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Bidirectional buck boost dc dc converter for charging and discharging the batteries

I see LT8708 and LT8708-1 are the only bidirectional buck boost converters with DC2719A evaluation boards 

I want to use bidirectional buck boost converter for charging and discharging battery. Two converters are connected in a parallel with different batteries are connected at the output terminals of the converter. I planned to design a control system using Microcontroller using voltage , current sampling circuits and ADC. I generate PWM using Microcontroller to control the output of the converter boards. As I was connecting the boards in the parallel I use current sharing method.

But I see the output control of the DC2719A is controlled by Master slave communication technology.

Is it possible to control the output of the board by using external PWM control using Microcontroller?

If not is there any possible way to do it. Please inform me 

Thanks and Regards

I am uploading some figures for easy understading.

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  • Micro controls DAC (digital to analog converter), DAC output to FB pin or IMON pin. A micro needs to support the serial communication of the DAC selected. Select a voltage output DAC to feed the LT8708 FB pin through a resistor to control output voltage. Select a current output DAC to feed the desired IMON pin on the 8708 to control current.

    If you prefer to use a PWM output then an RC filter or op-amp integrator will be needed to remove the ripple.

  • Hi  I have a few follow up questions to your response above:

    1) Why is a voltage output DAC recommended for the FB for voltage regulation? Should it instead be the LTC7106 which is a current output DAC?

    2) I want to have 2 DACs - one for dynamic voltage control and one for dynamic current control. Do you control if you're in CC or CV mode by adjusting the one you want to control to it's desired value and then increase the value of the other variable to ensure that it is not the limiting variable in the control. i.e. I want to be in CC mode, so set current to what I want and then set voltage setpoint plenty high to sure it never limits?

    3) My application is NiCd batteries. I want to build generic hardware capable of a wide range of voltage and current and then use a microcontroller to adjust the DACs. Each customer or battery would get its own charging profile and this would define a unique part number based on software. I am guessing that 250W is a practical limit for each phase of the buck-boost. For the batteries I want to charge, I would need 5 to 6 phases. Will one LT8708 work well with 5 LT8708-1s. And what is the current output accuracy that I can achieve?

    Thanks,

    Brian