STM32H745 SMPS Wiring

[armandoedesigns]

Hi,

I'm working on the wiring of the STM32H745, but I'm a bit confused about the wiring to enable the SMPS.

If you look at the Figure 13. Power supply scheme, there isn't any inductor or cap in the SMPS pins. (I presume they are connected to VDD?)

If you refer to the Figure 16. External components for SMPS step-down converter there are two different diagrams. "Direct SMPS supply" and "External SMPS supply, LDO supplied by SMPS" What are the difference between them? 

[FBL]

Hello @armandoedesigns,

If you look at the Figure 13. Power supply scheme, there isn't any inductor or cap in the SMPS pins. (I presume they are connected to VDD?)

> You can the suitable configuration as referenced in RM0433 Figure 22. System supply configurations

In the "External SMPS supply, LDO supplied by SMPS" diagram, an external LDO regulator is used to regulate the voltage from the SMPS before it is supplied to the VDD pin of the MCU. This is done to provide a more stable and regulated voltage to the MCU. 

I hope this helps!

[armandoedesigns]

Hi,

This is the configuration I'm using to enable the SMPS, not sure if its correct following the data sheet? It is not very clear.