Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 64 subscribers
  • Views 372 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.

TPS65011 Shutdown issue

Deon Theunissen
Prodigy 40 points
Other Parts Discussed in Thread: TPS65011

Hi,

We are using the TPS65011 in a design meant to run off a Li-ion battery as well as an external DC supply. We have a bit of an issue when trying to put the regulator in shutdown mode (WAIT Mode) to power our system down.

When only a battery is connected to the system the shutdown function works perfectly without any issues. But when we have the DC supply (via the AC pin) connected as well the TPS65011 shuts off its regulators and then powers up after about 2 to 3ms.

I've followed the procedure as described in the datasheet, which is basically the following:

- Set AUA bit for WAIT mode

- Set the Enable Low_Power bit

- Set the LDO1 OFF bit

- Set the LDO2 OFF bit

- Set the Main and Core discharge bits

- Clear the Enable Supply bit

- Pull the Low Power pin high

We are not using HOT_RESET or RESPWRON pins.

BAT_COVER is pulled high

PB_ONOFF is connected to our power button.

Thanks

  • 0
    TI__Genius 16870 points

    Hi Deon, 

    Can you take a scope shot of the PB_ONOFF and HOT_RESET pins with the VCORE, VMAIN, and LDO outputs? Can you also take a scope shot of AC with respect to this sequence too? 

    For debug purposes only, remove the battery and retry your sequence. 

  • 0 in reply to Michael Green
    Prodigy 40 points

    Hi Michael,

    Thanks for your response.

    Please find attached a photo of the waveforms.

    We only have a 4 channel scope:

    1 - LOW_POWER pin (I'm invoking the shutdown from software as no keypad is connected, thus PB_ONOFF is not shown)

    2 - VMAIN

    3 - VCORE

    4 - AC pin

    HOT_RESET is not used so I cannot scope that pin unfortunately.

    I hope this helps. Let me know if you need other info as well.

    Thanks!

  • 0 in reply to Deon Theunissen
    TI__Genius 16870 points

    Deon,

    1. Can you try increasing the duration that LOW_PWR pin is pulled high for? 
    2. Have you tried this test without the battery plugged in? 
    3. If you are not using PB_ONOFF or HOT_RESET, how do you have them connected? 

    Can you order an EVM and test your sequence on that board?  

  • 0 in reply to Michael Green
    Prodigy 40 points

    Hi Michael,

    1) I will increase this duration and let you know.

    2) For the tests I sent you I did not have a battery connected.

    3) Currently they are both just a no-connect (or open)

    I will see if we can organize a EVM.

    Thanks for the help thus far!

  • 0 in reply to Deon Theunissen
    TI__Genius 16870 points

    Deon, 

    On #3, my concern is that is you leave these pins floating then they can bounce up and down with the noise from the circuitry around it. If they bounce then they could trigger a button pressed detection. This would transfer you out of wait mode even if you asserted AUA bit high. 

    However, if this was the case then I would expect that it would have a false detect only sometimes or at different delays from entering wait mode. Does the duration of the time spent in wait mode ever change or vary?