• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 3 answers
  • Subscribers 63 subscribers
  • Views 370 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.

Questions about UC2909

hongwei duan
Intellectual 450 points
Other Parts Discussed in Thread: LM3478, INA139, BQ24610, TPS40210

Hello, I have a project, my input power supply 24V, charging for 28V lead-acid battery, charging current 3A, I would like to ask what is better advice? And when I add a boost circuit in front of me, can UC2909 meet my requirements, I would like to ask if there are any better suggestions?There are also matters needing attention when charging lead-acid batteries, and whether TI has relevant documents.

  • 0
    TI__Guru**** 166826 points
    Hi,

    Unfortunately, we are in the process of discontinuing the UC2909. We cannot modify our 24-V max single charge IC for charging a 28V lead acid battery.

    The app note www.ti.com/.../slva437 shows the charge profile for a lead acid battery and conceptually how to modify a LiIon battery charger to charge a lead acid battery.

    All dc/dc converters provide the constant voltage portion of charge. But you will need to add more circuitry to get the constant current portion of the charge cycle. If your ICs do not have to be medical reliability rated, I recommend searching for a high voltage boost controller (e.g. LM3478) that provides input current limiting or adding input/output current control using an external sense resistor and differential amplifier like INA139.

    Regards,
    Jeff
  • 0 in reply to Jeff F
    Intellectual 450 points

    Hello Jeff,

    my project is the power supply of the medical industry. I would like to know if TI has lead-acid batteries, charging schemes, charging to 28V charging chips.

    I also have a project input of 18V, rechargeable battery 16.8V. I would like to think if the power fluctuation of 0.1V can be filled, we are using your BQ24610 to do this project. If you feel inappropriate, do you have a recommended charging chip?

  • 0 in reply to hongwei duan
    TI__Guru**** 166826 points
    Hi,

    The BQ24610 is a buck charger meaning it needs an input voltage higher than its output voltage. Its maximum operating input voltage is 28V, which means it can only charge a battery up to to about 26V. The TI battery charge team does not have a single IC battery charger that can charge up to 28V. I still recommend a multiple chip solution using LM3478 and one or more INA139 chips to build a discrete battery charger.

    Regards,
    Jeff
  • 0 in reply to Jeff F
    Intellectual 450 points
    Hello Jeff,
    I would like to ask how the high-voltage boost controller (such as LM3478) uses external detection resistors and differential amplifiers (such as INA139) to provide input current limitation or increase input/output current control. Is there any specific documentation to refer to? And if I use the high-voltage booster TPS40210 to boost the voltage, plus INA139, how can I achieve it? Do you have any specific documents for me to refer to?
  • 0 in reply to hongwei duan
    TI__Guru**** 166826 points
    Hi,

    I have been unable to find documents. The concept is as follows. The boost controller provides the constant voltage (CV)regulation as designed. If you add a series sense resistor, sensed by INA139 or similar) to measure either the charge current or the input current, the output of the INA139 provides the constant current (CC) sensing. If configured properly, the output of the INA device drives the controller's feedback pin voltage close to its regulation point when the max charge/input current is reached, thereby providing constant current regulation.

    Regards,
    Jeff