How to power XIAO ESP32S3 from 5V VIN/VBUS with diode?

Hello,

I’m in the process of designing a WLED carrier-board for the XIAO ESP32S3 attached to a 5V/14A power supply.

I’d like to power the XIAO via its 5V VIN/VBUS pin directly from the PSU.
The support page suggests to use any kind of diode when powering this way, probably as to not feed current back to the PSU when USB is attached?

My 2 questions:

  1. What Vf (forward voltage) is acceptable? My understanding is that the voltage-drop across the diode reduces the voltage for the ESP? Is <1V a good starting-point?

  2. What’s the suggested current-rating for the diode? I would’ve gone with a 1A Schottky?

Thank you very much for your help!

Steve

Reference: Getting started guide (underneath 3rd image)

Thank you for that.

I looked at the board’s schematics and the datasheets of the 2 ICs and it appears to me that the module is powered off of 5V directly. No diode used.

Or are you suggesting something else? Would you be so kind to elaborate?
My understanding is that 5V gets fed by the USB connector of the Xiao to the charging IC which charges the BAT and feeds the 3V3 regulator. When the power is sourced from the battery the ETA6003 directs current from the battery to the regulator and into the 3V3 of the Xiao?

But I think my question is answered. Since there is no diode to be found, the Xiao can be powered directly from 5V. Kinda curious as why Seeed does not follow their own suggestions in the Wiki?

somehow it seems to be alot of confusion with regard to powering… as for me i use the expansion boards because i am an experimenter and not a developer the big concern is back feeding power to a computer or sensitive device on the USB

If you’re using the XIAO ESP32S3 for an Ultra Panda 777 project whether it’s a gaming-related task or hardware integration reliable power management is crucial. Ensuring that your XIAO ESP32S3 is correctly powered with protection (using a diode) will help maintain stable operation, preventing disruptions that could affect your Ultra Panda 777 project’s performance.

What is an Ultra Panda 777?

I’ve watched their video on the relay expansion board recently and Seeed Engineers don’t seem to put a diode on the 5V input either.

I’m really curious regarding the voltage drop but as the ESP32 requires 3.3V I guess that the <5V input voltage is going to the on-board regulator so the voltage drop across the diode is not a concern as long as it’s <1,7V.

the diode on the 5v is for reverse protection for the computer or whatever it may be plugged into

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this… it‘s the other way around

Thank you all for clarifying this.

I have added a Schottky diode with 2A of forward-current to the design. That should suffice I guess.

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