I want my st25dv64k to communicate with stm32 mcu using i2c. Is it necessary to power st25dv64k with 3.3v or will Energy Harvesting able to power i2c communication in presence of a NFC Mobile.

[RGeorge]

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[S.Ma]

Can't answer generic question. Power consumption of STM32H7 is a bit different than STM32L0

If it is a must, you need to do a power budget homework and also prepare the MCU S/W for all the low power modes and also the detection of a failing power supply, size properly the decoupling caps etc...