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TMDSHVMPPTKIT:Technical Support Queries for operating board

Jihun Ha
Prodigy 10 points
Part Number: TMDSHVMPPTKIT


Hello, 
I am Jihun Ha, a Ph.D. Candidate under professor Youngjin Kim in the Energy ststems lab at POSTECH.
I would like to get technical support for the TMDSHVMPPTKIT we purchased, which seems to be broken.
Our questions are as follows.

Technical Support Query 1:

We consistently observe the DC-DC converter operating at the maximum current (Isc) of the PV simulator. Upon investigation, we've identified continuity between two input terminals (Vin+ and Vin-ret) only when voltage is supplied in the circuit. Additionally, there is continuity between the Source and Drain of the MOSFETs. To resolve this issue, we seek guidance from TI support to suggest a testing procedure. This will help us determine whether the MOSFET or the Driver IC needs replacement. We appreciate your assistance in providing clarity on the appropriate course of action.

Technical Support Query 2:

In our TI DC-DC converter, the output LLC filter circuit is not functioning, despite obtaining output from the interleaved Boost converter. While connecting the boost stage to the filter stage, we do not observe the expected output. Notably, the magnitude of LLC filter-switching pulses consistently fluctuates between 1.5 V and 3.3 V, although the pulse width remains constant for time 'T'. We kindly request guidance on necessary steps to rectify the continuity issue in the LLC circuit, enabling it to be connected to the Boost stage.

Technical Support Query 3:

The input voltage sensor (Vin-Fb) is not functioning as expected (no reading of 3.3V). However, the input current and output voltage sensors are operating correctly. We would appreciate it if the TI team could suggest adjustable resistors in the sensing unit that could be changed to address the issue. Your assistance in resolving this matter is highly valued.

 We kindly request you to check it out and let us know the solutions.

Thank you in advance.

  • 0
    TI__Genius 11955 points

    Q1.  We suggest that you can send the board back and get a replacement. Otherwise, you can change both the MOSFET and the gate driver. Because when the MOSFET gets bad, it also take the gate driver down with it.

    Q2. Seems like 3.3V bias supply is not working. You can debug that circuit or you can change the board and get a new one.

    Q3. Check the volt at Vin_fb point. And then check it again at ADC input pin where this signal is tied to the ADC pin

  • 0 in reply to Shamim Choudhury
    Prodigy 55 points

    Dear Shamim,

    This is Dr.Ram, working in the same lab of MR.Jihun. Firstly, thanks a lot for suggesting us the possible solutions. 

    Regarding Q1, and Q2, As we heard from TI that our warrenty period got over, do we still have a possibility to excahnge them? your kind suggestion will help us. 

    Regarding Q3, We actually have two TI boards. Among which, one borad reads the sensor values accurately (all sensors); however, the input sensor (Vin-Fb) in  other one always read a constant value. Although, we can see Vo and Iin sensors working perfectly. To ensure its functionality, we also crossverified the sensor output voltage manually, and we could see the voltage varying from (0-3.3 V) for the given input voltage . Despite this, I also exchanged the F28035 controller, and verified them again. Nevertheless, the problem with reading the value from input sensor remains the same. I suspect the problem in dock station of controller, do you have any suggestions to check them? 

    Regards,

    Dr.Ram

  • 0 in reply to Prasanth Ram Jothikumar
    TI__Genius 11955 points

    I am not sure about the warranty question you have. I cannot do anything there. You can try contacting them. If they don't give you a new one you will just have to debug the circuit and replace the bad parts.

    For Q3, you have a good board. Why not you debug the bad board and compare signals with the good ones. Just need step-by-step debugging of the related parts of the circuits in order to find the root cause.