i am designing our stm32l476 board and want to make sure beforehand that i can use Vref refference voltage in the AD conversion or not. i think internal ADC use is available while vbuf+ is conbined with vdda in 64pin package. am i right?

[raptorhal2]

Yes. See 18.4.1 in the reference manual.

Higher pin packages provide for a reference voltage different from the Vdda ADC supply voltage.