• State Resolved
  • Locked Locked
  • Replies 11 replies
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 234 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

LM5170EVM-BIDIR: LM5170EVM-BIDIR Lower Cost Alternative

Kartavya Agarwal
Intellectual 500 points
Part Number: LM5170EVM-BIDIR
Other Parts Discussed in Thread: LM5170

Hi,

I am looking to buy an evaluation board for a bidirectional boost converter with current control and integrated gate drivers. The LM5170EVM-BIDIR is perfect for my application.

However, at maximum voltage on 12VDC port, this eval. board can transfer approximately 3kW of Power (60A @48VDC). This is significantly more than the power ratings that I will be testing on this board.

As a result, could you suggest a lower power rated evaluation board that is cheaper and offers the same functionality? A board with maximum power transfer capability of around 1kW would be more than sufficient for my application.

Sincerely,
Kartavya Agarwal.

  • 0
    TI__Guru 68495 points

    Hi Kartavya,

    Thank you for considering the LM5170.  It is a misunderstanding.  The 60A is for the 12V rail and the EVM can support to ~700W.   What is your power level?  You can just use single phase if 700W is still too much.  

    The EVM is built to help you evaluate the LM5170's capability, and you can always scale the circuit down if your need lower power.  

    Thanks,

    Youhao Xi, Applications Engineering

  • 0 in reply to Youhao Xi
    Intellectual 500 points

    Hi Youhaao,

    Thanks for the clarification. That should work. Also, can I perform votlage control at the outputs along with current control? Or can I only do current control using this EVM?

  • 0 in reply to Kartavya Agarwal
    TI__Guru 68495 points

    You can do voltage control, too.  To facilitate your test, you may refer to the attached jumper setting and board modification.

    2450.LM5170EVM-Bidir.pdf

    Thanks,

    Youhao Xi

  • 0 in reply to Youhao Xi
    Intellectual 500 points

    Hi Youhao,

    It seems like the file you attached implies that I can change the voltage reference purely in an analog manner by swapping resistors R77 and R78. Is there a way I can change both current and voltage references dynamically through a micro-controller?

    According to Section 3.5 of the User guide, I am supposed to contact TI to learn about how to operate the EVM through an MSP431 or C2000 MCU. Could you please provide a customer application support contact number or exhaustive documentation that shows how I can dynamically control power flow direction, current reference, and voltage reference through MSP431 for this EVM?

  • 0 in reply to Kartavya Agarwal
    TI__Guru 68495 points

    Yes you can.

    To change the voltage reference, you can remove U13, and feed your PWM to C95 through RC filters. You may consider to use two stage RC filter to attenuate the ripple without causing too much delay.

    To change the current reference, you need to add an additional op-amp circuit and use it to clamp ISETA signal across R86. 

    Please refer to https://www.ti.com/tool/TIDA-01168, and you can also find the firmware at the link.

    Hope this clarifies. 

    Thanks,

    Youhao

  • 0 in reply to Youhao Xi
    Intellectual 500 points

    Hi Youhao,

    Thank you for your response. Moreover, can I use an MSP432 Launchpad to interface with the EVM  to perform this dual current / voltage control instead of MSP431 Launchpad as suggested?

    Or is it best to just stick to MSP431 Launchpad?

  • 0 in reply to Kartavya Agarwal
    TI__Guru 68495 points

    We haven't tested with the MSP432 launchpad, so I am not 100% sure about it, although you should be able to use it.  However, I would strongly to recommend the C2000. Based on our preliminary test a few years ago, we found the approach with MSP431 did not respond as fast as the C200 solution do to dynamic transients.  This is basically limited by the MSP431's clock frequency and limited resources.   

    Thanks,

    Youhao

  • 0 in reply to Youhao Xi
    Intellectual 500 points

    Hi Youhao,

    Are the jumper setting and resistor mounting instructions here to disable outer loop voltage control or to just change the reference in an analog manner?

    If this is true, how can I disable outer loop voltage control on the EVM?

  • 0 in reply to Kartavya Agarwal
    TI__Guru 68495 points

    If you want digital control to handle the voltage loop, you should disable the onboard analog voltage loop.  If you still want to use the analog loop control but you want the MCU to adjust the voltage, then you just need to change the voltage loop reference voltage.

    To completely disable the output voltage loop control on the EVM, you can remove J36.   

  • 0 in reply to Youhao Xi
    Intellectual 500 points

    ok, so which pin on J17 can I use to send a reference voltage signal from the MCU that will be enforced by the implemented voltage loop on the EVM?

  • 0 in reply to Kartavya Agarwal
    TI__Guru 68495 points

    It cannot be accessed through J17.  Like said earlier, you need remove U13, and feed your PWM to C95 through RC.  U13 is the fixed Vref for the EMV, and know you need the Vref to be controlled by MCU.