Kathy Obarowski

Power Supply Filtering

Discussion created by Kathy Obarowski on Nov 1, 2011
Latest reply on Nov 3, 2011 by bigmac


We have a new design engineer who is complaining about our old designs - specifically power filtering.  We now have the 5V power going to a 10uh inductor followed by a 10uF, 0.1uf and 0.01uf cap.  He is concerned that there will be a surge of current from the microprocessor causing ringing and wants to add a 1 ohm resistor in series with a 39uF cap across the 5 volts after the inductor.  This  would be repeated for all three voltages - VDDX, VDDR, and VDDA.  Is this necessary?  Thanks