Question
STM32L071 MCU Bootup fails
Hi ST team,
We are using STM32L071 for the system bootup application. We are observing that for few of the boards - NRST was asserting due to which ST MCU fails to boot. Our initial suspect was on 3.3V Power rail. We did an experiment as below:
- When the injected residual voltage reaches approximately 0.25V on the 3.3V rail, the U1501 fails to start up.
- When the residual voltage is below 0.20V or above 0.30V, the U1501 starts up normally.
What might be the possible reason for NRST pin getting low? Please find the schematics and probed NRST pin.
