Monolithic Power Systems Inc. MP3394SGF

Overview

MP3394SGF from Monolithic Power Systems is a step-up white LED driver IC with four independent current-regulated channels, designed for large LCD panel backlighting. It operates from 5V–28V input, delivers up to 200mA per string, achieves ±2.5% inter-string current matching, and supports programmable switching frequency (140–670 kHz) via external resistor. Used in flat-panel TVs and monitors where precise brightness uniformity and high-voltage boost capability are required.

For engineers reviewing the MP3394SGF datasheet, MP3394SGF pinout, MP3394SGF application, or MP3394SGF equivalent, key selection criteria include its 4-string current balance accuracy, TSSOP16EP thermal performance (θJA = 45°C/W), dual dimming modes (external PWM and DC-input burst PWM), open/short LED fault protection, and cascading capability for expanded channel count.

Technical Context

The MP3394SGF employs peak-current-mode control with fixed-frequency operation, using an external MOSFET for boost conversion and internal current sources for per-string regulation. Its COMP pin enables loop compensation, while ISET and BOSC pins set LED current and internal dimming frequency respectively.

It integrates under-voltage lockout (3.9V threshold), thermal shutdown (150°C), over-voltage protection (1.23V OVP trip), and robust fault handling-including marking-off of open or shorted strings after detection windows (e.g., 4096 switching cycles for short detection). The VCC LDO provides 5.8V for gate drive and internal logic.

Key Specifications

Pinout & Package

TSSOP16EP package with exposed thermal pad (must be connected to GND); 4.4mm × 5.0mm footprint, 0.65mm pitch, RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-string WLED driver applications.

Compared with MP3394SGF, the MP3394SGS trades thermal performance for ease of soldering and legacy footprint compatibility, while the MPQ3394BGLE-A adds automotive-grade robustness at higher cost and longer lead time-neither is pin-compatible without layout revision.

Availability

MP3394SGF is available at Aetrix Electronics and suitable for desktop LCD flat panels, industrial HMIs, broadcast video monitors, and commercial signage requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MP3394SGF 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 over 20 years of expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MP3394S product line targets large-format LCD backlighting, emphasizing high-current precision, multi-string scalability, and integrated protection-designed specifically for display manufacturers needing reliable, high-yield LED driver solutions.

FAQ

What is the maximum LED string voltage the MP3394SGF can support?

The MP3394SGF itself does not impose a fixed output voltage limit; instead, it regulates based on the highest forward voltage among the four strings. With proper external MOSFET and diode selection (e.g., 60V-rated components), output voltages up to 55V are achievable-verified in typical applications with 10-series WLED strings at 3.3V each (~33V total), plus headroom for regulation and ripple.

Can the MP3394SGF drive more than four LED strings?

Yes-two or more MP3394SGF ICs can be cascaded using shared VCC and COMP connections to drive 8, 12, or more strings from a single boost inductor. The master IC drives the MOSFET while slaves provide additional current sinks; this configuration maintains ±2.5% matching across all strings and is documented in the datasheet's "Expanding LED Channels" section.

How does the MP3394SGF handle an open LED string fault?

When an LED string opens, its corresponding LEDx pin voltage drops below 196mV. The IC detects this condition, marks that string as disabled, and continues regulating the remaining active strings. If all four strings open, the boost converter shuts down entirely. Recovery requires cycling EN or power reset-no automatic re-enabling occurs to prevent uncontrolled voltage rise.

What is the minimum recommended DBRT input voltage for dimming control?

The DBRT pin accepts a DC analog input from 0.2V to 1.2V for linear dimming control. Below 0.2V, the internal PWM duty cycle is clamped to 0%; above 1.2V, it saturates at 100%. This 1.0V range provides monotonic, predictable brightness scaling without requiring external DAC or PWM generator circuitry.

Does the MP3394SGF require an external Schottky diode in the boost path?

Yes-the MP3394SGF is a controller-only device and requires an external N-channel MOSFET and Schottky diode (e.g., B360) in the boost topology. The diode must handle peak output current and reverse voltage; typical selection is 40–60V rating with low forward voltage (<0.5V) to minimize conduction loss and improve efficiency.

Is the TSSOP16EP package lead-free and RoHS compliant?

Yes-the MP3394SGF uses a lead-free, RoHS-compliant TSSOP16EP package with matte tin plating. MPS confirms full compliance with Directive 2011/65/EU and provides material declarations and test reports upon request through their Quality Assurance portal.