Hi everyone
I'm going to use STLD40D Driver IC for my TFT LCD. For driving LCD backlight, I'v chosen this Driver from ST. But I can't figure out the function theory of this driver.
could you please explain for me the STLD40D function theory and how to use that?
thank you in advance.
Well, the STLD40D is a boost converter. The function is also described in the data sheet, section 5.1.
It must be taken into account that the converter not only has a min off time, but also a max on time.
The switch-on moment is particularly interesting: initially there is no FB signal, so the power stage is switched on (SW to GND), which charges the boost inductor. As there is not yet enough output voltage to drive a current through the LEDs, pin FB remains zero. However, the max on time now kicks in and switches the power stage off again, whereby the energy stored in the boost inductor is delivered to the LEDs at a high voltage and results in a corresponding current and a signal to FB. From now on, FB can regulate normally.
Does it answer your question?
Regards
/Peter
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