Category: Filters

Second Order High Pass Butterworth Filter Derivation

Second Order High Pass Butterworth Filter Derivation: As in the case of a first order filter, a second order high pass filter can be formed from a second order low pass filter by simply interchanging the fre­quency determining resistance and capacitor. Figure 15.13 (a) shows a Second Order High Pass Butterworth Filter Derivation. The voltage […]

First Order High Pass Butterworth Filter Derivation

First Order High Pass Butterworth Filter Derivation: First Order High Pass Butterworth Filter Derivation – High pass filters are often formed by interchanging frequency determining resistors and capacitors in a low pass filter. A first order high pass filter is formed from a first order low pass type by interchanging components R and C. Figure […]

Second Order Low Pass Butterworth Filter Derivation

Second Order Low Pass Butterworth Filter Derivation: A stop band response having a 40 db/decade roll off is obtained with a Second Order Low Pass Butterworth Filter Derivation A second order filter can be obtained by coupling two active filters having a — 20 db/decade roll off to produce a roll off of — 40 […]

Basic Low Pass Filter Circuit

Basic Low Pass Filter Circuit: The Basic Low Pass Filter Circuit of Fig. 15.7 is commonly used for low pass active filters. The filtering is done by the use of an RC network. The opamp is used as a unity gain amplifier. The resistor RF is equal to R1. (At dc, the capacitive reactance is […]

Active Filters Classification

Active Filters Classification: Active Filters Classification – An electric filter is often a frequency selective circuit that passes a specificed band of frequencies and blocks or attenuates signals of frequencies outside this band. Filters may be classified in a number of ways as follows. Analog or digital filters Passive or active filters Audio (AF) or […]

Types of Filters

Types of Filters: Types of Filters may be of any physical form—electrical, mechanical, pneumatic, hy­draulic, acoustical, etc. The most commonly used filters are of the electrical type. Types of Filters may be classified as follows. Low pass High pass Band pass Band stop All pass Consider a basic configuration of an electrical filter shown in […]

Passive Filters

Passive Filters: Passive filters are mainly networks using inductors, capacitors and resistors. The classical theory employed was based on the image parameter theory which in turn was based on the filter’s characteristics and performance. Its component values were calculated by considering a source having a specified source resistance and feeding it into a constant load […]

Filter Circuit

Filter Circuit: A network designed to attenuate certain frequencies but pass others without attenuation is called a filter. A filter circuit thus possesses at least one pass band, which is a band of frequencies in which the output is approximately equal to the input (attenuation is zero) and an attenuation band in which output is […]