• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 530 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.

bq24292i

Perico Eldelospalotes
Intellectual 505 points
Other Parts Discussed in Thread: BQ24292I

First of all thank you for your help. I think I will choose the bq24292i, but I have some doubts that should be cleared up before. These are my questions:

1.-How can I power OFF my system if it is being powered from the battery? Maybe disconnecting BATFET, but then how can I power ON again?

2.- The USB PHY line that goes to the PSEL pin is VBUS?

3.- What is the difference between MAXIMUM INPUT CURRENT and FAST CHARGE CURRENT? I think that the first is the maximum current that should be draw from the power source and the second is the current that will charge the battery if enough current is available form the power source to feed the system and charge the battery, but I am not sure.

4.- In section "HIZ State with 100 mA USB Host" in the datasheet (page 21) states that if the power source is USB with 100 mA and the battery voltage is enough, the battery charger will enter high impedance mode and the system will be powered from the battery. These are my questions:

4.1- If there is no battery, the charger will not enter HIZ mode and will power the system?

4.2- If the battery voltage is ok and enter HIZ mode and meanwhile the battery is discharging to power the system, the charger will wake up and start to charge / feed the system  when the voltage drops?

4.3- If I (with an I2C command) disable HIZ mode, the charger will start to charge the battery / feed the system?

5.- Say the maximum input current is set by the host via I2C to a certain value because I am using certain AC Wall Adapter. This limit is set everytime the entire system is powered on. Now if I change the Wall Adapter and is not capable to supply all the current, the charger will decrease the input current even below the maximum value to mantain the input voltage no matters how small the current should be?

          Thank you in advance.

  • 0
    Intellectual 505 points
    Hello. Nobody could answer these doubts? It will be nice if someone could help!
    Thanks.
  • 0
    TI__Expert 4285 points

    Hello,

    Here are my comments on your questions:

    1. You can turn off Q4 to shut down SYS.

    2. Please refer to Page 2 or 3 in DS.

    3. correct. Both limits may swap position dynamically. For example, if you set up charge current to 2A, but input is limited to 1A. you won't get 2A, but 1A.

    4. 100mA mode was designed to accomodate old USB. New system will consume much larger current than 100mA. Please use with care.

    5. Generally, Yes. if not enough current from input, charger will reduce charging to support SYS.

    Thanks.

    Best Regards,

    Linhong Qin