I am working with STM32 L452 microcontroller. I'm trying to program this using SWD interface on ST link debugger of the Nucleo board. I am powering the L452 MCU via two different methods :
1) Using the 3.3V supply from the nucleo board
2) Using my custom power supply ( 30V---[buck conversion]---> 5V ---[LDO]----> 3.3V )
What is causing the problem here ?
PS : I'm using the following three pins from the SWD interface :