• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 64 subscribers
  • Views 253 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.

BQ29330: inquiries

Danilo A.
Mastermind 26750 points
Part Number: BQ29330
Other Parts Discussed in Thread: BQ20Z90, BQ77915, BQ24725

Hi Team,

Our customer would like to use BQ29330 with STM32 Nucleo-Board and has some questions as follows:

- It will be standalone (now without a BQ20Z90 fuel gauge ), I hope this is possible?
- So on Pin WDI can I generate a 32kHz signal from my MCU? And what is the signals purpose?
- Can I use the XALERT Pin for example for a small LED just as an indicator (also on LEDOUT Pin)?
- Is RST Pin any important then?
- And what purpose is PMS Pin?

He already read the datasheet lots of times but these are the functions that he would like to clarify.

Regards,

Danilo

  • 0
    TI__Mastermind 36700 points

    Hello Danilo,

    I would advice your customer to use a different protector IC, like the BQ77915. This is a very old part and support is limited, it may not be supported for very long.

    Regarding your questions, most of these seem to be found in the datasheet:

    • I believe you could use the BQ29330 without the gauge, but it may be more complicated.
    • WDI seems to be the clock used for the timing of OC and SC delays and as watchdog clock. See WATCHDOG INPUT (WDI) in the datasheet.
    • XALERT current seems too small to power-up an LED (~140-uA).
    • See POR and WATCHDOG RESET (XRST) in the datasheet for RST pin behavior.
    • If PMS is connected to PACK, the CHG FET will be used during 0-V charging. See the OUTPUT_CONTROL REGISTER (0x01) register in the datasheet.

    Best Regards,

    Luis Hernandez Salomon

  • 0 in reply to Luis H. S.
    TI__Mastermind 26750 points

    Hi Luis,

    Thank you for your response. We have received this feedback from our customer,

    Like I already stated, we considered not to use a fuel gauge because I find the programming complexity much too high especially without the use of the bqEASY-Software (the modules for programming are just way too expensive).
    So I will try to program only the bq29330 and use external components for SOC-calculations.
    Since this is a prototype for a bachelor thesis and I'm already in the Layout process I cannot switch the chip anymore.
    It would be great if you could give me any kind of documentation or tutorial where I can get a clue of how to write fitting I2C Code for the operation of the BQ29330. Same applies by the way for the Charger IC BQ24725 I am going to use.
    And last but not least, answer the following remaining questions on the BQ29330:
    - What can I use the GPOD-Pin for? / If not used, can it be floating?
    - If not used for precharging as you stated, is it OK to leave PMS-Pin on Ground?
    - If unused, can ZVCHG be floating?

    Since no Fuel Gauge is used, what happens with Pins XRST and REG? Can they be left floating or should they be used otherwise?
    One last question: Since the BQ29330 is used to be operated in a portable application, I guess it's own VCC is coming from the battery cells attached? So the Chip is self-sustained?

    Regards,

    Danilo

  • 0 in reply to Danilo A.
    TI__Mastermind 36700 points

    Hello Danilo,

    As I mentioned, this is a very old part and the people experienced with the part are already gone from the company. We do not have any example codes for this device. I apologize. I believe we usually recommend to use this IC in conjunction with the gauging IC.

    Regarding your questions:

    - What can I use the GPOD-Pin for? / If not used, can it be floating?
    I am not entirely sure what the usage of this pin is for, but you can read the description of this pin and behavior at the OUTPUT_CONTROL REGISTER (0x01) section and the GENERAL PURPOSE OPEN DRAIN DRIVE CIRCUIT (GPOD) section of the datasheet. From these it seems to be another driver that can be used if desired to control another FET, it has a 1-mA drive at 25-V. Seeing the EVM and TRM, it seems like it can be used to drive the ZVCHG FET.

    - If not used for precharging as you stated, is it OK to leave PMS-Pin on Ground?
    Yes, you can connect to GND.

    - If unused, can ZVCHG be floating?
    Yes, this can be left floating.

    -Since no Fuel Gauge is used, what happens with Pins XRST and REG? Can they be left floating or should they be used otherwise?
    If you are using an external regulator for your MCU, then these would not need to be used. I believe you can leave these floating. 

    -Since the BQ29330 is used to be operated in a portable application, I guess it's own VCC is coming from the battery cells attached? So the Chip is self-sustained?
    You are right.

    Best Regards,

    Luis Hernandez Salomon