Monolithic Power Systems Inc. EV3391EF-00A

Overview

EV3391EF-00A from Monolithic Power Systems is an evaluation board for the MP3391EF step-up white LED driver IC, designed to validate 8-string parallel WLED backlighting for large LCD panels. It supports 10–28 V input, drives up to 12 LEDs per string at 60 mA/string, achieves ≤2.5% inter-string current regulation, and integrates external MOSFET control with programmable OVP and thermal shutdown.

For engineers reviewing the EV3391EF-00A datasheet, EV3391EF-00A pinout, EV3391EF-00A application, or EV3391EF-00A equivalent, this board enables rapid validation of MP3391EF-based backlight systems in notebook PCs, LCD monitors, and automotive displays - focusing on efficiency, dimming fidelity, and fault protection behavior under real load conditions.

Technical Context

The EV3391EF-00A implements a fixed-frequency current-mode boost converter architecture using the MP3391EF IC, which controls two external MOSFETs (N-channel AG9977GH and P-channel AM4499P) and regulates eight independent LED strings via dedicated ISENSE and SSET terminals. Each string includes discrete 10 Ω ballast resistors for precision current matching.

It supports both DC and PWM dimming modes: PWM dimming is applied via the DBRT pin with 100 Hz–2 kHz frequency range and ≥1.2 V amplitude, while switching frequency is set by resistor R1 (357 kΩ) to 1.1 MHz. Protection features include open/short LED detection, overvoltage clamping at 6.3 V, and thermal shutdown triggered at internal junction temperature.

Key Specifications

Availability

EV3391EF-00A is available at Aetrix Electronics and suitable for notebook PC backlight validation, LCD monitor reference design development, and automotive display qualification requiring stable component supply and documented evaluation hardware.

Supply support for EV3391EF-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 MP3391EF product line targets high-efficiency, multi-string LED backlighting for large-format displays, emphasizing tight current matching, flexible dimming, and robust fault protection in space-constrained designs.

FAQ

What is the maximum number of LED strings supported by the EV3391EF-00A?

The board is configured for 8 parallel white LED strings, each with 12 series-connected LEDs. It can be extended to 16 strings by populating zero-ohm resistors R32, R33, and R36 to enable dual-MP3391EF parallel operation as documented in the Quick Start Guide.

Does the EV3391EF-00A support analog dimming?

No - the board supports only PWM and DC-level dimming via the DBRT pin. Analog dimming is not implemented; current regulation is fixed per string by the 10 Ω ballast resistors and MP3391EF's internal current-sense architecture.

What protection features are active and verified on this evaluation board?

All MP3391EF-integrated protections are functional: open/short LED detection (via OVP and ISENSE monitoring), overvoltage protection (clamped at 6.3 V), thermal shutdown (triggered internally), and under-voltage lockout (10 V start-up threshold). These are validated in the schematic and bill of materials.

Can the EV3391EF-00A drive different LED forward voltages per string?

Yes - the MP3391EF uses individual current-sense paths per string and a common boost output, allowing mismatched V_F across strings (e.g., due to binning or aging) while maintaining ≤2.5% current regulation accuracy through its internal ballast circuitry.

Is the board RoHS-compliant and lead-free?

Yes - all components on the EV3391EF-00A, including the MP3391EF IC and passive elements, are lead-free and comply with the RoHS directive, as confirmed in the official MPS documentation and BOM.

What external components must be added to use the board with a custom LED load?

No additions are required for standard use: connect 12-series white LEDs to LED+ and LED1–LED8 pins. Ensure total string V_F remains within the MP3391EF's 6.3 V OVP limit and that input voltage stays within 10–28 V. No external compensation or feedback network is needed - all are pre-configured.