A TI paper said that one way to address this issue would be to slow down the charge of the capacitors... which got me thinking...
Inrush current into the power supply caps is what the supply can deliver.Could be a lot more than 2Amp. You can only measure that with a scope, not with a slow DMM.Current draw of a class-D amplifier depends on supply voltage and speaker impedance.With 8-ohm satellite speakers (not including woofer), and a 24volt supply, that could already be ~4Amp full blast.I expect you need a 24volt/10A supply for that board.How are the RPI/Nano powered.Should be a separate supply, or that buck supply should be buffered with a cap and diode between the two supplies.Leo..
If a MOSFET is used for the switching maybe slowing down the turn on by a large Gate resistor and possibly a capacitor could solve this. But of course the transistor will dissipate a lot of power during turn on/off. It can easily die if it is too small. (I have no idea how large transistor you need for this - using two transistors is probably better.)
[...] The solution was to just have the smaller supply charge a 1 Farad capacitor with a 2.5A polyswitch connected in series. That was more than 10 years ago, and I think its still in service.Anyways, I would think that perhaps a suitable polyswitch directly charging a capacitor could solve the problem. There are many types and sizes to choose from, some have a faster trip time than others. If your amplifier is oversized, and your continuous current draw is under 0.5 amp, then a 500mA polyswitch limiting the max current to 1 amp just might work.
From datasheets I got impression that common PTC "fuses" take looong time to fire - tens or hundreds of ms even with considerable overcurrent. Is it a good device to prevent brownout?
PTC Example 10ms trip, 0.35A hold