Powering Nextion with LDO

#1

Hi, i’ve made a system that use a LDO to power up the nextion Screen, an MIC29300-5.0WT 3A@5V

But after some seconds, the screen power loop, the LDO became very hot and are noisy. It made frie an Bluetooth module on an other LDO (same power supply, same GND but not same 5V output) and other components crash. I’ve tryed just the LDO and the screen but no effect, still power loop.

When i test on the usb phone charger, it work without trouble… WTF…

I’ve found this topic Nextion and audio - some PSU tips, can it solve my prob ?

#2

The problem is that the Nextion draws a lot more than the nominal current on startup, not continuously, but for one or more short inrush current peaks. This is mostly due to the boost converter for the backlight.
If your voltage regulator is designed to slowly rise its output voltage until it reaches nominal voltage, the Nextion will try to start at an arbitrary point of the power rise curve which leads to stability problems.
This can be solved in two ways: First, use a power supply and a regulator with quick rise time, or second (better) a power supply/voltage regulator with a separate so-called “power good” signal pin which will then activate a power MOSFET switch for the Nextion.

#3

It start correctly the first time , it’s some seconds after maybe 30/40sec, it start to loop. The current drawn at this time is only 470mA… it’s not a problem with the peak current i think