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TPS65217CEVM: sleep mode

Don Lawrence
Expert 1315 points
Part Number: TPS65217CEVM
Other Parts Discussed in Thread: AM3358, TL5209, TPS65217,

hi.  i am working on the beaglebone black, which uses the tps65217c pmic.

when i go into sleep mode LDO4 is still active. 

the am3358 processor definitely goes into sleep mode.

i suspect the tps65217c is not going into sleep mode. 

according to SLVSB64I datasheet, section 8.4.1.3 the only thing required is to

pull the pin  PWR_EN low.  No need to change any register.  straightforward

and simple. 

am i missing something?

is there any way to detect or query if PWR_EN was pulled low?

thanks.............dd

  • 0
    TI__Intellectual 950 points
    Hi Don,

    I have forwarded your question to responsible applications engineer. He will answer to your inquiry about the sleep mode, thanks

    Tuomo
  • 0
    TI__Mastermind 30260 points
    DD,

    When you attempt to enter sleep mode, can you confirm that only LDO4 is voltage is still high? All other LDOs and DCDCs are low?

    What is the precise voltage at VDD_3V3A? Note that VDD_3V3B is used as the EN signal for the TL5209 (U4) and VDD_3V3B is used as power for more places on the board (such as the NAND Flash and ethernet transceiver).

    Also, how are you terminating the BAT, BAT_SENSE, and TS pins of the TPS65217 (TP5, TP6, and TP7 on the BBB)?

    Entering SLEEP mode is as simple as pulling PWR_EN low on the TPS65217 PMIC by itself, with you could test on the TPS65217CEVM, and then compare the results vs the BBB board to understand the differences.
  • 0 in reply to Brian Berner
    TI__Mastermind 30260 points

    DD,

    My apologies, I meant to follow-up with this:

    It might be helpful to short BAT_SENSE to BAT and connect this shorted net to GND through a 1-10kOhm pull-down resistor. The TS pin can be left floating.



    This should help in the RESET state more than entering the SLEEP state, but it is one option to ensure the power path is making the intended transitions smoothly.

  • 0 in reply to Brian Berner
    Expert 1315 points
    hi brian. i regret do not have a voltmeter. and i cannot confirm other DCDC/LDOs are up.
    i may borrow a meter, i am but a software monkey and afraid to poke around.

    i have a single cell 1000mAh Lipo on BAT AND BAT_SENSE and a 10k resistor on TS.
    the battery is charging repeatedly. the 10k resistor successfully spoofs an NTC sensor.
    these are all confirmed by correct register state changes in STATUS, CHGCONFIG0 and 1.
    and they have been working for weeks.

    i now have a wifi transceiver ESP8266 connected to LDO4 which remains alive. and i want to kill it.

    when i disable LDO4 by resetting bit 0x5 in ENABLE register, it turns off momentarily then
    turns back on. this happens repeatedly, which makes me think TI has removed the RTC
    only sleep mode feature per the last post in:
    e2e.ti.com/.../2119005

    on the BBB there is an LED on VLDO2 which is starting to behave erratically. sometimes the
    board does not come up and that LED flashes every few seconds. maybe i damaged something.

    so, please advise me if it is safe to probe with a voltmeter. some of these pins are a few mA.
    will a cheap digital multimeter draw too much current?

    thanks............dd
  • 0 in reply to Brian Berner
    Expert 1315 points
    hi brian. you want me to pull down BAT and BAT_SENSE to GND?
    is this a one-time thing?
    i need the battery connected as a UPS and power the RTC when sleeping.
    thanks...........dd
    ps the battery will not charge with TS disconnected
  • 0 in reply to Don Lawrence
    TI__Mastermind 30260 points
    Don,

    No, if you have a battery in your system then I do not advise pulling BAT and BAT_SENSE down to GND.
  • 0 in reply to Brian Berner
    TI__Mastermind 30260 points
    And with a battery in the system, you must have a 10k resistor from TS to GND to "spoof" the PMIC into thinking an NTC is installed that is within the ideal temperature range.


    I recommend you use your multi-meter to measure the voltage on one of the two easily accessible BAT pins.

    If BAT > 3.3V, then you are good (above VUVLO).
    If VBAT<= 3.3V, this could be causing some issues (below or close to UVLO).

    If this measurement does not seem to show anything interesting, then I might need to re-assign your thread to the processor support forum so they can help you debug via software.

    They can always re-assign the question back to me if the PMIC needs to be analyzed further.