Is this decoupling configuration for the STM32F407ZET6 correct

[Noah_Stoessel]

Hello im creating one of my first stm32 boards and need some help ive watched many tutorials about decoupling capacitors and have referenced what i could from the datasheet could anyone confirm if this decoupling setup would work or if modifications are needed:grinning_face:. I am using a usb-c connector for programming and power with an ams1117 3.3 volt regulator with the appropriate solid tantalum capacitors. For a little more info these are all smd 0603 capacitors and the component marked fb1 is a ferrite bead with a resitance of 120ohms at 100mhz.

[Noah_Stoessel]

All taken care of now any recommendations for a good switching regulator?:grinning_face:

[LCE]

> All taken care of now any recommendations for a good switching regulator?

Haha, good one... too many out there.

Besides the technical specs (Vin, Vout, Iout, fsw, efficiency, size) look for availability, cost, and pin compatibility - if that matters to you.

If you can spare the money, chose an LT/ADI switcher. Costly, but mostly simple, and very reliable (never let me down in the last 25 years).

When doing the PCB layout, read the datasheet, understand where big (switching) currents are flowing and keep these paths short.

[RhSilicon]

It might be interesting to know this:

Transmission Lines - Signal Transmission and Reflection

https://www.youtube.com/watch?v=ozeYaikI11g

Why is reflected power bad?

The reflected power from a bad load will put additional stresses on the transmission lines. As an example, if the normal transmitter power is 10,000 watts and the load has a VSWR of 1.05:1, the maximum RMS voltage in a 50-ohm transmission line will be 725 volts with a peak voltage of 1,025 volts.

https://www.radioworld.com/news-and-business/the-abcs-of-swr-vswr-reflected-power-and-return-loss

[LCE]

@RhSilicon WTF? 10kW? What do you want to tell us? That's mostly irrelevant for this topic, ignore above post @Noah_Stoessel 

[RhSilicon]

Keep ignoring it's better.

[LCE]

It's some interesting information, but rather off topic concerning a low power MCU power supply.

Or I don't get it, so please explain @RhSilicon 

Or isn't that about high power radio frequency transmission, and not about DC power supply?

[RhSilicon]

There's a video link in the ignored answer that maybe could help someone interested understand the subject a little better, but it's better to ignore it, it's more of an engineering subject.

[LCE]

Okay, now I get it... you refer to my switching regulator layout hints.
But still, it is a little too far-fetched IMO concerning the layout of a switching regulator.

That's why I tried to sum things up with:

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When doing the PCB layout, read the datasheet, understand where big (switching) currents are flowing and keep these paths short.

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