Part Number: LM3434SQ-20AEV
Hello TI-Team,
we are building up a new optic inspection device as a prototype of a new tool. So we bought some LM3434sq-20eav bords to drive LEDs in diverent ways.
First scenario is to drive a single LED with one of these bords. Powering the bord with -12VDC with respect to ground - all works fine.
In a second scenario we would drive a LED-string with the same LM3434sq-20eav bord. Because of the higher forward voltage of the LED-string,
we have to raised the supply voltage to -24VDC with respect to ground. So in a first step i tried to raise the supply voltage to -24VDC with the single
LED connected - but the bord burned. Both driver transistors Q8 and Q9 - have a look at spec - exeeds their power limits. This came as a surprise,
because the manuel suggest a wide supply input range of -9VDC to -30VDC. - What did we wrong? -
