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LM5176: LM5176

Part Number: LM5176
Other Parts Discussed in Thread: MSP430F5529,

I am using an IC LM5176 to charge a battery. How can I use this IC in constant current mode, and that constant current should be controllable through PWM given by Microcontroller MSP430F5529?

  • Hi Rutuj,

    Thank you for considering the LM5176.  The LM5176 has a CC function but it is fixed internally and the setting is determined by the current sense resistor value.   If you want to dynamically adjust the CC, you should consider to use an INA device, and use an external op-amp and let MSP430 to generate a PWM signal.  Averaging the PWM signal by a RC filter becomes the CC reference voltage.  Matching the current sense resistor value, the INA device gain, and the PWM duty, you will achieve the CC control.  The concept is shown in the attached picture.

    CC control of the LM5176.vsd

    Thanks,

    Youhao Xi,  Applications Engineering

  • Is there any other solution to this problem, without using INA as described in the circuit diagram, as I'm using an external Current sensor ACS712 which gives analog signal to MSP and by sensing the current and I will be able to control the output current.

    Will the below circuit combination be used :

  • Hi Rutuj,

    INA is just one concept. I am not familiar with ACS712 but if you can send the signal to MSP via a ADC, you should also send the signal from ACS712 to the amplifier where the INA part connects in my drawing. Namely to replace the INA with the ACS712 in that drawing. You can still use the ADC and get the info for your MSP. You drawing to connect the inverting input of the op-amp will never work.

    Thanks,
    Youhao Xi
  • Dear Sir,
    Can u suggest some IC which has all these things integrated?
    My aim is to charge battery through a solar panel with mppt algorithm which should have integrated logic of buck-boost converter circuit and its current limit and output voltage should be programmable, controlled and should have battery charging logic.
    Thanks for answering,
    Rutuj
  • Hi,

    Is it possible to add a pdf instead of the visio file? Thank you?
  • Hi Horst

    Sorry I was travelling last month.  The pdf is attached.  

    CC control of the LM5176.pdf

  • Hi Rutuj,

    You may check TI battery charging products by posting under the subject of Battery Charging, then you post will be directed to the right engineering. The LM5176 is a general purpose buck-boost controller and it is supported by our product line.

    Thanks,
    Youhao