In the analog circuit if the power reverse, I should add what protection circuit, what components

Hello Shuai,

There are many different ways to provide reverse voltage protection.  The type of protection and components will depend on the actual circuit you are trying to protect and the actual voltage levels being supplied to it.  Diodes are the simplest form of protection.  However, if you have a 3 volt supply and the voltage drop on the diode is 0.7 volts, then you circuit may not work properly.

Perhaps you can describe your circuit in a little more detail so that more people can provide you with a possible solution.

Thanks,

Hi Shuai,

Like greenja said above it's depend on the circuit, I assume You use op amp with +/-12V or +/-15V then I usually use a flameproof or fusible resistor with diode like in the attachment, but I'm not an expert