• State Resolved
  • Replies 3 replies
  • Subscribers 63 subscribers
  • Views 68 views
  • Users 0 members are here
Support feedback
Options
Options
Related

TPS65220: Operation of the MODE/RESET pin

Ryu Yamashita
Genius 3570 points
Part Number: TPS65220

Tool/software:

Hi team,

If MODE_RESET_POLARITY in the register is changed during operation, does the RESET operation operate with reference to the current state?
For example
If the pin input is set to Active-High with Low state and logic is changed by I2C, will the pin be reset?
Or does it need to be set High once?

Best Regards,
Ryu.

  • +1
    TI__Expert 6225 points

    Hi Ryu,

    Thank you for reaching out on E2E.

    The polarity of this pin must not be changed after power up.

    Sathish

  • 0 in reply to Sathish Vallamkonda
    Genius 3570 points

    Hi Sathish,

    I am aware of the information you have provided.
    I have one concern.
    When power to control the RESET pin is supplied from a buck (e.g. Buck2: 1.8V I/O), the RESET pin will be in a "Low" state until Buck2 is output.
    If the RESET pin polarity is set to “Low” active when power is applied, will the RESET state be maintained?
    Will 1.8V not be output from Buck2 until the RESET pin is negated, thus permanently preventing the on sequence from being initiated?
    I was going to make a change in the middle of the process to solve this, but I was wondering if there is any other solution to this problem, as it should not be changed.
    I would appreciate a reset disable until all power is turned on if possible, etc.

    Best Regards,
    Ryu.

  • +1 in reply to Ryu Yamashita
    TI__Expert 6225 points

    Hi Ryu,

    The only condition need to be careful is when MODE/RESET pin is defined as RESET with pin polarity is '0' and the pin state is 'L' until Buck2 powers up and WARM_COLD_RESET_C ONFIG is set to 'COLD RESET' ( sequencing down all enabled rails and power up again).

    under such conditions, need to use a pull up voltage that is already available (or could use VSYS) instead of Buck2 output.

    Sathish