When I reviewed TI's new LED controller/driver development kit earlier this week (click here to see the review), the folks who usually brief me were unavailable so I was forced to publish my report with a few open questions that I promised to answer as soon as I could. After my conversation with Charlie Ice, product marketing manager for the C2000 series, I have some answers for you – and some interesting news about a chance to win one of these slick little kits.

My conversations with Mr. Ice were very candid and helped answer any of the open questions I thought would be useful for readers. For those of you who are more visually oriented, TI has produced a very nice video which provides a clear, concise introduction to using the C2000 LED dev kit. Not surprisingly, it is hosted by Charlie Ice, the fellow I talked to. The link to the video was not working when I published the first review but it works now and can be viewed by clicking here.

Please note that the answers I’m posting below are not precise quotes from TI and have been edited for the purposes of clarity, brevity and protection of any sensitive issues that came up during our conversation.

Q1 – What sorts of applications would need the fine-grained dimming and fast response time that the Piccolo processor and its hardware PWM channels can provide? The kit is intended to help familiarize engineers with the concepts digitally-controlled lighting and to assist in the development of advanced LED lighting features like color mixing, compensation for aging elements, and supporting communication protocols used in smart lighting or remote control networks (PLC or wireless).

Q2 – The announcement says that the dev kit supports up to 8 PWM channels but the Piccolo has 14 PWM channels. Is the software capable of running all 14 channels at their maximum resolution, and can the dev kit be expanded to support those additional LED strings? The processor and software support at least 14 channels with plenty of processing power left over that can be used to support things like communication protocols and diagnostic routines that often require a second processor if a less powerful controller is used. The development board has provisions for up to 8 LED channels but there are provisions to access the necessary control signals should a developer want to add additional channels.  .

Q3 – What is the architecture of the high-powered LED driver stage and what are the driver transistors used in the dev kit? The driver circuit consists of low-cost power MOSFET driven by an op-amp that buffers the PWM channels. The Piccolo’s on-chip ADC provides current sensing each channel, enabling precise software controlled closed-loop for more accurate light output and thermal runaway protection. Simple headers on board enable access to I2C bus so designers can add temp monitoring or light output sensing easily.

Q4 - What is the practical range of output power levels that the kit can support, and are there provisions to help developers who want to create drivers that support outputs beyond the kit’s maximum power? The kit’s DC-DC power stage can support up loads of to 50W, but each of the 8 power strings can drive 30W. The kit’s LED board ships with six 6W strings that keep it within the power supply’s limits but it has solder mount points that allow it to be populated with more LEDs at the developer’s discretion. For applications which exceed the on-board supply’s capacity, there are provisions for connection to an external supply.

Q5 – How does the Piccolo stack up as a lighting controller in terms of features, capabilities, and overall solution cost per channel against the formidable competition from products like Microchip Technologies’ dsPIC MCUs and Cypress Semiconductor’s EZColor HBLED contoller? TI makes no direct claims but our conversation centered around their opinion that Piccolo’s PWM and ADC capabilities are more flexible and configurable and have a wider dynamic range than any other solution in its price range. They also say that most other solutions use a 16-bit architecture, have lower clock speeds or both. This means that their processing capabilities, may not be enough to support both sophisticated control of multiple LED channels and other advanced features (such as communication protocols) simultaneously. They also pointed out that the Cypress solution is a fixed-function device with configurable features instead of a fully programmable solution. I’d say that while this could be an advantage in some applications, the EZColor solution does need a separate processor to support communication and any other advanced functions that are not built into its hardware.

 When asked about the kinds of applications that the Piccolo would be best at addressing Mr. Ice said that their target markets included, street lighting systems, billboard lighting, smart lighting systems for commercial, industrial, and even residential use, as well as intelligent backlighting systems for large HDTVs.

About the contest I mentioned earlier - This is a very nice development kit and I was itching to get my hands on one so TI graciously agreed to ship one off to me to play with for a bit. I was thinking of using it to do some fancy mood lighting for the Rumpus Room of Doom (my basement office) but realized that it might be even more interesting to see what some of my readers could do with it. TI has agreed in principle to letting me give the kit away to whichever lucky reader comes up with the best application for it.

It will be another few days until we’ve hashed out all the legal mumbo-jumbo for the contest but so far it looks like there will be only two requirements for entering a description of your application for judging. The first one is that you allow me to pass your contact information on to TI so they can contact you to see if you want any more information on their products. The second one is that, if you win the kit, I’d like you to publish a short write-up on your project on our site.

 I’ll have more details about the contest next week so stay tuned….