Monolithic Power Systems Inc. EV3378E-F-00A

Overview

EV3378E-F-00A from Monolithic Power Systems is an evaluation board for the MP3378E 4-channel WLED controller with integrated high-efficiency buck converter, designed for LCD monitor backlighting. It supports 10 LEDs per string, 120mA per string, 8–24V input, and delivers 5V/2A from its buck stage - validated on desktop flat-panel display systems.

For engineers reviewing the EV3378E-F-00A datasheet, EV3378E-F-00A pinout, EV3378E-F-00A application, or EV3378E-F-00A equivalent, this board enables rapid validation of WLED current matching (±2.5%), dual dimming modes (PWM/analog), and integrated protection features including OCP, OTP, LED open/short detection, and buck thermal shutdown.

Technical Context

The EV3378E-F-00A implements the MP3378E IC in a TSSOP-28EP package, featuring two independent power stages: a boost-based 4-string WLED driver with external MOSFET control (M1 AM4490N) and a synchronous buck converter (L2=10μH, C21/C21A/C21B=22μF each) delivering regulated 5V output. Both sections share common ground planes but use separate GND1/GND2 nets for noise isolation.

Test conditions confirm operation at VIN = 16V, 10-series/4-parallel white LEDs, 120mA/string, and buck load up to 2A with <20mVpp ripple at full load. The board supports frequency synchronization (250kHz–2MHz), soft-start, and recoverable thermal shutdown - all accessible via dedicated EN1/EN2, SYNC, and BST pins.

Key Specifications

Availability

EV3378E-F-00A is available at Aetrix Electronics and suitable for LCD monitor development, flat-panel display qualification, and embedded backlight subsystem prototyping requiring stable component supply and traceable reference design validation.

Supply support for EV3378E-F-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, headquartered in Kirkland, WA, with global design and support operations.

The MP3378E product line targets cost-sensitive, high-reliability LCD backlight applications - integrating WLED driving and auxiliary power conversion into a single TSSOP-28EP IC to reduce board area and BOM count in monitor and TV designs.

FAQ

What is the maximum LED string voltage supported by the EV3378E-F-00A?

The board supports up to 24 V input and is configured for 10 white LEDs in series per string. Assuming 3.2 V forward voltage per LED, the total string voltage is ~32 V - achieved via the external boost stage (M1 AM4490N, D1 B160, L1 33 μH), with OVP threshold programmable via R10/R11.

Can the buck converter output voltage be adjusted?

Yes - the buck output is set to 5 V by default using R26 (51 kΩ), R27 (40.2 kΩ), and R28 (7.68 kΩ) in the FB divider network. Output voltage can be recalculated as VOUT = 0.8 V × (1 + R26/R27) and adjusted by changing these resistors per the MP3378E datasheet.

How is current matching accuracy verified on this board?

Current matching is measured at ±2.5% across all four strings under identical thermal and layout conditions, confirmed by oscilloscope waveforms (ILED traces) in the test report (page 5). Layout symmetry, matched sense resistors (R6), and Kelvin sensing minimize mismatch.

Does the board support synchronized switching between boost and buck stages?

No - the MP3378E does not synchronize the boost and buck switching frequencies. However, the buck section supports external clock sync (250 kHz–2 MHz) via the SYNC pin, while the boost operates at a fixed or programmable frequency independent of the buck stage.

What thermal management provisions are implemented?

The board uses exposed pad (EP) on U1 (MP3378E in TSSOP-28EP), thermal vias under M1 and L1, and copper pour on both layers. Thermal shutdown is recoverable and triggered at junction temperature >150°C, validated during 2A buck load and full-brightness LED tests.

Is the EV3378E-F-00A RoHS-compliant and lead-free?

Yes - all components on the board, including U1 (MP3378E), M1 (AM4490N), and passive parts, are RoHS-compliant and lead-free per MPS green status documentation and BOM manufacturer part numbers (e.g., Yageo RC0603FR-07xxxL, muRata GRM series).