Monolithic Power Systems Inc. EV3378-S-00A

Overview

EV3378-S-00A from Monolithic Power Systems is a dual-function evaluation board integrating the MP3378 IC - a 4-string WLED boost controller (120 mA/string, 2.5% current matching) and a synchronous buck converter (2 A, 0.8–5 V output, 90 mΩ/40 mΩ internal MOSFETs) - designed for LCD monitor backlight and auxiliary bus power. It supports independent analog/PWM dimming, LED open/short protection, and OCP/OTP/UVP/OVP.

For engineers reviewing the EV3378-S-00A datasheet, EV3378-S-00A pinout, EV3378-S-00A application, or EV3378-S-00A equivalent, this board enables rapid validation of MP3378-based WLED driver + buck supply designs under 8–24 V input, 10-LED-per-string configurations, and real-world thermal/load transient conditions.

Technical Context

The EV3378-S-00A implements the MP3378's dual-regulator architecture: the boost section uses external MOSFET (AM4490N), diode (B160), and inductor (33 µH) to drive four parallel LED strings with per-string current regulation via ISET resistors; the buck section integrates power switches and operates at fixed 235 kHz with AAM mode for light-load efficiency.

Board-level features include synchronized PWM/analog dimming control (PWM, A-DIM, EN/BL pins), OVP threshold set by R10/R11, soft-start via C9/C10, and comprehensive fault reporting through VSENSE, OVP, and thermal shutdown circuits - all validated per MPS Rev. 1.1 test conditions (VIN = 16 V, 10 LEDs/string, TA = 25 °C).

Key Specifications

Availability

EV3378-S-00A is available at Aetrix Electronics and suitable for LCD monitor backlight development, embedded display power subsystem validation, and dual-rail (WLED + logic bus) supply qualification requiring stable component supply and traceable reference design implementation.

Supply support for EV3378-S-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 EV3378-S-00A belongs to MPS's evaluation board product line, engineered specifically to accelerate design-in of the MP3378 WLED + buck controller for LCD monitor and commercial display applications requiring integrated backlight and system rail power.

FAQ

What is the primary function of the EV3378-S-00A evaluation board?

The EV3378-S-00A is a fully assembled reference design board for the MP3378 IC, enabling immediate hardware validation of its dual functionality: driving four independent white LED strings with precise current regulation while simultaneously generating a regulated 0.8–5 V, 2 A output for system bus or standby power in LCD monitors.

Which IC does the EV3378-S-00A evaluate, and what package does it use?

The board evaluates the MP3378GY IC, a monolithic analog power controller housed in an SOIC-28 package. This IC integrates both the 4-string WLED boost controller and the synchronous buck converter on a single die, with dedicated pins for LED string outputs, buck switching (SW), gate drive (GATE), feedback (FB), and dimming inputs (PWM, A-DIM).

How do I configure analog vs. PWM dimming on this board?

Analog dimming is enabled by applying 0.4–1.5 V DC to the A-DIM pin (R21 sets bias); PWM dimming requires a 200 Hz–2 kHz square wave (0.4 V low / >1.5 V high) on the PWM pin. Both modes operate independently - simultaneous use is not supported. The board includes pull-up resistors (R20, R21) and RC filters (C9, C10) to stabilize dimming signals.

What protections are implemented and how are they verified?

The board demonstrates MP3378's full protection suite: LED open/short (via ISENSE monitoring), OVP (set by R10/R11 divider), OCP (internal current limit), OTP (thermal shutdown), and inductor/diode short detection. These are validated in the test report (Rev. 1.1) using forced fault waveforms - e.g., shorting one LED string triggers immediate current shutoff without latch-up.

Can the buck output voltage be adjusted, and what components set it?

Yes - the buck output is adjustable from 0.8 V to 5 V using the FB resistor divider. On this board, R26 (51 kΩ), R27 (40.2 kΩ), and R28 (7.68 kΩ) form a three-resistor network that sets VOUT ≈ 5 V. Replacing R27 and R28 with standard E96 values allows precise tuning; the FB pin references 0.8 V internally, and regulation accuracy is ±1.5% over line/load/temperature.

Is the EV3378-S-00A RoHS-compliant and lead-free?

Yes - all components on the EV3378-S-00A board comply with RoHS Directive 2011/65/EU and are lead-free and halogen-free, consistent with MPS's green policy. The MP3378GY IC itself is qualified to JEDEC J-STD-020 moisture sensitivity level 3, and board-level soldering uses lead-free reflow profiles per IPC-J-STD-001.