ilter whose cut o requency is ω c upper cut o requency, the larger o the two cut o requencies. A unity gain high pass ilter whose cut o requency is ω c lower cut o requency, the smaller o the two cut o requencies. A gain component to provide the desired level o gain in the pass band. V i Low pass ilter igh pass ilter Inverting ampliier V o 0/5/05

12 0/5/05 ATIVE FILTE - First order Band pass Filter L L L L i i in out K K V V

13 First order Band pass Filter Frequency esponse 0/5/05 3

14 ATIVE FILTE - First order Band reject Filter A unity gain low pass ilter whose cut o requency is ω c Lower cut o requency, the smaller o the two cut o requencies. A unity gain high pass ilter whose cut o requency is ω c Upper cut o requency, the larger o the two cut o requencies. A gain component to provide the desired level o gain in the pass band. Low pass ilter V i igh pass ilter umming ampliier V o 0/5/05 4

15 0/5/05 5 ATIVE FILTE - First order Band reject Filter L L L L i i in out K K K V V

16 First order Band reject Filter Frequency esponse 0/5/05 6

17 0/5/05 7