Does anybody know the max current rating of the 3.3v and 5 v rail of the new raspberry pi 4? i could not seem to find anybody benchmark this, i have read from someone that the new RPI 4 has a new switching voltage regulator and was wondering is current rating.
If the power source matters i am interested in the normal USB-c port and the POE pins ( Direct to 5v rail)
You will not find a specification, because there isn't one.
The Pi4 has the same power manager as the Pi3B+ and Pi3A+ so the current limitation would be the same (the PMIC is rated at 1.5A). The Pi3 regulator is rated at 1A and has been tested at 800mA (on 3.3V).
There is no polyfuse or limitation on 5V, so you could in principle draw up to the limit of the power supply, but this would be limited by the copper board traces.
30mA for 3.3V (GPIO pins) For 5V there is no actual limit because that is directly attached with the power chip. Using 5 V rail is dangerous than using a USB type-C.
