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I'm going to use board mount power supply (IRM-30-12) for first time. It has class 2 protections as per datasheet. Does it really protect my digital circuit in case of Hazardous situations like lightening and others?

Should I place any switching regulator/ battery charging components on its either side of PCB?

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Does it really protect my digital circuit in case of Hazardous situations like lightening and others?

The data sheet says this about surges: -

EN55024, heavy industry level (surge L-N : 1KV), criteria A

And all that means is that the unit will survive a 1 kV surge when applied to the AC lines. It doesn't mean that a surge will not produce a knock-on transient of some form on the DC output so you need to take care of down-stream effects yourself. These days, surviving a 1 kV surge is old-hat and rather feeble so, you have to put things into context. If you can, try and find a device with better survival qualities - for instance, ethernet devices tend to be able to survive 6 kV.

However, the data sheet also says this: -

Protection type : Shut off o/p voltage, clamping by zener diode

And that likely means that the output DC voltage is fairly hard-limited to some upper value but there's no guarantee that your electronics can survive that upper value. For a 5 volt output power supply, the upper value is stated as being 6.75 volts - so, is your electronics capable of surviving that extreme?

You also need to consider that surges can produce a common-mode transient on the DC output and this may also cause your load a problem especially if your load is not galvanically isolated from earth.

Summary: It depends on your circuit!

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  • \$\begingroup\$ As I use 12v out the upper value is stated 16.2v in the datasheet. I have limited the voltage using overvoltage protector TISP4015L1BJR-S and SMBJ15A(TVS) in the DC input line, however the maximum input my regulator can accept is up to 40v(LM2596s). Will it get the transient issue to my load ? @Andy aka \$\endgroup\$ – PCBLearner182 Jun 25 at 6:37
  • \$\begingroup\$ @PCBLearner182 there are some questions that cannot be 100% answered but, if your regulator is good for 40 volts then you should have confidence in surviving non-common-mode transients from the device. Common-mode is difficult to judge because there are so many factors to consider and it's probably wise to do a test. \$\endgroup\$ – Andy aka Jun 25 at 7:42
  • \$\begingroup\$ Thank you. I'll do it. There is one more doubt I have regarding pcb design. Should I pour or remove copper on both top and bottom part where I placed the mounted converter (IRM-30-12). Should I place battery charging components on either layer of the converter? @Andy aka \$\endgroup\$ – PCBLearner182 Jun 25 at 7:51
  • \$\begingroup\$ What does the data sheet tell you and also remember that you need clearance between live AC inputs and DC outputs for safety reasons. Never skimp on this requirement. I can't answer for you battery charging components because there are no generalizations I could make. The devil is always in the detail. \$\endgroup\$ – Andy aka Jun 25 at 7:55

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