Mp3378e Protection Pin Upd | Pro ✓ |
Measure the voltage on pins 5, 6, 7, and 8. They should ideally be similar. A significantly higher or lower voltage than others indicates a faulty LED string. 4. Troubleshooting "Protection Pin UPD" (UVP/OVP/LED Short)
[ t_SS (ms) = \fracC_PROT (nF) \times 0.8V5\mu A ]
Current sinks for the 4 LED strings; failures here often trigger protection.
: If an LED string becomes disconnected (open circuit), the boost converter continuously attempts to raise the voltage to satisfy the missing feedback loop.
The most stable way to bypass false-positive protection triggers without damaging the IC is to artificially clamp the OVP pin feedback loop. MP3378E - Monolithic Power Systems mp3378e protection pin upd
conditions across its four channels to prevent uneven brightness or circuit damage. WLED Controller Safety : Features Over-Current Protection (OCP) Over-Temperature Protection (OTP) Under-Voltage Protection (UVP) Over-Voltage Protection (OVP) Component Monitoring : Specifically includes inductor and diode short protection
To ensure the chip runs safely, several hardware pins must be correctly biased with discrete passive components. If these pins read out-of-specification values during startup, the IC will refuse to drive the external switching MOSFET. 1. The Over-Voltage Protection (OVP) Pin
Are you currently troubleshooting a issue or designing a new PCB layout for this chip? MP3378E - Monolithic Power Systems
: It is typically connected to a resistor divider from the output voltage. Measure the voltage on pins 5, 6, 7, and 8
that combines a 4-channel WLED controller with a high-efficiency buck converter, primarily used in monitor applications. MPS | Monolithic Power Systems
The requires a 10kΩ resistor connected to ground to properly update, manage, and engage its multi-layer safety suite . Manufactured by Monolithic Power Systems (MPS) , the MP3378E is a highly efficient, single-chip combination integrated circuit (IC) featuring a 4-channel WLED backlight controller and a high-efficiency synchronous buck converter designed for flat-panel LCD displays and TV monitors.
Limits current to the external MOSFET and internal buck converter.
When troubleshooting backlights managed by MPS controllers , technicians modify the feedback pins to stop the IC from shutting down. This allows them to measure the operating currents across all four channels and find the fault. The most stable way to bypass false-positive protection
| Component | Value | Function | | :--- | :--- | :--- | | (pin 20) | 22nF – 47nF | Start-up delay / filter | | R_TOP (OVP) | 200kΩ – 1MΩ | Sets VOUT OVP | | R_BOTTOM (OVP) | 10kΩ – 47kΩ | Ground reference | | R_PROT (series) | 1kΩ – 10kΩ | Optional: limits current to pin |
If you need help resolving a specific hardware fault with this IC, pleaseg., repeating blinks, no power, clicking sounds)
If the internal OVP of the MP3378E (e.g., 80V) is too high for your LEDs, use a resistor divider from the boost output to UPD via a Zener diode.
: An internal thermal sensor triggers a shutdown if the junction temperature exceeds safe limits (
Select feedback resistors that trip the OVP pin just above the maximum required LED string voltage drop to prevent over-boosting during open-circuit faults.
