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TIDA-00704: TIDA-00704 feedback control for changing charging voltage and current.

Prodigy 180 points

Replies: 5

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Part Number: TIDA-00704

Hi Experts, 

Tried to design a charger using TIDA-00704 (w/o MCU) for 28.8v, 20Ah battery, 

I have two questions
1. How can I control the output voltage and current of TIDA-00704?
via FB pin on U8 or via Vref and Iref of U5 and how to use these pins?

2. Need a troubleshooting manual or checkpoints for TIDA-00704 as it stops charging the battery earlier it starts charging with 31v, 10.5A, 
tried adding a FB of 200mV to 3v for charging the output voltage.

  • Hi

    Thanks for your question about our TI design.

    1. For the charger application, there should be a MCU on the secondary side for the charging management. You can use the MCU to change the Vref or Iref of U5 so that you can control the output voltage and current.

    2. I didn't understand your second question. could you please make it clear?

    regards

    Huixin

  • In reply to Huixin Wang:

    Hi Wang, 

    Many thanks for the reply, hope you doing well.

    1. In the second question, I'm asking while I was connecting the battery with the TIDA-00704, it starts feeding the battery with 31v, 10.9A via J1 terminal, but now its output is 0v only always, although the battery is partially charged so how can I troubleshoot the issue if anything wrong happens with any module of Tida-00704.

    what I did wrong is tried feeding 200mv to 3v external feed to FB pin for controlling the J1's output.
    or I guess something wrong happen with UCC29950.

    2. as you answered, "You can use the MCU to change the Vref or Iref of U5 so that you can control the output voltage and current."
    can you suggest me any dedicated MCU module for the same if TI has any solution?

    It seems only controlling the Vref make the changes in the output of J1 or i have to control both Vref and Iref at a time? 
    and Voltage limits of Iref and Vref?

    Regards:
    Soonu Verma

  • In reply to SoonuVerma:

    Hi Verma,

    1. I think there is something wrong with your circuit if the output voltage is always 0V. My suggestion is you can disconnect the battery and use the Electronic load for debug first. Maybe you can check if the aux power is normal, then whether the PFC is normal (if there is 400V output), then to check the LLC and SR. Based on current information, I can't analyze what the issues is.

    2. For the MCU, you can select a common one. The MCU need to detect the output voltage and current and you can make the charger work in CC or CV mode based on the battery voltage condition. If you want it work in CV mode, you can change the Vref to control the output voltage and the same as Iref. As for the limit, it's decided by your divided resistor used in your feedback circuit.

    regards

    huixin

  • In reply to Huixin Wang:

    Hi Wang,

    I would like to ask a basic question
    like I have set Tida-00704's output on 28.8v via Vref pin,
    so now when the battery potential increases and start touching to 26-27v then will currently start dropping ? as the mode is CV 

    Regards

    Soonu Verma

  • In reply to SoonuVerma:

    Hi Verma

    The charger should firstly work in CC mode until the voltage of the battery reach the Vref of the CV loop. Then the charger changes into CV mode. You can find a lot information on the google about the battery charging curve.

    regards

    huixin

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