MSP430F5419A: MCU resetting during switching

Furkan Fehmi Sefiloglu

Hi Team,

Can you please check and advise following request?

We are experiencing problems with our devices, especially during contactor switching with relays.
It is seen that the cause of this problem occurs as a result of being affected by the EMIs that occur at the time of contactor switching and reflecting on the GND.
The problem of resetting is that the MCU has low immunity against such interference and our PCBs are not prepared in accordance with EMC rules.

Thanks in advance

Best Regards

Furkan Sefiloglu

over 5 years ago

0 Eddie LaCost over 5 years ago

TI__Mastermind 47645 points

Hello Furkan,

The first thing to check are the resistor and capacitor on the reset pin. See table 1-3 in the users guide. If they do not have an external 47k pull up, they can enable the internal pull up resistor.

https://www.ti.com/lit/ug/slau208q/slau208q.pdf

0 Hakan CAM over 5 years ago in reply to Eddie LaCost

Prodigy 10 points

Hello,

We have 10K pull-up resistor and added 1.5nF ceramic capacitor to the reset pin pulled down to gnd.

We still have the same problem. This capacitor did not solve the problem. fyi.

Best regards

Hakan Çam

0 Eddie LaCost over 5 years ago in reply to Hakan CAM

TI__Mastermind 47645 points

Hello Hakan,

Are you able to observe the RST line toggling during an EMI event? It would be good to check VCC and the TEST pin. If there is excessive noise, the TEST pin can also cause issues. You could also try adding a 1k pull down resistor on the TEST pin.

Also, see table 1-26 of the users guide. You can check SYSRSTIV to identify the cause of the last reset.

https://www.ti.com/lit/ug/slau208q/slau208q.pdf

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MSP430F5419A: MCU resetting during switching