STM32H7 series questions ( LQFP)

[D Zero]

Posted on November 04, 2017 at 16:24

Dear *,

I have some questions about the STM32H7 series:

1) As i see the MCU can work from 1.6V to 3.5V power supply. 

a) if i set the VDD to 1.8V than all the I/O and interface pins are 1.8V logic ? 

b) is it possible to use other supply for some group of pins ?  eg. PA pins are using 3.3V logic and PF pins are using 1.8V logic ?

2) About the DRAM Memory controller. It is specified that it can use  SDRAM/LPSDR SDRAM

a) the SDRAM is 3.3V(most that are still active)  -> i have to use 3.3V VDD and all interfaces are 3.3V ?

b) the LPSDR SDRAM is 1.8V -> i have to use 1.8V VDD and all interfaces are 1.8V?

c) both SDRAM and LPSDR SDRAM are not double data rate ,is this correct?

d) can we also use SDRAM mobile like this one IS42VM16160K-75BLI with the MCU 

Best Regards.

[Szymon PANECKI]

Posted on November 05, 2017 at 16:32

Hello David,

Thank you for your interest in STM32H7 MCUs. Let me provide you a feedback regarding your question number 1.

1a)

I confirm your assumption. When VDD is equal to 1.8V, then all I/O pins will use 1.8V logic (high logical state will have value 1.8V).

1b)

No, it is not possible to supply some of I/O pins with other voltage than VDD in STM32H7 family. Such solution is available for example in STM32L4 family, where some of packages (those with high number of pins) are equipped with VDDIO2 pin, which exclusively supplies dedicated I/O pins. In such case it is possible for some pins to use 3.3V logic and other pins can use 1.8V logic. But this is not possible for H7 family.

Best regards

Szymon