• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 883 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.

TPS62230: TPS62230:TPS62237's shutdown mode

Cooper Luo
Prodigy 140 points
Part Number: TPS62230
Other Parts Discussed in Thread: TPS63051, TPS62821

Hi All

In the datasheet of TPS62230, a table named "Device Comparison Table" shows TPS62237's "Pulldown EN, MODE" is no. what does it mean?  Does TPS62237 not support the shutdown mode?

If TPS62237 support shutdown mode, pulling TPS62237's EN pin to low forces the device into shutdown mode, should the Vout equal to 0V? The data we tested showed that when EN pin pulled down, Vout

was 0.5V. Why?

The schematic diagram is shown below.

Thanks a lot !

  • 0
    TI__Guru**** 150670 points
    Hi Cooper,

    Please see the pin functions table on the next page and section 8.3.2 which explains this column.

    This device family does not have output discharge. So, when it is disabled, Vout might remain at some value, if there is insufficient leakage to bring it down.

    Finally, this is an older device. It also looks like you want to make 3.3V from a single cell battery? A buck-boost converter, like TPS63051, will maintain the 3.3Vout to lower battery voltages. Or the TPS62821 buck converter can provide the same function as TPS62237, but with higher efficiency, a PG output, and output discharge.
  • 0 in reply to Chris Glaser
    Prodigy 140 points

    Hi Chris

    Thanks for you reply!

    As TPS62237 has been widely used in our project, we have no intention to replace it at present. However, we will evaluate the new products you recommend and look forward to the appropriate items.

    As TPS62237 don't have the function of output discharge, when the device enters shutdown mode the Vout is not equal to 0V immediately. But when the device is off, we discharge the output with discharge resistance.The output voltage is 0V when the discharge resistance is connected, and the voltage is restored to 0.5v after removing the discharge resistance. Can you help to analyze the reason?Is there any way to keep the output at zero when it is off? Thanks.

  • 0 in reply to Cooper Luo
    TI__Guru**** 150670 points
    If the output voltage rises up to some voltage, when the device is off, something else is your system is leaking onto the output and pulling it up. One such leakage path is through GPIO pins (or pull-up resistors) of an MCU, which are still powered from another system voltage (such as 1.8V) which is not off. You need to either remove this leakage path or sink the leakage current.