| Pin | Function | Latching? | Action | |------|----------|-----------|--------| | | General fault & latch | Yes (latched) | Shuts down boost, requires VCC reset | | OVP | Over-voltage protection input | No (cycle-by-cycle) | Limits boost voltage immediately | | ISET | Current sense threshold set | No | Sets LED current limit | | OUTx | Channel outputs | No (string fault) | Individual string shutdown |
The MP3378E utilizes several pins to trigger shutdowns or "hiccup" modes when it detects anomalies like shorted LEDs or overvoltage. mp3378e protection pin
The PROT pin was monitored with an oscilloscope. A slow 500 mV drop appeared at 28 minutes, then sudden collapse to 0V. Thermal imaging revealed a hot NTC thermistor connected to PROT via a comparator—the comparator output was glitching due to a bad reference voltage. | Pin | Function | Latching