Monolithic Power Systems Inc. EV3391EY-00A

Overview

EV3391EY-00A from Monolithic Power Systems is an evaluation board for the MP3391EY 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 EV3391EY-00A datasheet, EV3391EY-00A pinout, EV3391EY-00A application, or EV3391EY-00A equivalent, this board enables rapid validation of MP3391EY-based backlight systems in notebook PCs, LCD monitors, and automotive displays - focusing on efficiency, string matching, dimming interface, and fault protection behavior.

Technical Context

The EV3391EY-00A implements a fixed-frequency current-mode boost converter architecture using the MP3391EY IC, which controls two external MOSFETs (N-channel AG9977GH and P-channel AM4499P) and delivers regulated current to eight independent LED strings. Each string includes dedicated current-sense resistors (0.1 Ω) and ballast circuitry enabling 2.5% current matching across strings.

It supports dual dimming modes: DC-burst PWM via DBRT pin (100 Hz–2 kHz, ≥1.2 V amplitude) and analog dimming via ISET pin; OVP threshold is factory-set to 6.3 V, and thermal shutdown activates at ~150 °C. The board's layout accommodates parallel operation of two MP3391EY ICs for 16-string expansion via jumper R32/R33/R36.

Key Specifications

Availability

EV3391EY-00A is available at Aetrix Electronics and suitable for LCD monitor backlight validation, notebook PC design verification, and automotive display prototyping requiring stable component supply and documented reference performance.

Supply support for EV3391EY-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 emphasis on efficiency, integration, and reliability for power management and LED lighting applications.

The MP3391 product line targets large-panel LCD backlight drivers requiring precise multi-string current regulation, flexible dimming, and robust fault protection - optimized for cost-sensitive, high-volume display systems.

FAQ

What input voltage range does the EV3391EY-00A support?

The board accepts 10 V to 28 V DC input, aligned with the MP3391EY IC's operational specification. This range supports common 12 V and 24 V display power supplies and allows margin for line transients and ripple without triggering under-voltage lockout.

How is LED string current set and verified on this board?

Each string uses a 0.1 Ω, 1% tolerance current-sense resistor (R10/R11), producing 6 mV drop at 60 mA. The MP3391EY regulates current by comparing this voltage to its internal 60 mV reference, achieving ≤2.5% matching across all eight strings as confirmed in the schematic and BOM.

Can the EV3391EY-00A drive more than 8 LED strings?

Yes - the board supports 16-string operation by populating 0 Ω resistors at R32, R33, and R36 to enable master-slave parallel configuration of two MP3391EY ICs (U1 and U2), as detailed in the Quick Start Guide and schematic page 3.

What dimming methods are supported and how are they implemented?

The board supports PWM dimming via the DBRT pin (100 Hz–2 kHz, ≥1.2 V amplitude) and analog dimming via the ISET pin. PWM mode uses external timing components (R31/C14) to configure burst frequency, while analog dimming adjusts output current proportionally to ISET voltage (0–1.2 V).

Does the board include protection against LED open/short faults?

Yes - the MP3391EY IC provides open-LED detection (via OVP pin monitoring), short-LED protection (via ISENSE pin current limiting), and thermal shutdown (~150 °C). These functions are fully implemented on the EV3391EY-00A with no additional external circuitry required.

Is the EV3391EY-00A RoHS-compliant and lead-free?

Yes - all components on the board, including the MP3391EY IC, are lead-free and comply with the RoHS directive, as stated in the official documentation and confirmed by MPS's green status program on their website.