Monolithic Power Systems Inc. EVQ4425A-QB-00A

Overview

EVQ4425A-QB-00A from Monolithic Power Systems is a fully assembled and tested evaluation board for the MPQ4425A-AEC1/MPQ4425A synchronous step-down LED driver IC, supporting 4V–36V input and delivering up to 1.5A constant LED current at 2.2MHz switching frequency with CISPR25 Class 5 EMI compliance and AEC-Q100 Grade-1 qualification for automotive lighting.

For engineers reviewing the EVQ4425A-QB-00A datasheet, EVQ4425A-QB-00A pinout, EVQ4425A-QB-00A application, or EVQ4425A-QB-00A equivalent, this board enables rapid validation of MPQ4425A-based LED driver designs-especially for PWM dimming, fault monitoring (/FAULT), thermal shutdown, and high-efficiency CCM operation in harsh automotive environments.

Technical Context

The EVQ4425A-QB-00A implements the MPQ4425A-AEC1 IC in QFN-13 (2.5mm × 3mm) package with integrated 85mΩ high-side and 50mΩ low-side MOSFETs, enabling compact 36V/1.5A LED driver solutions without external power switches. It operates in forced continuous conduction mode (CCM) with 0.2V reference voltage and valley-current OCP detection.

Board-level design includes dual 2.2µH power inductors (L2/L3), 240nH EMI filter inductor (L4), input/output ceramic and electrolytic capacitors, and configurable feedback resistor (RFB) network for precise ILED setting. EMI performance is validated per CISPR25 Class 5 across conducted and radiated bands (150kHz–1GHz).

Key Specifications

Availability

EVQ4425A-QB-00A is available at Aetrix Electronics and suitable for automotive LED headlamp modules, interior ambient lighting systems, and commercial vehicle DRL/position lamp designs requiring stable component supply, EMI-certified reference hardware, and AEC-Q100-compliant validation platforms.

Supply support for EVQ4425A-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 core expertise in DC/DC conversion, LED drivers, motor drivers, and automotive-grade power solutions.

The MPQ4425A product line delivers AEC-Q100 Grade-1 qualified synchronous buck LED drivers optimized for automotive exterior lighting, emphasizing high efficiency (>95% at 12V→3.2V/1.5A), robust fault protection, and ultra-low EMI for system-level EMC certification.

FAQ

What is the primary IC used on the EVQ4425A-QB-00A board?

The board integrates the MPQ4425AGQB-AEC1 - a 36V, 1.5A synchronous step-down LED driver in QFN-13 (2.5mm × 3mm) package with integrated 85mΩ/50mΩ MOSFETs, 2.2MHz switching, and AEC-Q100 Grade-1 qualification. It is pre-soldered and fully functional.

How is LED current set and adjusted on this evaluation board?

LED current is set by the external feedback resistor RFB using the formula I_LED = 0.2V / R_FB. The board ships with RFB = 133mΩ (1%) for 1.5A output. Values for 0.5A (400mΩ) and 1A (200mΩ) are also documented in the Quick Start Guide for flexible prototyping.

Does the board support PWM dimming, and what is the required signal format?

Yes - PWM dimming is supported via the EN/DIM pin. Apply an external clock signal between 100Hz and 2kHz with logic-high ≥1.45V and logic-low ≤1V. The board does not include an onboard PWM generator; external microcontroller or signal source is required.

What fault protections are implemented and how are they indicated?

The board monitors LED open/short and thermal shutdown conditions through the /FAULT pin (active-low open-drain). When asserted, /FAULT pulls low and can be read by host controller. This signal is routed to a 2.54mm test point for oscilloscope or logic analyzer monitoring.

Is input EMI filtering included, and how should high-voltage inputs be handled?

Yes - the board includes a 240nH EMI filter inductor (L4) and input capacitor bank (CIN1–CIN7). For inputs ≥24V or cable lengths >0.5m, MPS recommends adding an external damping capacitor (e.g., 10µF ceramic) directly across VEMI and GND to suppress ringing and improve conducted EMI margin.

Can this board be used for non-automotive applications?

Yes - while designed for AEC-Q100 Grade-1 compliance and CISPR25 Class 5 EMI, the board's 4V–36V input, 1.5A output, and 2.2MHz operation make it suitable for industrial signage, architectural lighting, and agricultural equipment where robustness and low-noise operation are critical.