Board description
AN2451
24/55
Doc ID 12791 Rev 3
Figure 15.
Simulated frequency response of the Rx passive filter with components
tolerance effect
5.1.4 Input
impedance
The input impedance of a powerline communication node is another critical point.
and
show the input impedance magnitude vs. frequency curves in both Tx and Rx
mode. In both figures channel impedance point and the minimum impedance point are
indicated.
The impedance magnitude values prove that the ST7540 reference design board is
compliant with the EN50065-7 document, which sets the following minimum impedance
constraints for this kind of equipment:
●
Tx mode:
–
free in the range 3 to 95 kHz
–
3
Ω
from 95 to 148.5 kHz
●
Rx mode:
–
10
Ω
from 3 to 9 kHz
–
50
Ω
between 9 and 95 kHz only inside signal bandwidth (free for frequencies
outside signal bandwidth)
–
5
Ω
from 95 to 148.5 kHz
‐
1.5 dB
