For specific filtering requirements in a given application, you may find multiple design options. Ferrite beads are commonly used along with capacitors to suppress the noises generated from switching power supplies. So i am hoping maybe you guys can suggest an Input EMI filter than has physically smaller magnetics and capacitances, to just meet the CE Conducted emissions limits and yet meet our size constraints. In EMI filter design, the core of materials used in the inductor design matters. So, for my current design, it suggests 6mH and the part number it gives, i checked it, its too huge to fit our PCB as well as confined space. Now i am not saying there is an error in the PI Expert suggestions, i do understand there can be more than one way to get it right. This made the conducted emissions within the limits and we passed the tests. This was also designed in PI Expert initially, PI Expert gave us a Single-ended Inductor (1mH) with associated componentry as the Input EMI filter, but then, after it failed CE, we were suggested to use the Common-Mode choke (15uH) with the caps (6.8uF -AND- 10uF) to correct for it. The tool is developed using MATLAB and also has a GUI. The layout, well, that is very tight and we do ensure to make the loop areas very small with a little more than ample trace widths, to ensure very low resistance current paths.Īs a reference, i am attaching the other PSU schematic i mentioned in my post, for one of our other products. a tool which can aid a designer to get an idea of the volume of an EMI filter. So i am confident the transformer is not much of a problem here, maybe a little bit but not too much to worry. Though i have not cut through the transformer physically to check if it is made exactly as per the details, however, it did not give us any problems so far in our previous design.
The Transformer we get from a listed vendor of ours (a Transformer factory in China), based on the Transformer specs as provided by PI Expert software. I understand that PI Expert gave me a suggested value for the Input EMI circuitry.
#Emi Filter Design Software pdf#
I am attaching my Circuit as made in PI Expert here (both, UDS file as well as a PDF file), for reference. Can you please have a look and suggest a choke that is in the uH range (thus smaller size) AND associated components for EMI filtering ? This leads me to think that there can be other possibilities apart from the 6mH CM-Choke suggested by the PI Expert. And yet it failed CE conducted emissions testing, then we later used a 15uH (micro-Henry) CM-Choke with appropriate caps to just meet the CE requirements. I have done another design previously with a TNY284 chip, and a similar high-value Inductor was suggested (PI Filter) - i think it was a 1mH one. The CM-Choke alone increases the height / width by a magnitude.
My design is supposed to be a very compact PSU, almost like a module, to be used in a custom consumer electronics device.
#Emi Filter Design Software software#
I selected a Common-mode EMI filter, and the PI Expert software suggests a 6 milli-Henry CM Choke. Isolated, with TL431 and Opto-coupler feedback. I designed a circuit in PI Expert with following specs : Emi Filter Design Software Rating: 3,9/5 2869reviews Martin Testing EMIEMC, Capabilities and Facilities Covering.
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