• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 100 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.

BQ25798: VSYS Output when Charging with Solar Panel

Egemen Aksoy
Intellectual 895 points
Part Number: BQ25798

Tool/software:

Hello,

In our project we are using BQ25798 for charging 1s5p 3.6V Li-Ion battery.

In our application, our device will wake up at certain intervals and draw high current during those times.

During this process, the device will be connected to the solar panel and will be charged from it.

However, since we are powering the entire system from the VSYS line, and when the solar panel is connected to the VBUS side, the high current demand during the device's wake-up may not be sufficiently met by the solar panel through VBUS.

Is it possible to supply the VSYS from Li-Ion battery while charging with the solar panel? Or is there any solution for our application?

Also, when CE (charge enable) pin is disabled (pulled high) does the IC supply VSYS from battery?

Best regards,

Egemen

  • +1
    TI__Guru**** 165786 points

    Hi Egemen,

    If the input source cannot supply the SYS load, the charger automatically turns on the BATFET between BAT and SYS pins so that the battery supplements the load at SYS.  This means that V(SYS)=V(BAT).  CE pin only disables charge current flowing from SYS to BAT. ILIM_HIZ =GND disables the converter.

    Please note the following:

    1. MPPT feature auto disables if the V(BAT) drops below MINSYS voltage.  

    2. Please review the app note at https://www.ti.com/lit/pdf/sluab26.

    Regards,

    Jeff