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TPS65219: TPS6521904RHBR

chakradhar pentyala
Prodigy 10 points
Part Number: TPS65219
Other Parts Discussed in Thread: TPS22965,

Hi team,

we are working on the "TPS6521904RHBR" to power up the AM6X processor with DDR4,we are unbale to power the processor due the PMIC is not working, 
the following are the testing observations.
EN/PB/VSENSE-----is pullup with sw option (high 3.3V)
MODE/RESET-------is pullup(high 3.3V)
MODE/STBY-------is Pullup(high 3.3V)
GPIO2----------------is Pullup 10K 
  we had observed the GPIO2 signal still LOW and PMIC output voltages all are in 0V,
as per the datasheet the marking of the device should be as shown in below
we are seeing marking P219XX on the device ,we have doubt on the NVM loading since we haven't observed GPIO2 High this first step for the power sequence of the PMIC.
please find the attached PMIC schematics. Kindly let me know any other information is required.
thanks & regards,
chakri 4087.PMIC.pdf
  • 0
    TI__Mastermind 22441 points

    Hi,

    Thank You for using E2E! Please find my feedback and questions below.

    • "P219XX" is a generic top marking used for pre-production samples. Once the TPS6521904 is released, then production material will have the top marking you saw on the data sheet. 

    • All Buck converters on TPS6521904 are configured as quasi-fixed frequency and high bandwidth. This configuration requires a minimum of 30uF of local capacitance (47uF is typically used). Buck3 shows 14uF in the schematic (0.1uF+4.7uF+10uF).     

    • LDO3/LDO4 share the same input pin and require a typical of 4.7uF on PVIN_LDO34

    • These are just observations but should not prevent the PMIC from powering up. Could you share a power up sequence showing the following signals:
      • VSYS (VCC_3.3V_EXT)
      • GPO2 (PMIC_TPS22965_EN)
      • Buck2 (DVVD_1.8V)

    Thanks,

    Brenda

  • 0 in reply to Brenda Diaz
    Prodigy 10 points

    Hi Brenda,

    thanks for the quick response, please find the below images for  

    • VSYS (VCC_3.3V_EXT)
    • GPO2 (PMIC_TPS22965_EN)
    • Buck2 (DVVD_1.8V)

     

    • blue probe is VSYS and Yellow probe is GPO2

    yellow is GPO2 & Blue is Buck2 (DVVD_1.8V)

    Blue is Vsys & Yellow is Buck2 (DVVD_1.8V).

    the PMIC is trying to powerup and going to sleep mode.

    thanks & regards,

    chakri

  • 0 in reply to chakradhar pentyala
    Prodigy 10 points

    Hi Brenda,

    can you please help us on the below point from the datasheet page no 30

    "In case the sequence is interrupted due to an unmasked fault on a rail, the device powers down. The TPS65219 attempts to power up two more times. If both of those re-tries fail to enter ACTIVE state, the device remains in INITIALIZE state until VSYS is power-cycled. While it is encouraged to keep this retry-counter active, one can disable it by setting bit MASK_RETRY_COUNT in INT_MASK_UV register. To disable the retry-counter, set bit MASK_RETRY_COUNT in INT_MASK_UV register. When set, the device attempts to retry infinitely."

    seams the device is in INITIAL STATE only as per the observation ,kindly help to bring the device in ACTIVE state.

    thanks & regards,

    chakri

  • +1 in reply to chakradhar pentyala
    TI__Mastermind 22441 points

    Hi,

    Thanks for sharing the scope captures! They show the PMIC shuts down its rails approximately 20ms after Buck2 is enabled. If we compare this data with the power-up sequence on the TRM (see page #8 at the link below), it matches the timing between Buck2 to nRSTOUT. Based on this, we can say the issue starts happening after the PMIC completes the power-up sequence, right after nRSTOUT goes high. 

    TPS6521904 TRM: TPS6521904 Technical Reference Manual (Rev. A)

    Here are my questions:

    • Do you see the same behviour on the remaining PMIC rails? Do they turn On for a few miliseconds and turn-OFF again?
    • How are you driving the MCU_PORz on the processor?
    • Is LDO2 unused? Could you confirm R292 is not installed?
    • What is the output voltage on Buck1 when it turns ON for a few ms? 
    • Could the full schematic be shared with us through private E2E message?

    Thanks,

    Brenda