Mp3378e Protection Pin Upd -
: Disabling or altering protection thresholds bypasses critical device safeguards. This procedure should only be performed during diagnostic isolation or when a faulty, aging LED channel needs to be balanced out. Method 1: The OVP Voltage Divider Bypass (Universal Fix)
| Protection Feature | Function Description | Related Pin(s) | Notes | | :--- | :--- | :--- | :--- | | | Monitors boost output voltage; if too high (e.g., from an open LED), it shuts down the controller to prevent damage. Disabled at startup if OVP voltage is < 75mV. | OVP (dedicated pin for external resistor divider to program OVP threshold) | Programmable; often set by an external resistor divider. Active during startup to check for shorts. | | Over-Current Protection (OCP) | Monitors inductor peak current; if excessive (from short circuit or overload), it terminates switching cycle. | ISENSE (senses voltage across external current-sensing resistor RSENSE) | Cycle-by-cycle limiting for immediate fault response. | | Under-Voltage Protection (UVP) | Shuts down the WLED controller if VIN1 drops below operating threshold (e.g., 6.5V), ensuring proper operation. | VIN1 (supply input) | Prevents erratic behavior during power brownout. | | LED String Open/Short Protection | Monitors current in each of the four LED strings; if an open or short occurs, it disables that channel to protect other components. | LED1 , LED2 , LED3 , LED4 (sink pins for each LED string) | Dedicated to protecting LED array and current sources. | | Thermal Shutdown (OTP) | Monitors internal IC temperature; shuts down controller if temperature exceeds safe limit to prevent overheating. | EN1 (enable input) | Automatically restarts once temperature returns to safe level. | | Inductor/Diode Short Protection | Detects a short-circuit across the boost inductor or output diode; if detected, controller shuts down to prevent catastrophic failure. | GATE , ISENSE , OVP | Detected by sensing abnormal voltage/current patterns. | mp3378e protection pin upd
: These pins monitor individual LED strings for open or shorted conditions. If a string is damaged, the controller can disable that specific channel or the entire driver to prevent thermal runaway. Disabled at startup if OVP voltage is < 75mV
| Symptom | Likely cause | Fix | |---------|--------------|-----| | Driver latches off permanently | PRO low + fault occurred | Cycle VCC or pull PRO high | | Driver keeps restarting every ~1s | PRO high + intermittent fault | Check LEDs, OVP resistor, or set PRO low | | Boost works only above 4.5V | UVLO enabled, no UPD | Enable UPD if low-VIN needed, else raise input | | No start-up at low VIN with UPD enabled | Input current limit tripped | Reduce load or add soft-start | | | Over-Current Protection (OCP) | Monitors inductor
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