if the VDD is powered,can spi communicate?

[jingfang]

if the VDD is powered,can spi communicate?

I use MCSSFS4503's buck3 to MCU'S VDD and LDO2 to MCU's VDDA.

LDO2 requires SPI communication before output.

And if VDD and VDDA have voltage difference whether the following rules are violated?

[PetrS · Accepted solution]

Hi,

you should not use such kind of design. VDD and VDDA must be shorted to a common source on PCB, so you violate the rules given MCU's DS.

BR, Petr