LED constant voltage and constant current help

tonytong

LED constant voltage and constant current help [Copy link]

I'm working on LED recently. The secondary side control is BCD's ap4313, which is a constant voltage and constant current chip. The constant voltage is of course achieved through the bandgap voltage divider, and the constant current is of course achieved through the selection of current limiting resistors. All of this is nonsense. What I'm curious about is: the outputs of its two op amps are connected together, so only one op amp should work. Is there a detection circuit to make it constant current first, and then constant voltage? ? ? ? Similar chips include ST's TSm103. I hope to give you some advice, thank you!