rsdio tipped us to an app note on a Boost driver for long LED strings.
The long strings of LEDs commonly found in TV and display backlighting, street lights, and parking garage lights require a current driver capable of producing high voltages. This reference design provides such a driver using the MAX16834, and demonstrates how very-high dimming ratios can be obtained.
Thanks rsdio!
I’m so glad that you brought this up (besides also being a fan of Maxim appnotes)…
For a couple months I’ve been trying to get around to doing a constant-current HBLED driver board, but it’s so far down in my pile of things to do. I ‘ve felt like I’ve had to do my own because I’ve got a bunch of goofy LEDs that take weird currents like 240/400/500/800 that I can’t find affordable off-the-shelf drivers for.
So how about a really Dangerous HBLED driver board, namely one with programmable current levels (perhaps with something like an I2C/SPI digipot, or even DIP switches, in a pinch) for the 240-1000mA range? Ultimately the problem that I’d like to solve is for wireless, separately addressible single/short-string HBLED halogen tracklight replacements.
Just a thought…!