Multiple Power Source Entry Points

[lixnig]

Hello, Everyone.

I am building a system in which I have a single 9V power source being converted into a myriad of other voltage levels. Several of these conversions are done using MCP1802 regulators. I am considering bringing out the converted voltage supply nets (Vout of the regulators) to a couple of headers on the PCB for both voltage verification purposes and also in case it becomes necessary to directly supply any of these using a benchtop PSU.

My question is if I decide to apply an external voltage to the Vout side of a regulator, should I include diodes on the Vout pins of the regulators? If so, does anyone have a recommendation for an SMD diode family?

 

[shatruddha]

well yes, you should be applying diodes to prevent your circuitry. To provide you with a solution of diodes, first we need to know maximum reverse voltage on the diodes in case of an external supply.