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MSP430F5310: MCU hangs-up at start-up

Vincenzo Pizzolante
Mastermind 25676 points
Part Number: MSP430F5310


hi,

Out product is connected to a 12V main supply, which is stepped down with a linear regulator (TLV70133).

The connection to the main supply is made through a connector. We had reports that the product is failing at power up and sometimes even after main power up.

In order to reproduce the behavior we tried in lab some test.  We made several imperfect connection of the main connector (removed and trembled insert), and at some point the device did not power up although the connector was fully inserted.

After voltage analysis we could see that the device did not power up after a certain voltage waveform, thus we concluded that there is an issue in the supply management.

For ease of test we removed majority of the code, and it remained only the power management, watchdog,  and a heart-beat LED (clock remains default).

On the screenshot of the oscilloscope you can see on channel 1 – the heartbeat and on channel 2 the Vdd supply.

There are 3 voltage dips due to the imperfect connection which we make with the main connector. After the voltage stabilizes the CPU is not running.

We observed that it can power up only with a complete power removal. The RST line does not work, it does not reset the micro.

For the PMM we have tried to set the voltage cores to different levels (0-3) but the results remained the same. 

At this point we do not know how to fix this.

P.S. We have applied patches for errata PMM17,  SYS14, and afterwards we have turned OFF the LDO.

any help is more than welcome

thanks a lot in advance

KR

Vincenzo

  • 0
    Guru 317480 points
    The screenshot did not attach correctly.
  • 0 in reply to Clemens Ladisch
    TI__Mastermind 25676 points

    here we go.

    sorry I forgot it, my bad.

    thanks a lot in advance

    KR

    Vincenzo

  • 0 in reply to Vincenzo Pizzolante
    TI__Mastermind 25676 points
    We have tried the following tests:
    • Step1 – Add high frequency suppressor (100-1000pF): 330pF on both input and output of LDO – No Improvements
    • Step 2 – Add small ferrite between the Cout of the LDO and the CVcc of the MCU - No Improvements
    • Step 3 – Add 2.2 Ohm serie on input of LDO (Rin=2.2Ohm, Cin=220uF + 100nF + 330pF) - No Improvements
    • Step 4 – Replace the 2.2Ohm series on input with 100 Ohm (Rin=100,Cin=220uF) - No Improvements
    • Step 5 – Replace the 0.51Ohm series on output with 100 Ohm (Rout=100, Cout = 3*10uF + 3*100nF + 330pF) – No improvements
    • Step 6 – Add 100uF output cap (Rout = 100 Ohm, Cout = 100uF + 3*10uF + 330pF + 3*100nF) - No Improvements
    • Step 7 – Replace 100uF output cap with 1000uF (Rout = 100 Ohm, Cout = 1000uF + 3*10uF + 330pF + 3*100nF) - No Improvements

    After all this filters we still have the issue present. As we could observe, for step 6 and 7 the phenomena is more hard to replicate, but it is still present.
    Any further recommendations on what we should try?
  • 0 in reply to Vincenzo Pizzolante
    TI__Genius 10860 points
    Hi Vincenzo,

    thanks for the detailed description of your issue.
    I have a couple of follow up questions which can help us to further pin down the root cause:
    1) You describe the issue as hang-up at startup. Does this mean that the voltage dips are only seen during startup of the power supply or do you also see the MCU hanging up after it had previously started up porperly?
    2) Have you implemented the SVS and SVM? If so, could you share the settings with us?
    3) You say " The RST line does not work" - thereby you mean the internal reset circuitry, correct? Or do you apply an external reset which doesn't reset the MCU?

    Thanks for clarifying and best regards,
    Britta
  • 0 in reply to Britta Ruelander
    TI__Genius 10860 points
    Hi Vincenzo,

    As I didn't hear back from you I assume that your issue has been solved in the meantime.
    I'll be closing this thread due to inactivity, please respond back in case further assistance is needed.

    Best regards,
    Britta

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