http://52midnight.com/tmp/Fig-1.gif

However, I'll need a good output filter, and I'm a novice at such design. What has always puzzled me are the criteria used to establish design parameters. The values of L1 and C1 emerge from the SMPS calculations, but I don't know where to start with L2 and C2.

http://52midnight.com/tmp/Fig-2.gif

As the equivalent circuit of Fig 2 shows, there are effectively two parallel resonant circuits in series. The first one rings at high frequency due to stray capacitance when the switch is off and current drops to zero, and I assume that the second would be sufficiently damped by the resistance of L2 after being "kicked" by the input waveform.

Can anyone suggest an analysis or alternative design approach that would result in optimum values for L2 and C2? Most grateful for any assistance here.

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