TMDSDCDCLEDKIT: TMDSDCDCLEDKIT (Design Example)

Hi MW,

The kit you have has multiple power conversions processes:
DC input -> SEPIC -> Multiple PWM switched LED strings

The kit software then controls these stages.  You don't really get a choice in experimenting with buck or boost (they aren't on the board)

At this point, it likely makes sense for me to also make you aware of the TMDSRGBLEDKIT & BOOSTXL-C2KLED, as well.  If only for future readers.

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Your message seems to suggest you're looking for how to design a power system to control LEDs. 

For this, any answer I could provide could be valid.  What needs to be defined is what your end-product's specifications are.  For instance, you'll need to define you input voltage, you'll need to define how many strings you want to control and how long the strings are (which will define the output voltage needed). 

Some other things to think about:  Is dimming necessary (if not, then a digital solution may not be cost-competitive), how much flicker is acceptable (may affect switching frequency you'd choose), how much can color shift while dimming (may affect whether PWM switched LED strings is needed vs whether controlling the string directly by a buck/boost/etc is acceptable), and at what efficiency (may effect whether a buck topology or a more complex LLC resonant topology may be required). 

All these things will affect your choice in topology.  This should give you an idea on some of the considerations, but keep in mind that the C2000 team is not an expert in the field of LED control - and therefore you'll likely need to do your own analysis & research on the topic.

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With regard to compensator design, we manually tuned the loops in the example software we provided (and do not have simulation models available).  You'd need to develop/create simulation models in order to tune the loops in a more methodological way.  Furthermore, the SFRA analysis tool used in some of our more recent kits could potentially be used to assist in this.


Thank you,
Brett

Hello Brett,

                    Thank u for ur kind response, as u said that the KIT only have SEPIC power stage. As per my information SEPIC stage can also perform BUCK or BOOST operations, could u please tell me if any example available? I mean using Control SUITE and CCS to control the current of LED string using programming. Because GUI only provides a manual operation not a programmable solution.

Many Thanks

M W Umar

Hi MW,

The only software we provide for this kit is the one inside controlSUITE (and the older version of this software, which I provided you offline).

In this software, the SEPIC is used to generate a controlled output voltage.  FETs in series with various LED strings are then used to try and output a controlled average current.  Since the device is programmable, you could experiment with other approaches though.


Thank you,
Brett