Monolithic Power Systems Inc. EV4425M-QB-00A

Overview

EV4425M-QB-00A from Monolithic Power Systems is a fully assembled and tested evaluation board for the MPQ4425MGQB synchronous step-down LED driver IC, supporting 1.5A continuous LED current across a 4V–36V input range at 2.2MHz switching frequency. It integrates EMI filters, PWM dimming interface (100Hz–2kHz), fault indication (LED short/open/thermal shutdown), and operates in forced CCM mode with 0.2V reference voltage.

For engineers reviewing the EV4425M-QB-00A datasheet, EV4425M-QB-00A pinout, EV4425M-QB-00A application, or EV4425M-QB-00A equivalent, this board enables rapid validation of automotive-grade LED driver performance-including CISPR25 Class 5 radiated/conducted emissions compliance, efficiency under load, and thermal behavior-with pre-populated QFN-13 MPQ4425MGQB, dual 2.2µH power inductors, and full input/output filtering.

Technical Context

The EV4425M-QB-00A implements the MPQ4425MGQB's internal 85mΩ high-side and 50mΩ low-side MOSFETs in a fixed-frequency (2.2MHz) synchronous buck topology optimized for white LED biasing. It uses valley-current-mode control with proprietary switching-loss-reduction technology and supports both enable logic (1.45V turn-on threshold) and external PWM dimming via the EN/DIM pin.

Board-level design includes input EMI filtering (BLM41PG181SN1L bead + ceramic caps), output current sensing via parallel 400mΩ resistors (R5/R6/R7), feedback loop compensation (RT network), and fault reporting through an open-drain /FAULT pin pulled low during LED short, open, or thermal events.

Key Specifications

Availability

EV4425M-QB-00A is available at Aetrix Electronics and suitable for automotive LED headlight validation, interior lighting qualification, and industrial high-brightness LED driver development requiring stable component supply, repeatable test conditions, and EMI-compliant reference designs.

Supply support for EV4425M-QB-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 a focus on energy-efficient DC-DC conversion, LED drivers, and motor control solutions.

The EV4425M-QB-00A belongs to MPS's automotive-qualified evaluation board product line, designed specifically to accelerate development of AEC-Q100 Grade-1 LED lighting systems using their integrated synchronous buck LED drivers.

FAQ

What input voltage range does the EV4425M-QB-00A support?

The board accepts 4V to 36V DC input, matching the operating range of the MPQ4425MGQB IC. For optimal EMI performance above 24V, a damping capacitor must be added at the input terminals per the Quick Start Guide. Input connections can be made either to VIN/GND or VEMI/GND depending on filter path selection.

How is output current set and measured on this evaluation board?

Output current is set by three parallel 400mΩ 1% resistors (R5, R6, R7) at the LED– node, yielding I_OUT = 0.2V / (400mΩ || 400mΩ || 400mΩ) ≈ 1.5A. The 0.2V reference is internal to the MPQ4425MGQB; no external resistor is needed for basic operation, though RFB can be adjusted for lower currents per the provided table.

Does the board support PWM dimming, and how is it implemented?

Yes - PWM dimming is supported via the EN/DIM pin, which accepts an external 100Hz–2kHz square-wave clock. This directly modulates the LED current without altering regulation loop behavior. The board does not include an onboard PWM generator; users must supply the external clock signal as specified in the Quick Start Guide.

What fault conditions trigger the /FAULT pin, and how is it used?

The open-drain /FAULT pin pulls low during LED short circuit, LED open circuit, or thermal shutdown. It remains high otherwise. This signal is intended for system-level monitoring and requires an external pull-up resistor (not populated on board) to interface with host microcontrollers or fault loggers.

Is the EV4425M-QB-00A RoHS-compliant and AEC-Q100 qualified?

The board itself is RoHS-compliant (all components listed in BOM are lead-free), and its core IC - MPQ4425MGQB - is AEC-Q100 Grade-1 qualified (−40°C to +125°C ambient). Board-level qualification is not claimed; however, it is intended for validating automotive-grade LED driver designs per AEC-Q100 requirements.

Can the switching frequency be adjusted, and if so, how?

No - the MPQ4425MGQB operates at a fixed 2.2MHz switching frequency. There is no external frequency-setting resistor or pin. The board reflects this fixed-frequency behavior; no modifications alter FSW. Loop bandwidth is tuned via RT (R8 = 100kΩ), but switching frequency remains constant.