Monolithic Power Systems Inc. EV3399EF-00A

Overview

EV3399EF-00A from Monolithic Power Systems is a 24-string white LED driver evaluation board built around two parallel MP3399EF ICs, supporting 12 LEDs per string at up to 60mA/string, with 2.5% inter-string current regulation accuracy, 8–28V input range, and programmable over-voltage protection for LCD backlighting applications.

For engineers reviewing the EV3399EF-00A datasheet, EV3399EF-00A pinout, EV3399EF-00A application, or EV3399EF-00A equivalent, this board enables rapid validation of high-efficiency boost-based LED driving for large-panel displays, including PWM dimming implementation, fault protection behavior, and thermal performance under real load conditions.

Technical Context

The EV3399EF-00A implements a fixed-frequency, current-mode boost architecture using external power MOSFETs (P-channel M1 and N-channel M2) and internal string current ballast. Each MP3399EF drives 12 LED strings, enabling 24 total strings in parallel with independent current sensing via 0.05Ω sense resistors (R24).

Board-level protections include under-voltage lockout (UVLO), open/short LED detection, over-voltage clamping, and thermal shutdown-mirroring the MP3399EF's integrated safety features. The 33µH boost inductor (L1) and 1µF/100V ceramic output capacitors (C13, C16) support stable high-current operation up to 90% efficiency.

Key Specifications

Availability

EV3399EF-00A is available at Aetrix Electronics and suitable for LCD TV backlight development, notebook PC display validation, and industrial monitor design requiring stable component supply and proven reference implementation.

Supply support for EV3399EF-00A 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 core expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MP3399EF product line targets large-format LCD backlighting, delivering high-efficiency, multi-string current regulation with robust fault protection for consumer and industrial displays.

FAQ

What is the maximum total LED forward voltage supported by the EV3399EF-00A?

The board supports up to 12 white LEDs per string, each with typical V_F ≈ 3.2V, yielding ~38.4V max per string. With external MOSFETs and proper layout, the boost stage reliably delivers ≥40V output under full load and thermal limits.

How is open-LED fault detection implemented on this evaluation board?

Each LED string connects to dedicated current-sense nodes monitored by the MP3399EF's internal comparators. An open condition triggers immediate shutdown of the affected channel and asserts FAULT signal, visible at U1/U2 pin 25, with recovery requiring EN pin toggle.

Can the EV3399EF-00A drive mixed-color LED strings (e.g., RGB)?

No-the board and MP3399EF are optimized for white LED strings with matched V_F. RGB strings exhibit significantly different forward voltages and dynamic characteristics, requiring separate current control and timing not supported by this fixed-architecture design.

What is the role of the 0.05Ω resistor (R24) on the board?

R24 serves as the main current-sense element for the global feedback loop. Its 0.05Ω value sets the peak inductor current limit and scales the per-string current reference, directly determining the 60mA maximum per string when used with MP3399EF's internal gain.

Does the board support analog dimming in addition to PWM?

No-EV3399EF-00A implements only PWM dimming via the DBRT pin. The MP3399EF does not include an analog dimming interface; brightness control relies exclusively on duty-cycle modulation of the applied PWM signal.

Is thermal shutdown active during normal operation at full load?

Thermal shutdown activates only if board temperature exceeds ~150°C at the MP3399EF die. Under continuous 60mA/string operation with adequate airflow, junction temperatures remain below 110°C, well within safe operating limits.

How are the two MP3399EF ICs synchronized on this board?

The ICs share the same RT resistor (R51) and clock signal path, ensuring phase-aligned switching. No external synchronization pins are used; fixed-frequency operation with matched components achieves <5° phase skew between channels.