This pin samples the boosted output voltage via a resistive voltage divider network. If the feedback voltage surpasses the internal reference threshold (typically due to an open LED string where the boost converter aggressively overcompensates), the IC immediately latches off the gate driver channel to prevent component explosion. 2. The LED1 to LED4 Channels
Therefore, there is no direct "UPD" pin to configure. The intended reference is almost certainly to the device’s built-in UVP or other protection mechanisms.
Once diagnostics point to the underlying issue, use the following steps to ensure a long-lasting repair:
Open-string protection is achieved by monitoring the voltage on the OVP pin. If an LED string fails, the controller may boost output voltage excessively; if it hits the programmed OVP threshold, the chip shuts down to prevent damage. mp3378e protection pin upd
When a television or monitor turns on, displays an image for 1 to 5 seconds, and then goes dark while audio or flashlight-visible graphics remain, the MP3378E has entered protection mode. This typical failure loop occurs for three main reasons:
If the junction temperature exceeds the safety limit (calculated by
: A resistor divider samples the output voltage. If an LED string goes open-circuit, the boost voltage spikes. Once the voltage at the OVP pin exceeds its preset internal threshold (typically around 1.2V to 2.0V depending on configuration), the IC shuts down the gate drive to prevent the filter capacitors and MOSFET from exploding. 2. The COMP (Compensation / Fault Feedback) Pin This pin samples the boosted output voltage via
RDS(ON)cap R sub cap D cap S open paren cap O cap N close paren end-sub
is triggered when the MP3378E detects a potential fault condition (e.g., rising output voltage or current mismatch) but the expected protection response (e.g., PWM dimming cycle termination or soft-start reset) does not occur within a predefined timing window. In essence, UPD indicates that the protection pin is receiving a fault signal under the threshold for normal shutdown, creating an ambiguous logic condition.
For detailed design-in support, refer to the official MP3378E datasheet and EV3378E-F-00A evaluation board documentation available from MPS. The LED1 to LED4 Channels Therefore, there is
The MP3378E operates as a multi-stage power manager in a compact . Understanding its two primary internal systems explains why the protection modes trigger: The WLED Controller
does not provide a standard "bypass" for safety reasons, common industry practices for similar ICs often involve manipulating feedback or protection pins (like OVP) with resistors or LEDs to prevent the IC from entering a latch-off state during testing. MP3378E - Monolithic Power Systems
A working channel will have a low voltage (roughly 0.5V–1V). A channel with an open string will show close to the Boost voltage, while a shorted channel will show near 0V. 2. Monitor the OVP Pin
By updating the protection pin to handle faults with intelligence—latching only when necessary, filtering noise, and isolating failures—MP3378E transforms the driver from a fragile component into a resilient node. The protection pin is no longer just an input; it is the conscience of the circuit. It weighs the cost of a voltage spike against the cost of a system crash.