Mp3378e Protection Pin Upd Instant

This article provides a detailed look at the MP3378E's protection features and their practical implications, tailored for hardware engineers and repair technicians.

: Detects severe faults in the power path (e.g., a shorted boost diode) and immediately halts operation.

The MP3378E features a sophisticated protection architecture designed for high-reliability monitor applications. Unlike simpler drivers, it provides independent protection for both the WLED step-up controller and the buck converter. 1. Programmable Over-Voltage Protection (OVP)

+-----------------------+ | MP3378E | | TSSOP-28 | | | ------> OVP (Over-Voltage) | ------> COMP (Compensation) | ------> ISET (Current Set) | ------> EN1 (WLED Enable) | ------> EN2 (Buck Enable) | | | +-----------------------+ OVP (Over-Voltage Protection) Pin mp3378e protection pin upd

: By placing a temporary parallel resistor over the lower leg of the OVP voltage divider, the voltage sensed by Pin 9 is kept safely below the trigger threshold.

To set the maximum allowable output voltage, select the upper ($R_OVP_UP$) and lower ($R_OVP_LOW$) divider resistors using the formula: $$V_OUT_MAX = V_OVP_TH \times \left(1 + \fracR_OVP_UPR_OVP_LOW\right)$$

To help narrow this down, feel free to share when it turns on, or if the buck converter side is still outputting power after the backlight cuts off. Share public link This article provides a detailed look at the

The MP3378E relies on to ensure the open-circuit boost voltage does not destroy the external N-channel MOSFET, filtering capacitors, or output diodes. How OVP Works Internally

If a string opens, the corresponding VLED pin drops down to near 0V. The chip attempts to drive more current, detects the fault, and shuts off that specific channel.

The controller manages four independent channels with 2.5% current matching accuracy. To set the maximum allowable output voltage, select

The integrated buck converter includes its own Over-Current Protection (OCP) with Hiccup Mode . In a short-circuit event on the buck output, it will periodically attempt to restart, significantly reducing power dissipation during the fault. Technical Summary Table Protection Mechanism Pin Involvement Backlight Safety Over-Voltage (OVP) OVP Pin (via resistor divider) String Integrity Open/Short LED Protection LED1 - LED4 Pins System Power Buck Over-Current (OCP) Internal Sensing (Hiccup Mode) Thermal Safety Recoverable Shutdown Internal Die Temperature Sensor MP3378E - Monolithic Power Systems

Disconnect the LED+ and LED- cables from the driver board. Replace with a dummy load (e.g., 1kΩ resistor from SW to GND and a 47kΩ from VOUT to GND). This removes actual LEDs from the equation.