D15V35F5S3: Isolate the 5V out from separate 5V source?

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1

Hi, I’m planning to power an LED strip using the 5V, 9A voltage regulator D15V35F5S3 to step down battery voltage, with an additional power jack to connect a 5V regulated wall power supply.

Only one will be connected at a time, so either the battery will be providing 5V to the circuit via the regulator, or else 5V will be coming in from an external source.

The question is: should I isolate the VOUT on the regulator when 5V is coming in from another source and VIN on the regulator is disconnected? Is there any risk of the module being damaged in that case?

Isolation could be as simple as a mechanical SPDT switch to selectively connect either the regulator or wall source to the rest of the circuit.

Thanks!

2

Hello.

I do not think that applying 5V to the output of that regulator while it is not powered would probably damage it, but in general, it is not good practice. Your plan of adding a switch to prevent power from flowing back into the output of the regulator sounds like a good idea.

- Grant

3

Thanks very much for the answer. I’ll do that!