• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 98 subscribers
  • Views 555 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TDA2SG: RSTOUTn release during power up

Lloyd Hwang
Expert 3850 points
Part Number: TDA2SG
Other Parts Discussed in Thread: TDA2

Hello team,

Customer tried two experiments about RSTOUTn

 -1) If RESETn is released before PORz, RSTOUTn outputs 2ms after PORz.

 -2) If RESETn is released after PORz, RSTOUTn outputs 2ms after PORz not RSTOUTn.
According to the power up sequence in TDA2 data manual, RESETn to RSTOUTn delay is 2ms. But based on observation, RSTOUTn comes after PORz not RESETn.

Please make clear which one between RESETn and PORz will make RSTOUTn release during power-up.

The probed plot is attached in PPT file.

Thanks,
Lloyd
  • 0
    TI__Mastermind 20500 points

    Hi Lloyd,

    - PORz pin is a power-on, global cold reset. (i.e. system is being powered)

    - RESETn pin is a global warm reset (system was powered before, no need to reset everything again)

    - RSTOUTn pin allows other ICs in the system to get reset. This pin is asserted (low) on every global reset (warm or cold, software or hardware). The low signal gets extended for some milliseconds.

    In both of your cases 1) and 2), you are issuing a global cold reset. That's why RSTOUT gets deasserted after PORz. (not RESETn).

    Kindly try asserting a warm reset. This can be done by asserting low RESETn while system is running, and then desserting it. You should observe RSTOUT assertion, and deassertion with delay.

    Please note also that Data manual requires RESETn and PORz to be deasserted simultaneously during power-up. Therefore, it is no matter if note (14) says 'delay after resetn' or 'after porz', but in fact it is after PORz , so I will request documentation team to update the note.

    Thanks,

    Stan