Mp3378e Protection Pin Upd Official

The UPD (Protection) pin on the MP3378E is a powerful, flexible safety feature. By understanding its 1.22V threshold and 5µA internal pull-up, you can implement external over-temperature, over-voltage, or custom fault detection with minimal components. However, proper PCB layout—shielding the UPD trace from switching noise and adding a small filter capacitor—is essential to avoid false triggering.

The MP3378E integrates multiple protection modes to safeguard the IC and the LED strings from damage: mp3378e protection pin upd

[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 UPD (Protection) pin on the MP3378E is

This often indicates the OVP is triggering. Check if an LED string is disconnected or if your OVP resistor divider is set too low for the required output voltage. Stable operation