Monolithic Power Systems Inc. MP3378EGF-P

Overview

MP3378EGF-P from Monolithic Power Systems is a dual-function integrated WLED backlight controller and buck DC-DC converter in a single TSSOP-28 EP package. It delivers four independent 350mA LED current channels with 2.5% matching accuracy, supports analog/PWM dimming, and integrates a synchronous buck regulator with 144mΩ/80mΩ internal MOSFETs for auxiliary bus voltage generation - deployed in desktop LCD monitors and flat-panel displays requiring precise, high-efficiency backlight power management.

For engineers reviewing the MP3378EGF-P datasheet, MP3378EGF-P pinout, MP3378EGF-P application, or MP3378EGF-P equivalent, this device serves as a complete backlight + auxiliary supply solution where tight LED current matching, OVP/OTP/short-string protection, and synchronized buck operation are critical selection criteria.

Technical Context

The MP3378EGF-P integrates two independent control loops: a peak-current-mode boost controller for WLED strings (programmable 150–590kHz via OSC resistor) and a fixed-frequency (235kHz typ.) current-mode buck converter with frequency sync capability (250kHz–2MHz). Both sections feature dedicated enable pins (EN1/EN2), separate ground domains (GND1/GND2), and isolated feedback paths (COMP for boost, FB for buck).

It implements dual protection architectures: the WLED section includes per-string open/short detection (via LED1–LED4 pins), recoverable thermal shutdown (150°C trip, 25°C hysteresis), and ISENSE-based cycle-by-cycle current limiting; the buck section provides hiccup-mode OCP, UVLO (3.9V rising), and thermal shutdown (150°C, 20°C hysteresis) with internal soft-start (1.5ms typical).

Key Specifications

Pinout & Package

TSSOP-28 EP package with exposed thermal pad (must be connected to GND); 0.65mm pitch; RoHS-compliant, halogen-free construction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-rail backlight + auxiliary supply applications.

Compared with RT8532GQW and LM3409QMY/NOPB, the MP3378EGF-P uniquely combines 4-string precision current regulation, per-string fault diagnostics, and a fully integrated synchronous buck - reducing total solution size by ~40% and eliminating inter-IC timing coordination overhead.

Availability

MP3378EGF-P is available at Aetrix Electronics and suitable for desktop LCD monitors, flat-panel video displays, and industrial HMI panels requiring stable component supply, long-term lifecycle support, and guaranteed RoHS/halogen-free compliance.

Supply support for MP3378EGF-P includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with design centers in the US, China, and Taiwan.

The MP3378E product line targets cost-sensitive, space-constrained LCD backlight systems - integrating WLED control and auxiliary power conversion to eliminate discrete solutions in monitor, TV, and industrial display applications.

FAQ

What is the maximum input voltage supported by the MP3378EGF-P's WLED controller section?

The WLED controller (VIN1) supports up to +28V absolute maximum, with recommended operating range of 5V to 24V. This allows direct connection to 12V or 24V industrial or consumer power rails without pre-regulation - verified in Absolute Maximum Ratings and Recommended Operating Conditions tables.

Can the MP3378EGF-P drive LED strings with different forward voltages simultaneously?

Yes - the boost converter automatically regulates to the highest active LED string voltage (via LED1–LED4 sensing), ensuring all strings receive sufficient headroom. Open-string protection disables faulty strings while maintaining regulation on remaining ones, as confirmed in the Operation section and OVP/LEDX fault logic description.

How does the buck converter's frequency synchronization work with an external clock?

The SYNC pin accepts an external clock (250kHz–2MHz) whose falling edge aligns the internal buck oscillator's rising edge. Logic thresholds are 1.8V (high) and 0.6V (low); the external clock must exceed the internal 235kHz frequency to avoid instability - detailed in Buck Converter Section and PIN FUNCTIONS table.

Is the ADIM pin compatible with both DC and PWM signals?

Yes - ADIM accepts either a DC voltage (0.41–1.49V for linear dimming) or a >20kHz PWM signal. An internal 10MΩ/100pF RC filter converts PWM to a smoothed DC level; this dual-mode capability is explicitly specified in the PIN FUNCTIONS and OPERATION sections.

What thermal protection mechanisms are implemented in the MP3378EGF-P?

Two independent thermal shutdown circuits exist: WLED section trips at 150°C (25°C hysteresis), buck section at 150°C (20°C hysteresis). Both are recoverable - operation resumes once die temperature falls below respective lower thresholds - confirmed in Protection subsections and Electrical Characteristics tables.

Does the MP3378EGF-P require external compensation components for stability?

Yes - COMP (boost error amplifier output) requires an external RC network (resistor + capacitor in series to GND) for loop compensation, as stated in PIN FUNCTIONS and BLOCK DIAGRAM. The buck section uses internal compensation, but boost loop stability depends on user-selected external components per application conditions.