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UCD3138: SW programming

Part Number: UCD3138

Hi team,

We are planning touse UCD3138 in 2 applications:

1.48V to 30V/60A, CC & CV mode;

2.48V to 100V/1A, CC & CV mode;

And we have 2 questions on UCD3138:

1. GUI can monitor the power supply condition, but can GUI change the parameter of UCD3138, so that we don't need to change the code through CCS?

2. Can GUI generate code directly, so that customer doesn't need to do the software programming?

3. Do we have UCD3138 software design application note or instructions?

Thanks!

  • The GUI can change limited parameters of the TI EVM codes.  Most of the codes permit changing of the filter parameters for the digital compensation filter.

    Often things like dead times, Vout levels, and various fault and warning levels can be changed.  

    The GUI can sometimes generate code for writing those parameters.  Otherwise it cannot generate code.

    The main software design manual is called the Technical Reference Manual.  It is here:

    This document primarily covers the UCD3138, the first chip in the family.  The other chips are very similar, but they all have various enhancements.  The biggest enhancement is to all of the A version chips.   Most of these enhancements are covered in the UCD3138A migration guide here:

    There are also migration guides or programmer's manuals for all the other chips in the family.

    In addition, there are EVM codes provided for an ever growing number of power supply topologies.  These not only provide examples of general programming of the UCD family, but, more importantly, they show how to configure the UCDs powerful state machines to run the power supply compensation loop and fault detection with minimal or no software overhead.  Even if you are doing a new topology, we strongly recommend starting with the closest thing you an get in an existing EVM code.  

    Since the UCD is intended for high voltage, high current isolated systems, most of our EVM codes are for stepping voltage down, we do have a bidirectional power supply that has a step up mode.  This may be the best place for you to start:

    https://www.ti.com/tool/TIDA-00653

  • Hi Ian,

    Thank you for your very detailed reply!

    One data customer want to know but I can't find in the datasheet, is that the current accuracy under constant current mode? Can you help me with this?

    Besides, I saw it from GUI that we can design the output voltage and current of UCD3138, so I suppose we can adjust current and voltage via PMBus?

    Thank you!

    Gary 

  • The current accuracy under constant current mode is a very complex thing to determine, depending on the specific topology, hardware, control loop coefficients, test specification, and manufacturing tolerances.

    If you are at the full range of the EADC, your system is very quiet, and you have easy transient requirements, your current accuracy in constant current could be very good.  If you system is noisy, you're not using the full range of the EADC, and you have to have very high bandwidth on your control loop to handle fast transients, your constant current accuracy will probably be lower.  

    You can certainly change the output current and voltage via PMBus, however for a new topology with different resistor dividers and different voltage ranges, you will have to change the coefficients in the firmware to get the correct translation from voltage and current as measured by the ADC to actual voltage and current reported to the PMBus.  

  • Hi Ian,

    Thank you, your answer is really detailed!

    But as I'm lack of high power DCDC knowledge, and customer wants to realize 48V buck to 30V/60A with constant current and constant voltage mode. Which topology do you recommend?  Do we have such high power demo or examples?

    Thanks!

    Gary

  • Hi, Gary,

    If it is non-isolated converter, use two phases interleaved buck converter.

    If it isolated converter, use hard-switching full -bridge converter.

    You can take TI EVM  as a starting point:     Using the UCD3138HSFBEVM-029 (Rev. A)

    Regards,
    Sean

  • This thread has been quiet for a while, so I'm going to try to close it.