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TVP5150AM1: TVP5150AM restart after lost lock detection

Part Number: TVP5150AM1

Dear Support Team,

my customer has the following issue: in specific low temp cycles he experiences a lost lock, by monitoring STATUS Register #1;

after this detection he forces a restart, setting power down in Operation Control Mode Register. After a limited (but few s) period during which image is still compromised, the device gets locked and the situation recovers.

Is this a correct approach? Any way suggested to force restart in a faster way?

Please let me know your thoughts.

Thanks


BR


Nicola Cellurale

  • Hi Nicola,

    TVP5150AM1 initialization and start up procedures are described in linked below guides

    www.ti.com/.../slea021.pdf

    www.ti.com/.../slea102.pdf

    but I'm afraid that the restart could not be made faster.

    An other approach is the customer to select industrial temperature grade device instead of commercial but probably this hardware migration will increase the final product price.

    Regards,
    Tsvetolin Shulev

  • Hi Tsvesolin,

    thanks for your feedback. not very clear to me whether the right approach is to set power down in Operation Control Mode Register or perform a SW reset, could you clarify?

    Thanks

    BR


    Nicola

  • Unfortunately, I can not test the issue and have no enough experience with TVP51xx behavior at low temperature operating. Therefore I can not conclude which approach is faster and which approach will be the better solution. I suggest the customer to test which approach it better.

    Regards,
    Tsvetolin Shulev

  • If the device temperature is outside the operating range then the device is not guaranteed to operate. It is recommended to hold the device in hard reset (physical reset pin resetb) until within the correct temperature range. Once the temperature is valid the resetb pin can be de-asserted.

    It may not be sufficient to use the I2C interface to reset the device since the I2C is not guaranteed to operate when outside the operating temperature range.

    BR,

    Steve

  • Hello Steve,

    thanks for your feedback, but why are you talking about outside the operating range? My customerrespects the recommended operating conditions in temperature, specifically at low temps (within recommended range) he experienced the issue...

    this said the unclear point is still: what is the suggested procedure to restart the device after a lost lock detection?

    Thanks for your support

    Kind Regards


    Nicola

  • Sorry for the confusion... I thought from reading the other response regarding using industrial temp range devices that the device was being operated outside its operating range.

    If the device IS within its operating range then you do not need to do anything when lost lock occurs. The TVP will re-lock to a valid signal.

    If the TVP is loosing lock then it implies that the signal itself is somehow getting corrupted, hence the TVP can't lock to it.

    Can the customer check the signal at the device input pin with an oscilloscope to make sure that there is no corruption of the signal feeding in to the TVP?

    Which lock bit did they check? The "lost lock" bit is "sticky" and will retain its setting even when a valid signal is locked, so it should be cleared by reading it.

    Can the customer please check bits 1, 2 & 3 when in the problematic state? These return the instantaneous state of video lock.

    BR,

    Steve