STM32N657L0H3Q power architecture

[foc]

Hello ST team,
I am designing a circuit using the STM32N657 and want to minimise the total power consumption in this application. therefore, I am considering using the ultra-low-power U031 MCU to switch the STM32N6 on and off via this MCU. My question is: can I use a power switch instead of an LDO?
I have attached my power tree I’d appreciate it if you could have a look.

Regards
 

 

[KDJEM.1]

Hello ​@foc ;

 

Do you mean that it's possible to use a switching power supply? 

If yes, I recommend you to look at the External SMPS supply (Bypass) mode which is on DS14791 on the right in Figure 2. This power supply can be produced by externa DC-DC converter or LDO. This is the configuration of our STM32N6570-DK and NUCLEON657X0-Q boards. 

 

Thank you.

Kaouthar

[foc]

Hello Kaouthar,
Thank you for your reply. My question concerns generating 1.8 V from a single SMPS and using power switches (rather than LDOs or SMPS units) to implement the power-up sequence. Is this a suitable method for doing this? Or should I use separate LDOs or power supplies for each VDD line?
 

Regards