LED backlight circuit, output voltage 51V, each LED current 105ma. The current problem is that the output inductor l546 has been whistling. I try to adjust the FSW frequency and Iset current are useless, what is the solution. The inductance l546 is in accordance with the official recommended model.
LED背光电路,输出电压51V,每一路LED电流105mA。目前遇到的问题是输出电感L546一直在啸叫。我尝试调节FSW频率和ISET电流都没有用,请问有什么办法解决。电感L546按照官方推荐的型号。
Johnsin Tao:
Hi在电感L546的输入端建议加大电容(22uF或者47uF), 因为输入电压会因为输入电容不够而瞬态被拉低,会导致更大的输入电容以及电感峰值电流,可能导致电感饱和而发声。其次确认电感饱和电流是否足够,建议适当加大。输入端的耦合电感其实可以不要。