For a Powerline Communication device that uses the frequency band 42 to 89 kHz. I need to choose a power supply that will not add noise in the powerline and kill my communication band. There are two devices with certain current requirements; the first needs 1 A and the second needs 4 A.
I have looked at the available power supplies and tried adding a mains filter to suppress the EMC noise out of it (see figure below).
This will attenuate the communication signal as well, due to the Cx cap on the line (see figure below). So my best option at this point is to choose a better PSU to solve the problem.
I am looking for two designs or models of a switching mode power supply that will output 1 A or 3 A that has a high enough frequency that it harmonics will not interfere with the communication band between 42 to 89 kHz.
Best Answer
If you are using a SOC PLC device from STM you could maybe have a look at the ALTAIR04- 900 device as it was a recommended power supply in a datasheet for one of their devices. Page 56 of this document. They also have an example of the power supply input EMI filter- designed for the CENELEC A Band which is the frequency band your are interested in (page 57).