Pin Upd [2021] — Mp3378e Protection

The MP3378E does not have a single pin labeled specifically as "protection"; instead, its comprehensive protection suite is spread across several specialized pins including OVP, ISET, ISENSE, and LED1–4.

Mastering the MP3378E Protection: A Deep Dive into Backlight Controller Faults Monolithic Power Systems (MPS) MP3378E mp3378e protection pin upd

Monitors and limits current to prevent damage from short circuits. LED Open and Short Protection: The MP3378E does not have a single pin

This content is written for hardware engineers and power supply designers. A 50ms delay before enabling the MP3378E after

VLEDX_OVcap V sub cap L cap E cap D cap X _ cap O cap V end-sub Latch-off Current Limit VLMTcap V sub cap L cap M cap T end-sub Thermal Shutdown TSTcap T sub cap S cap T end-sub Design Updates and Best Practices (The "UPD")

• A 50ms delay before enabling the MP3378E after VIN stabilization.
• A soft-start ramp for PWM dimming from 10% to 100% over 100ms to avoid transient UPD.

• At high temperature, NTC resistance drops → UPD voltage falls below 1.22V → IC latches off.

• ENABLE / EN pin: some devices disable switching via EN when a fault occurs; PROT may assert EN or vice versa.
• FAULT or PG (power-good) pins: PROT may work alongside a PG pin that reports regulator output margin; combined signals help system power sequencing.
• Soft-start capacitor: a latched protection may require discharge of the soft-start capacitor before a restart; an auto-retry/hiccup mode may preserve soft-start behavior on each retry.
• Current-sense amplifier or RSENSE resistor: OCP threshold depends on the sensed voltage across a resistor or the integrated current-sense path; PROT logic reads this measurement.

Overview of the MP3378E