Achieving reliable protection requires careful PCB layout. MPS provides specific guidelines for both the WLED controller and buck converter.
The OVP pin updates the chip's internal logic regarding output voltage health. Technicians connect an external resistor divider from the high-voltage rail back to the OVP pin.
When anomalous conditions occur, the internal logic updates the protection latch status, deciding whether to invoke , force a temporary thermal shutdown, or isolate specific damaged LED strings. Protection Metric Monitored Via Pinout System Response Over-Voltage Protection (OVP) mp3378e protection pin upd
Before modifying any pins, it is crucial to understand the baseline capabilities of the integrated circuit (IC) as outlined in the Mouser Electronics MP3378E Datasheet : Specifications 4 independent strings Max String Current 350mA per channel Input Voltage Range Dimming Modes Independent PWM and Analog Integrated Protections OCP, OTP, UVP, OVP, LED Short/Open Package Type TSSOP-28 EP Anatomy of the MP3378E Protection Pins
In many repair scenarios, the serves as the primary "protection pin" that triggers a shutdown. Achieving reliable protection requires careful PCB layout
A common field issue occurs when the . During start-up, the boost output rises. If the OVP divider reaches 2.0V before the PROT pin finishes its soft-start ramp (0→0.8V), the IC will falsely trigger OVP and shut down.
For robust LED backlight designs, always treat the UPD pin not as an afterthought, but as a primary safeguard that can protect both the driver and the end application. Technicians connect an external resistor divider from the
: A high-efficiency step-down component providing internal bus voltage and standby power.