[System powers on] | v [PROT pin ramps 0V → 0.8V?] ---No---> [Check C_PROT soldering; replace with 22nF-100nF] | Yes | v [VOUT rises. PROT pin hits 2.0V?] ---Yes---> [OVP trip. Increase C_PROT or lower output target] | No | v [Backlight turns on. Stable operation.]
The monitors the boost output voltage through a resistor divider network. If an LED string goes open-circuit, the boost converter keeps driving the voltage up to compensate. Once the OVP threshold is reached, the IC triggers a latch-off state to protect the external components from high voltage damage. COMP (Loop Compensation) Pin mp3378e protection pin upd
: Verify that the high-megohm resistors connected to the OVP pin haven't drifted in value. A drifted resistor artificially lowers the protection threshold, causing false triggers. [System powers on] | v [PROT pin ramps 0V → 0
