lpc5460x cannot work after power up

[yanqinghe]

Dear NXP:

     My chip is lpc54608s512 ,  it's a strange phenomenon ; The MCU works normal for a lot of days, but one day, it can't works after power up , and need power up twice then it works well too;  If the two power up interval too long ,it's can't  works too;

      Do you know what's the matter with the MCU?

[jw145]

We have a similar issue as well, very confused why it is happening. Happens the same on 3/3 custom PCBs but not every time we power them on. 

[Carlos_Mendoza]

Hi yanqinghe,

Are you using an evaluation board? Does the same happen if you are running a simple demo program?

You mention that if the interval between the two resets is long then it can work, right? This sounds like a capacitor in your board is still charged and the remaining voltage is preventing the MCU from powering up correctly.

Best Regards,
Carlos Mendoza
Technical Support Engineer

[yanqinghe]

Dear Carlos Mendoza:

        I'm not using an evaluation board, we designed the board refer to the evaluation board.

I means if the interval between the two resets is long then it can't work; It looks like a capacitor must charge and then the MCU can power up ;  Another phenomenon is when the MCU can't power up , the system 3.3V was pull down to 1.6V, the MCU temperature is a little high. After power off and power up the board at once, the board works normal, the software running well too ; when the MCU is running  it looks well and the temperature is right too;

Best Regards

  Yan

[nikolastojkov]

Dear Yan,

We are experiencing the same issue on our boards. Did you fiund out the root cause of the issue ?

BR

Nikola