STM32H723 .. 735 at 1.8V (because of HyperRam)

[LCE]

Heyho,

just when we got the quote from our PCB assembly company for a prototype of a big board with the STM32H733, I find that basically all HyperRam ICs with 3.3V are EOL. 

There’s no alternative to 8-pin HyperRam due to IOs, routing, and board space, so the best would be to switch the complete system from 3.3 V to 1.8 V.
BTW, I find that the HyperRams are working great with the H7, 11 IOs, only, fast, relatively low power, no problems at all so far.

It’s 2026, darn… I started working as an EE at around 2000, and then the 5V → 3.3V transition was mostly done. Now it’s time for 1.8 V.

Anyway, I checked the H73x datasheets, and looks like these are fully operable at 1.8V without any problems (only exception: the internal OPAMP needs >= 2.0V, but we don’t use that), at full clock and IO speed.

So my questions to the H723..H735 users:

• Anything I did oversee or forgot ?
• What’s your experience running the H7 at 1.8 V ?

Changing the rest of the components is another … PITA, but first I need to know if the H7 as the “heart and brains” of the system is fully capable at 1.8 V.

Please share your thoughts!

Thanks in advance!

[STOne-32]

Dear ​@LCE ,

 

1.8V is already de facto the standard for all STM32 consumers applications since the STM32F2 and STM32F4 series  and before H7 series and running at full speed and full potential such as I/O are boosted with HSLV mode to keep the same performance as it was with 3.3V and keeping the same robustness versus EMC stress , so matching the Robust Industrial Markets. further more  now , we introduced 1.2Volts I/O but with reduced performance.

The only care is for all analog / dynamic range such as ADC, DAC , OPAMP, and USB PHY , for that operations we have dedicated power supply pins at 3.3V and you can keep both rails on same PCB : all digital powers at 1.8V and specific Analog ( if required at application level ) with 3.3V.

Hope it helps ,

STOne-32