Take a look at what type of bead they use in your PC's power supply. Another good source is the old CRT monitors, they usually had a fairly large bead to keep the HF from getting back to the power supply.
I am not an expert on the beads, but I have been involved in projects where we needed to cut down on the inrush currents and the engineers I worked with used the beads effectively.
If the inrush if from large capacistors in the circut, ferrit beeds does not help you - you will need a larger inductor to do the jobb then, but it is better done with a mosfet as a current limiter.
Or just seash for "an1542" it is a more or less standard AN to read.
I have used inductiv, fixed value resistors, NTC and active MOSFET controll i designs in order to keep the inrush under controll - With EUP and for mbattery powered equipment it is not an option to use the NTC because it lowers the system over all effinency. One other option that is usefull in some situations is the PROFET from INFINEON - you have to check there datasheet - they have serveral different for different applications.
I have used some hot-swap control methods in my designs which does similiar functions like inrush/over current limiting....... which is same as mentioned in the article like soft turn on of a MOSFET.....
The inrush current is largely depends on the value of the bulk capacitor on the supply input(like dc-dc converter input cap) which are used as a temporary storage and it's value largely varies with the input voltage range.....
its always better to use the active control method such as turning on a MOSFET slowly initially to avoid the initial inrush.......but in this case, considering such solutions costly i would suggest to add an inductor in series with the input capacitor.......
NTC is also a good option since its available even in 20mohms at max current now but it can be a little bulky.......selection largely depends on what resistance value is required during the turn-on time(or what current to be limited).....
Hi, check out the FPF2123FPF2123 from Fairchild Semiconductor, its a load switch with programmable overcurrent limit, it will operate at constant current when the (programmable) limit is reached, otherwise it will just turn fully on. should solve your problem!
