• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 208 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TPS54A20: ennable mgt

yves gagniere
Intellectual 1695 points
Part Number: TPS54A20
Other Parts Discussed in Thread: UCD90160A

Hi ,

In my design the ennable pin of TPS54A20 is driven from a GPIO of another power device as below:

TPS54A20 ennable  is driven from a device that can start after the 12V power supply of TPS54A20 is established. Because of this TPS54A20 ennable pin is floating and the TPS54A20 can start before the driving device is in function.

Would the below workaround with a pull down on the ennable pin will be OK as it is supposed to block the start of the TPS54A20 until the UCD90160A apply a 0 to 1 transition?

Is there any specific I should take care with such implementation?

Thanks

  • 0
    TI__Mastermind 35115 points

    Hi ,

    This is a good solution. You would just need to make sure the resistance is small enough to pull the EN pin down with the 4-µA internal pull-up current so that it turns off when the UCD90160A output is high impedance. With the ~1.2V threshold and typical 4-µA current source the resistance just has to be <300kΩ. To add some margin to account for tolerance of the device I suggest <100kΩ so 10kΩ is definitely small enough.

    Anthony