ku637
Advanced Member level 4
Hi,
Im working on an AC/DC converter (15W output) Input 85-265VAC.
This has a particular requirement of having a very low conducted emission of 1dBuV in the band 2-30MHz
i need to provide around 60dB attenutation for Common Mode (CM)& Differential mode (DM) noise based on a reference design EMI test results..
What i know about EMI filter design is like the passive stage with common mode choke with X & Y capacitors..
I dont really know how to select appropriate components in the design...
Im having some basic doubts ..like
1)is this 60dB attainable using passive filters.. may be atleast by two stages??
2) what are the parameters need to be considered while selecting the filter components like CM choke, X capacitors , Y capacitors..etc
will looking the parameters like SRF,I saturation,Impedace at operational frequency will suffice??
5) How to arrive at a suitable component values ..by simulation..
while thinking about simulation .. im confused about the source & load impedances ( may be i should use 50Ohms impedance)
The actual models to be used etc..Im familiar with ADS,LTspice etc...
Thanks for any help,
Im working on an AC/DC converter (15W output) Input 85-265VAC.
This has a particular requirement of having a very low conducted emission of 1dBuV in the band 2-30MHz
i need to provide around 60dB attenutation for Common Mode (CM)& Differential mode (DM) noise based on a reference design EMI test results..
What i know about EMI filter design is like the passive stage with common mode choke with X & Y capacitors..
I dont really know how to select appropriate components in the design...
Im having some basic doubts ..like
1)is this 60dB attainable using passive filters.. may be atleast by two stages??
2) what are the parameters need to be considered while selecting the filter components like CM choke, X capacitors , Y capacitors..etc
will looking the parameters like SRF,I saturation,Impedace at operational frequency will suffice??
5) How to arrive at a suitable component values ..by simulation..
while thinking about simulation .. im confused about the source & load impedances ( may be i should use 50Ohms impedance)
The actual models to be used etc..Im familiar with ADS,LTspice etc...
Thanks for any help,