STM32L4R5ZIT6P ESD Damage

[ym21]

Hello, 

I may have accidently either shorted or applied voltage to my UART TX and RX pins on my MCU which is on a custom PCB and now my PCB is pulling +60 mA of current under load. I am now experiencing difficulty programming the chip and I am getting errors such as "unable to recognize device" and "check power and cable". I wonder if exposing my UART pins to ground or power caused some sort of ESD or electrical damage inside the MCU and that combined with a longer power supply cable is causing a jump in current that makes it difficult to flash now?

Thank you.

[TDK]

Shorting GPIO pins to GND or VDD is not ESD damage and generally will not damage the chip.

> PCB is pulling +60 mA of current under load

So there likely is hardware damage. Could be that there are hardware issues that have caused damage cumulatively. Could be pins seeing overvoltage.

[STOne-32]

Dear @ym21 ,

Indeed it seems more like an EOS - Electrical Over Stress beyond the pins and product AMR - Absolute Maximum Rating . Can you keep your Reset/pin low and measure the current under reset and let us know ? If the current is excessive not few mA , the Device is damaged for sure .

Hope it helps you ,

STOne-32

[ym21]

When I pull NRST down to ground, the PCB is pulling elevated levels of current.