• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 337 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.

TPS65185: TPS651851 VCOM active discharge

Gasper Korinsek37
Prodigy 240 points
Part Number: TPS65185
We're considering connecting VCOM_CTRL to the battery or IO supply as the chapter 8.3.7 in the datasheet suggests, in order to reduce the number of used GPIOs on the MCU. This means that VCOM is enabled on STROBE4 during power-up and disabled on STROBE1 during power-down. The table on page 5 of the datasheet says that when the VCOM_CTRL is pulled low and VN is enabled, the VCOM discharge is enabled.
Since we have the VCOM_CTRL connected to the battery or IO supply, does this mean that the VCOM active discharge is never enabled? In other words, it doesn't really matter if we connect the VCOM_DIS pin to the GND?
  • 0
    TI__Genius 10490 points

    Hi,

    That is correct, if VCOM_CTRL is pulled up to the battery or IO supply, the VCOM active discharge would never be enabled. The input logic low threshold for VCOM_CTRL is 0.4 V, much lower than the device UVLO of 2.9 V. In this case, since the internal discharge feature is not used, it's recommended to leave VCOM_DIS floating. 

    If discharge is still desired, an external resistor could be connected from VCOM to GND, but please keep in mind the VCOM drive current capability specified in the datasheet. 

    Thanks,
    Gerard

  • 0 in reply to Gerard Copeland
    Prodigy 240 points

    Hi Gerald,

    Thanks for the explanation, all is clear.

    Best,

    Gasper