FS5613 DEBUG mode low VCCA voltage

[mrajzr]

Hello!

After entering DEBUG mode we can observe VPRE, VCORE, VAUX (5V) being of correct value, however VCCA which should be 5V is instead 3V. After programming the microcontroller and running the code on it, the voltage reaches expected 5V. Select resistor is 12k. VCCA is used to power on uC pins, and VAUX is used to power ADC. What could be the reason behind that?

[ErikaC]

Hello,

Just to confirm, are you using FS56 or FS65?

[mrajzr]

Hello, yes I meant FS65.

[ErikaC · Accepted solution]

Hello,

It is high possibility due to overcurrent after VCCA. Vcca 5V should be stable no matter device powerup or normal running.

[mrajzr]

Hi ErikaC, thank you for the hint, it was in fact debugger drawing too much current through one of its pins