STM32L073VBT6 COST 100mA，Help

[ren yong]

Posted on March 14, 2018 at 08:09

My product with stm32l073vbt6 ran 1 week or longger,the mcu was broken.

All io and peripheral on broken mcu can run as normal,But the power consumption up to 100mA not 100uA!

I have removed all other part but mcu and supply 3.3V my own，the state  not changeï¼�

How can a mcu cost 100mA without any other chip when all function ok？

[Bogdan Golab]

Posted on March 14, 2018 at 08:39

Single board affected? Do you have more boards like this?

Is the MCU hotter now? It's about 0.3W of dissipated power on small...

Are I/O disconnected to prove that the MCU the root cause of the problem?

Can you share the schematic? Just wonder if theoretically this amount of current is possible through I/O

[ren yong]

Posted on March 14, 2018 at 08:52

ALL IO float already，and I had tried connect the reset PIN to GND. It proved that the current cost internal!

[ren yong]

Posted on March 14, 2018 at 08:54

MCU is Hot! And I have two board 100mA and  4 board 4mA!

[ren yong]

Posted on March 14, 2018 at 08:58

[Bogdan Golab]

Posted on March 14, 2018 at 09:01

I would check capacitors. If you assumed that the board broken I would also disconnect xtal.

Divide & Conquer;)

[ren yong]

Posted on March 14, 2018 at 09:08

CAN USB VDD make This

[ren yong]

Posted on March 14, 2018 at 09:14

I  change a new MCU ,the current is ok ,The same board!

[Bogdan Golab]

Posted on March 14, 2018 at 09:15

The idea is to disconnect piece by piece all the external circuitry to prove what is the root cause.

I assumed that you test 'good' and 'bad' board in the same circuimstances and concluded that MCU is broken. Capacitor are likely to fail.

I would disconnect the USB if you suspect it...

[AvaTar]

Posted on March 14, 2018 at 09:25

This suggests the MCU was grilled, probably an EMI issue.

It is almost impossible to reconstruct the cause at this point.

But main suspects are the power supply and IO lines leaving the PCB.