Rock Pi 4C+ and NVMe - 5V 5A USB-C non-PD power supply?

#1

The docs say [1] that the Rock Pi 4C+ USB-C power input is non-PD, but also say for NVMe usage a 5V 5A (25W) power supply is needed.

Does anyone know of a US mains AC 110V/120V USB-C power supply meeting that definition? And/or a 12V DC input power supply meeting that definition (for use in an RV)?

Thanks!

[1] https://dl.radxa.com/rockpi4/docs/hw/rockpi4/rockpi4c_plus_product_brief.pdf

"4.1 Power Requirements

The ROCK Pi 4C Plus can only be powered by +5V.

• USB C 5V
• 5V Power from the GPIO PIN 2 & 4

The recommended power source capacity is at least 5V/3A without M.2 SSD or 5V/5A using with M.2 SSD."

#2

There’s a reason every powering spec stops at 3A with 5V (and defines higher power modes with higher voltages): Ohm’s law.

At 5V it looks like this:

To compensate for the voltage drop at 5V/3A already very thick and ultra short cables are necessary so simply forget about anything above. Asking for 5V/5A is insane. At the board you get either 5V or 5A but never both at the same time.

IMO the RPi 15W USB-C power brick is the best piece of hardware RPi Trading Ltd. ever manufactured since able to provide rather stable 5V up to 2.5A. Most probably your best choice asides an SSD known for low peak power consumption to avoid voltage drops when the SSD starts or wakes up from sleep states.

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#3

I really wish we didn’t use PD power and standardised on 12v as 12v rail is also pretty handy but 5v is just a step down reg on the input.
There is a huge array of relatively low cost barrel type often called ‘cctv’ psu but guess where things are progressing 12v will also hit limits at some point.
I guess you can use PD with one of those fixed neg devices and negotiate 12v but prob just cheaper to standardise on a single SBC voltage, but there are components that require 12v.

Those RPi 15W USB-C power bricks are a really great price as tried before to source elsewhere and found not really at that price.