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Q: TLC59108F Design by 1294176
We're looking at using the following part on a new design and I'd like some apps information:
http://focus.ti.com/lit/ds/symlink/tlc59108f.pdf
The datasheet doesn't show how LED's would be hooked up. Do they need a limiting resistor in series or is this all done by the IC ?
The application is a bar-graph driver where we can set the value over I2C. I think this part is a good fit but if you have any other choices, please let me know. We're looking at driving 8 LEDs at the moment.
A: Re: TLC59108F Design by 10449
The TLC59108F requires resistors to set the LED current. This makes LED brightness a function of LED forward voltage drop, LED supply voltage level, and resistor tolerances. The TLC59108 (non F version) is a constant current driver. Another option would be the TLC5917. It drives 8 LEDs with a constant current, regardless of LED forward voltage drop and LED supply voltage.