Monolithic Power Systems Inc. MP3383GF-Z

Overview

MP3383GF-Z from Monolithic Power Systems is a 4-string step-up WLED controller IC designed for large-panel LCD backlighting, supporting up to 400mA per string, 80V absolute maximum string voltage, and 6V–33V input range. It drives an external N-channel MOSFET, employs peak current control with configurable 450–550kHz switching frequency, and delivers 1.8% inter-string current matching for uniform brightness in desktop monitors and all-in-one PCs.

For engineers reviewing the MP3383GF-Z datasheet, MP3383GF-Z pinout, MP3383GF-Z application, or MP3383GF-Z equivalent, key selection factors include its TSSOP-16EP package thermal performance (θJA = 45°C/W), dual dimming support (PWM and analog via ADIM), cascading capability for multi-IC LED arrays, and integrated protections including OVP, OTP, LED open/short detection, and cycle-by-cycle current limiting.

Technical Context

The MP3383GF-Z implements fixed-frequency peak current-mode control with an external oscillator resistor (ROSC) setting fSW between 450–550kHz at 100kΩ. Its internal 12V LDO (VCC) powers the gate driver when VIN >13V and features 500mV UVLO hysteresis for stable startup.

Four independent current sources regulate LED strings with 1.8% matching accuracy at 90mA and 250mV regulation voltage at 100mA, minimizing power loss. Protection logic includes OVP threshold set via resistor divider on OVP pin, latch-off ISENSE limit at 500mV, and short-string detection triggered after 16–128 cycles depending on configuration.

Key Specifications

Pinout & Package

TSSOP-16EP package with exposed pad thermally connected to GND; 16-pin layout optimized for LED string routing and thermal dissipation in high-current backlight applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar WLED controller applications.

Compared with RT8532GQW and LM3409QMYX/NOPB, the MP3383GF-Z uniquely integrates four matched current sinks, cascading capability, and dual dimming-making it optimal for high-reliability, space-constrained large-panel backlight systems where channel count, uniformity, and thermal density are primary constraints.

Availability

MP3383GF-Z is available at Aetrix Electronics and suitable for desktop LCD flat-panel displays, all-in-one PCs, and 2D/3D LCD TVs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP3383GF-Z 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 power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP3383 product line targets large-format LCD backlighting applications, delivering integrated step-up control, multi-string current regulation, and robust fault protection in compact packages for consumer and commercial displays.

FAQ

What is the maximum allowable LED string voltage for MP3383GF-Z?

The MP3383GF-Z has an absolute maximum rating of +80V on each LEDx pin (LED1–LED4). This allows driving up to 22 white LEDs in series assuming typical forward voltage of 3.6V per LED, with 10–15% margin for temperature drift and ripple. Operation above 80V risks permanent damage to internal current sources.

How does the MP3383GF-Z handle an open LED string during operation?

When one string opens, the corresponding LEDx pin voltage drops below 100mV, triggering open-string protection. The IC marks that string as disabled, continues boosting VOUT until the OVP threshold is reached, then regulates output based on the remaining active strings' voltage requirements-ensuring uninterrupted illumination of functional strings.

Can MP3383GF-Z be used with input voltages below 6V?

No. The MP3383GF-Z specifies a minimum operating input voltage of 6V in its Recommended Operating Conditions. Below this, the internal 12V LDO cannot regulate properly, gate drive strength degrades, and current regulation accuracy falls outside guaranteed specifications-even if the chip appears to function intermittently.

What is the purpose of the exposed pad on the TSSOP-16EP package?

The exposed pad on the MP3383GF-Z's TSSOP-16EP package must be soldered to a GND plane on the PCB. It serves as the primary thermal path, reducing θJA from 80°C/W (SOIC-16) to 45°C/W and enabling 2.78W continuous power dissipation at 25°C ambient-critical for sustained 400mA/string operation without thermal derating.

Does MP3383GF-Z support I²C or SPI communication for configuration?

No. The MP3383GF-Z is a hardware-configured analog controller with no digital interface. All settings-including switching frequency, OVP threshold, LED current, and dimming behavior-are established via external resistors and PWM signals on dedicated pins (OSC, OVP, ISET, ADIM, PWM).

How is thermal shutdown recovery handled in MP3383GF-Z?

Upon reaching 150°C junction temperature, the MP3383GF-Z shuts down completely. Recovery occurs automatically when the die cools to approximately 125°C (25°C hysteresis), at which point the IC restarts with internal soft-start-no external reset signal or power cycle is required, ensuring graceful fault recovery in thermally constrained enclosures.

What is the minimum recommended PWM dimming frequency for the ADIM pin?

The ADIM pin includes an internal 10MΩ/100pF RC filter, resulting in a 159Hz cutoff frequency. To ensure effective filtering and avoid visible ripple in LED output, MPS recommends applying PWM signals ≥20kHz-this yields >126dB attenuation of fundamental frequency, keeping dimming-induced brightness variation below 0.1%.