• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 123 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.

USB-PD-CHG-EVM-01: BQ25798 and TPS25750

Abdolsattar Rahmani
Prodigy 20 points
Part Number: USB-PD-CHG-EVM-01
Other Parts Discussed in Thread: TPS25750, BQ25798, TPS25751

Tool/software:

I want to use the schematic of this evaluation board for my device, which is battery-powered. I plan to use these two chips(BQ25798 and  TPS25750) for managing the battery charge and then using the charged battery to supply power to my device.

I have a few questions and would appreciate some clarification:

1. To use battery power for my device, can I use the SYS output?
2. Since the I2C lines of these two chips are connected together, how can I access each chip individually with my µC?
3. My device requires a 24V, 1A power supply, and I use a 3S battery. Is it possible to configure the SYS output to 24V and directly connect my device to this output?
4. When the charger is not connected through USB Type-C, can I use the 5V output?



  • 0
    TI__Intellectual 875 points

    Hi Abdolsattar,

    Abdolsattar Rahmani said:
    1. To use battery power for my device, can I use the SYS output?

    The device (load) that you want power should be connected to the SYS pin.

    Abdolsattar Rahmani said:
    2. Since the I2C lines of these two chips are connected together, how can I access each chip individually with my µC?

    You could talk with each device individually as they have unique device addresses. For example, the BQ25798 has a device address of 0x6B.

    Abdolsattar Rahmani said:
    3. My device requires a 24V, 1A power supply, and I use a 3S battery. Is it possible to configure the SYS output to 24V and directly connect my device to this output?

    For BQ25798, 23V is the absolute maximum rating for the SYS pin. V(SYS) varies from MINSYS voltage to slightly above VREG. For 3S, VSYS would be between MINSYS (9V) to slightly above VREG (12.6V).

     

    Abdolsattar Rahmani said:
    4. When the charger is not connected through USB Type-C, can I use the 5V output?

    A bit confused by this question. What do you mean by 5V output? 

    Best Regards,

    Jibin

  • 0 in reply to Jibin Biju
    Prodigy 20 points

    Hi Jibin, 

    Thank you very much for your answers. They were perfect. Please confirm if I am correct: Is it possible to connect the TPS25750 to my microcontroller (µC) through the I2CS pin and configure this chip? Since this chip is connected to the BQ25798 through I2CM, it can configure the Buck/Boost converter and log the configuration to EEPROM.

    For my device, I can use a boost converter to change the output of SYS to 24V. Do you have any suggestions?

    About this question: "When the charger is not connected through USB Type-C, can I use the 5V output?"
    I want to know when the charger is not connected to the chip via USB Type-C, what is the voltage on VBUS on the USB-C?

    Thanks

     



  • 0 in reply to Abdolsattar Rahmani
    TI__Intellectual 875 points

    Hi Abdolsattar,

    Abdolsattar Rahmani said:
    Is it possible to connect the TPS25750 to my microcontroller (µC) through the I2CS pin and configure this chip?

    This would be from the PD team, looping them in. 

    Abdolsattar Rahmani said:
    Do you have any suggestions?

    I'd recommend a boost converter after the SYS pin to bring the voltage up to 24V.

    Abdolsattar Rahmani said:
    when the charger is not connected to the chip via USB Type-C, what is the voltage on VBUS on the USB-C?

    To clarify, are you asking about VBUS on the BQ25798 when the adapter is disconnected?

    Best regards,

    Jibin  

  • 0 in reply to Jibin Biju
    TI__Mastermind 19175 points

    Hi Abdolsattar,

    Jibin added me to help support your USB-C PD controller questions.

    The first thing I would like to note is that we do not recommend the TPS25750 for new designs, and recommend using the TPS25751 instead. It is a p2p and feature compatible part.

    https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1346998/faq-tps25751-migrating-from-the-tps25750-to-the-tps25751?tisearch=e2e-sitesearch&keymatch=tps25751#

    The responses that follow will address the TPS25750, but are also applicable to the TPS25751 unless I indicate otherwise.

    Abdolsattar Rahmani said:
    Is it possible to connect the TPS25750 to my microcontroller (µC) through the I2CS pin and configure this chip? Since this chip is connected to the BQ25798 through I2CM, it can configure the Buck/Boost converter and log the configuration to EEPROM.

    Yes, you can connect an mcu to the TPS25750 I2CS lines. If you want to communicate over I2C through the TPS25750, you should use the "I2Cw" and "I2Cr" 4CC commands described in the TRM.

    Abdolsattar Rahmani said:
    I want to know when the charger is not connected to the chip via USB Type-C, what is the voltage on VBUS on the USB-C?

    If there is nothing connected on the type-C port, VBUS should be 0 volts.

    Thanks and Regards,

    Chris