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LMP90100 getting hang

Other Parts Discussed in Thread: LMP90100

Dear Sir,

I am using LMP90100 ADC for our prototype design of temperature profile controller, We are using RTD as temperature sensor. We are communicating with LMP90100. We are getting correct data from LMP90100. The problem we are facing is the ADC is stop responding after sometime, say half, one, two, or may sometime after four hour. I am not able to get data/communicate with LMP90100, once it is stop responding. The only solution is I need to power cycle the LMP90100. I tried resetting MCU; I also tried resetting SPI communication from MCU but not getting any response. I also tried by decreasing RTD excitation current from 1mA to 500uA to reduce internal heating but failed; I must need to power cycle to get response from LMP90100. Please let me know how I can prevent LMP90100 from getting hang.

For Autosoft Solution,

Pravin Patel 9909003025

  • Hi Pravin,

    we haven't never seen this behaviour. We have characterized the devices in extreme conditions (hot) and for several hours to age the parts (the SPI was alway working in during the test).

    What are you using to generate the SPI signals ?

    Can you provide me with the sequence of command you are sending to the LMP90100 ?

    regards,

    Domenico

     

  • thanks for your reply. i want tell you that we have been facing this problem for long. we could not get support from TI.

    finally we change design, we change ADC and completed our project. i share instruction command soon.

    it was working at par, but some time getting hang and stop responding. we tried by reseting mcu without power cycle will not work. we keep mcu ON and power cycle LMP90100 will solve problem. the only solution is to power cycle LMP90100. its major problem, please don't ignore.

  • Hi,
    I am also having the same issue. I am using LMP90100 as AFE of my design of Final year project. Now I am in a great trouble as evaluations are in next week. I am using LMP90100 EVB. Please tell me is there any hardware reset to avoid such things.
    Ayanga
  • Hi Patel,
    Can you describe me on how you apply power cycle ?
    Ayanga
  • Yes sure,

    Let me explain you how I did power recycle, as I been facing this problem for long time, I made another proto board with has facility to power cycle ACD and MCU, and of course to reset MCU, now I had many ways for troubleshooting,

    1. Keep ADC as it is, and reset MCU to initialize SPI communication.
    2. Keep ADC as it is, and Power cycle MCU to initialize SPI communication.
    3. Power cycle ADC and reset MCU to initialize SPI communication.
    4. Power cycle ADC and MCU to initialize SPI communication.

    There is no response from ACD in 1st and 2nd case, it responding in 3rd and 4th case.

    Let me tell you how to call problem again, you need to create noise, for that take two old AC coil operated electrical contactors, take one relay with NO, NC contact, connect both contactors with relay, one with NO and other with NC, make sure that contactors coil’s AC power source and board power supply (AC to DC) source should be same, now run your board and operate relay, in both condition NO & NC one of the contactor should ON, you will see problem in three to four relay operation.

    If still you are not able call problem, then remover noise filter applied to board power supply like MOV, Common Mode Choke, any power noise filter to increase the noise.

    This is the way I found to recall problem, and then I tried to recover this problem from such condition, but there is no way, only the way is power cycle the ADC.

    This ADC will not initialize communication/respond once communication get break.

  • As far as your education project is concern, I think it should be problem of programming, the problem I facing is arise only in very high electrical noise, which is not applicable in your project, I suggest you refer datasheet and example codes.
  • Hi Patel,

     There shouldn't be a problem in the code. Because it worked perfectly with the same board before. I did not changed any.

    Ayanga