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TPS61222: Automatic power source selector for an output with TPS61222 (5V fixed) and an external source of 5V

Part Number: TPS61222


I'm developing a project where the main input source is a 3V Lithium coin battery like this:

So I used a TPS61222 because I need a fixed 5V output to power a circuit with ATmega328/Arduino.
However, the design will also support an external 5V voltage source. For this, I thought of using a schottky diode, from the external 5V to the internal 5V generated by the TPS61222, as shown in the figure below:

I did this to ensure that the internal 5v source does not conduct current to the external 5V source.

By observing the functional block diagram of the datasheet of the TPS6122x, I see that the MOSFET at the VOUT output has a diode that protects against current in the opposite direction. In this way, I decided not to put a schottky diode, from the internal 5V source to the external 5V source. Because I also do not want a voltage drop at the internal 5V source output.

My project has to be low cost, so I did not choose to use automatic selection circuit like those of the Arduino Uno board, nor have I own ICs for automatic selection of sources like some LTCs that I've been researching.

My question is: how am I implementing the circuit, do I have any risk of damaging the TPS61222 when the two power supplies are turned on simultaneously?

PS.: English by google translator!