Hello, I'm trying to decide how to design the power scheme that will supply the various voltages within my project. The two big requirements are that there is a single main supply, regulated 5V @ 1A (typ. load .5A), and extremely low noise regulated 12V @ 1A (typ. load .4A). The low noise 12V is for an RFID reader that reads 134.2kHz transponders. Below are the two designs that I'm contemplating. Design 1: Main supply is regulated 15V linear supply;5V switching regulator (260kHz switching freq.) with ferrite beads on both input and output to reduce conducted noise;12V low noise linear regulator (LT1763) with filtering added. Design 2: Main supply is regulated 12V linear supply;5V switching regulator (260kHz switching freq.) with ferrite beads on both input and output to reduce conducted noise;filter 12V main supply to provide extremely low noise 12V Design 2 is the least complex but the second linear regulator in design 1 should help to further clean up the 15V main supply and attenuate any noise caused by the 5V switching regulator. Please offer your thoughts on these two designs and which one you might choose. Any and all thoughts/recommendations are appreciated. Thanks.