Hi, I'm trying to power an LCD backlight LED with a current source and control it with PWM. I was considering the LM3405 but now I may have to change over to LM3406 (due to increased current Requirements)
The problem is that my led backlight source/sink needs to be universal, work with multiple LCD's with different LEDs (currents requirements from 200mA to 1.2A) which need to be plug and play, without having to change a drive resistor .
From reading the datasheet, I want to say that the device does not support that as it only allows for a fixed current output. Am i correct in thinking this ? (that the output will source that current but increase the drive voltage to compensate for the impedance of of the LED)
Could anybody suggest a way to do this, make a marginally univeral LED backlight driver for a range of LCD's requiring varying currents (200mA to 1200mA) ?
Thanks in advance for your help