• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 166 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

BQ24075: BQ24075 Charge/Discharge behavior with 0V charge function of PCM

Shawn Zhou
Prodigy 90 points
Part Number: BQ24075

Tool/software:

Dear Sir,
We have a question for BQ24075 Charge/Discharge behavior with 0V charge function of PCM.
The system application is if the battery pack has 0V charge function of PCM, could you share the charge/discharge behavior with us?
Thank you.
e.g.
Pre-charge >> 
CC>>
CV>>
Best Regards
Shawn
  • 0
    TI__Guru** 105760 points

    Hello Shawn,

    We will look into your questions and provide a response by the end of the day.

    Sincerely,

    Wyatt Keller

  • 0 in reply to Wyatt Keller
    TI__Mastermind 31510 points

    Hi Shawn, 

    Firstly, to make sure I am fully understanding your question correctly, what do you mean by 'PCM'? 

    When battery is low voltage the BQ24075 checks for short circuit. The charger IC will only source a small amount of current (approx. 7.5mA) until the battery voltage increases above 1.8V. Once VBAT crosses this 1.8V threshold the device enters precharge phase of charge cycle. This expected behavior is described in datasheet section 9.3.5. 

    On BQ24075 battery is allowed to discharge fully to 0% capacity. This charger IC does not have a built in battery under voltage protection.

    Best Regards,

    Garrett 

  • 0 in reply to Garrett Kreger
    Prodigy 90 points

    Hello Garrett,

    Hope you are doing well.

    PCM is battery protection board.

    Because our protection IC support 0V charge function.

    We would like to understand how the BQ24075 operates under different battery conditions.

    Thank you.

    1. Battery voltage = 2.9~3.1 V 

    2. Battery voltage = 1.8~2.9V

    3. Battery voltage = lower than 1.8V

    4. Battery voltage = 0V

    5. Battery voltage = Floating (Open)

    .

    Best Regards

    Shawn

  • 0 in reply to Shawn Zhou
    TI__Mastermind 31510 points

    Hi Shawn, 

    Thank you for the clarification. Please see my additional comments below. 

    1. Battery voltage = 2.9~3.1 V  -> Device is in precharge phase until VBAT increases above typical 3V. Then device transitions to fast charge phase.

    2. Battery voltage = 1.8~2.9V -> Precharge phase. Battery charged at precharge current (10% of fast charge setting)

    3. Battery voltage = lower than 1.8V -> Battery charged in 'short circuit' mode. As described in my last response charge current is approx. 7.5mA

    4. Battery voltage = 0V -> Battery charged in 'short circuit' mode. As described in my last response charge current is approx. 7.5mA

    5. Battery voltage = Floating (Open) -> Device runs battery detection routine, shown in figure 10-3. Battery detection routine is performed until protection IC circuit is closed to reconnect battery to charger IC. 

    Best Regards,

    Garrett