• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 62 subscribers
  • Views 392 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.

TPS62360 / VIN AND VDD SEQUENCING

Ran Feldman
Intellectual 780 points
Other Parts Discussed in Thread: TPS62360

Hi,

Is there a need to sequence the VDD pin and the VIN/AVIN pin for correct operation of the IC?

For example if I need 0.7V output, should the VDD and programming of the IC be done before applying the Vin voltage?

Thanks.

Ran

  • 0
    TI__Guru**** 151530 points

    No, there is no requirement to have either voltage present before or after the other--this does not violate any maximum rating in the abs max table.  Note that having other signals present (EN, I2C, etc.) may cause such violations of the abs max ratings in the datasheet.

    But per page 26 of the datasheet, the I2C interface is disabled and the part reset if either AVIN or VDD are not present.  So, you won't be able to program the part without both sources there.

    I recommend using the EN pin to keep the part off, until it is programmed to the right voltage.  

  • 0 in reply to Chris Glaser
    Intellectual 780 points

    Hi Chris,

    In this design the TPS62360 is used to power another switcher regulator using the 1.4V default output voltage.

    When the second voltage regulator powers up it provides the 3.3V needed for the VDD pin. So as you can see the idea was to use the default settings to sequence another regulator that will enable the I2C programming.

    My question is, if the AVIN and the enable pin will be powered/enabled will the IC output the 1.4V correctly, and the I2C will be able to program the output voltage when the 3.3V will be applied to the VDD pin.

    Will this configuration work, or should VDD and AVIN be applied together?

    Thanks,

    Ran

  • 0 in reply to Ran Feldman
    TI__Guru**** 151530 points

    I believe so, but let me make sure I am clear on your sequencing:

    Vin/Avin/EN applied.  Vdd off

    IC outputs its preset voltage (selected by the VSELx pins)

    Vdd applied

    I2C changes output voltage to some other value

    The above sequencing works fine.  You can see in figure 40 in the D/S that not having Vdd only prevents I2C communication but does not disable the device.  There is no need for AVIN and VDD to be applied together.