Copper telephone wires were originally designed to carry “commercial speech” using a band of frequencies from 300 Hz to 3400 Hz through a system called the PSTN (Public Switched Telephone Network). The ADSL (Asymmetric Digital Subscriber Line) uses frequencies very much higher than this speech band to carry fast data traffic using frequencies between 25 kHz and 1.1 MHz. To ensure that the higher- frequency transmissions do not interfere with normal phone electronics, fi lters like that shown in Figure P22.86 must be installed on all phone lines.
(a) Calculate the frequencies that would be filtered out with the circuit configuration in the figure. Do they fall in the ADSL transmission range?
(b) If the three inductors in series on each line were instead replaced by one equivalent inductor, would it alter the effectiveness of the filter? Why or why not? 

Transcribed Image Text:

220 μΗ 10 μΗ 22 Ω 40 μΗ ο0 Input 22 nF 22 Ω Output 40 μΗ 220 μΗ 10 μΗ ll οο Figure P22.86