I have been asked to create a dimming system (Along with other features) that interfaces to the cheap LED strip lights. A lot of people seem to use standard N-FETs with PWM on the low side. My concern is with a long strip (3M) wouldn't this produce a large amount of EMC/EMI due to a hard edged voltage and current wave?
Should the design instead incorporate more of a buck style control with an LC filter to smooth the output waveform? And effectively make it analog dimming if EMC/EMI or radiated emissions is of concern to for instance pass FCC or CE tester? Note values in schematic are for reference only, not calculated.
If so, is there an easy way to do it without a high side switch, or an easy way to efficiently drive it from 0 to 100% PWM?