Monolithic Power Systems Inc. EV4423H-Q-00A

Overview

EV4423H-Q-00A from Monolithic Power Systems is an evaluation board for the MPQ4423HGQ synchronous step-down converter, delivering 3A continuous output at 3.3V from a 4–36V input. It integrates internal 85mΩ/55mΩ MOSFETs, operates at 410kHz (sync-capable up to 2.2MHz), and supports automotive cold-crank with high duty cycle. The board is fully assembled in a space-saving 3mm × 3mm QFN-8 footprint and includes power-good signaling, OCP hiccup mode, and thermal shutdown.

For engineers reviewing the EV4423H-Q-00A datasheet, EV4423H-Q-00A pinout, EV4423H-Q-00A application, or EV4423H-Q-00A equivalent, this board enables rapid validation of MPQ4423HGQ performance in automotive DC/DC conversion, industrial power rails, and distributed supply systems - especially where input transients, efficiency across load range, and clock synchronization are critical selection criteria.

Technical Context

The EV4423H-Q-00A implements current-mode control architecture using the MPQ4423HGQ IC, enabling fast transient response and simplified loop compensation. Its fixed 3.3V output (adjustable down to 0.8V via FB resistors R7/R8) is regulated with ±1% accuracy over line, load, and temperature.

Board-level design supports external clock synchronization (200kHz–2.2MHz), power-save mode at light load, and CLK_OUT signal generation inverted from SW for multi-phase interleaving. Input filtering uses five ceramic capacitors (including 10μF ×3 and 0.1μF ×4), while output employs dual 22μF X7R ceramics plus one 22μF electrolytic capacitor for low-impedance bulk storage.

Key Specifications

Availability

EV4423H-Q-00A is available at Aetrix Electronics and suitable for automotive infotainment power supplies, industrial PLC I/O modules, and distributed telecom power architectures requiring stable component supply, pre-validated layout, and production-ready reference design fidelity.

Supply support for EV4423H-Q-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, motor drivers, and LED lighting controllers.

The MPQ4423H product line targets automotive-grade buck regulators requiring AEC-Q100 qualification, wide input range, and robust protection - designed specifically for engine control units, ADAS camera modules, and body electronics subsystems.

FAQ

What input voltage range does the EV4423H-Q-00A support, and how is cold-crank handled?

The board accepts 4V to 36V DC input, validated down to 4.5V for automotive cold-crank events. Its MPQ4423HGQ controller maintains regulation and high duty cycle (>90%) below 6V, ensuring uninterrupted 3.3V output during battery sag without dropout or reset.

How do I adjust the output voltage from the default 3.3V?

Replace R8 (13kΩ) on the feedback divider network per the formula V_OUT = 0.792 × (1 + R7/R8). With R7 fixed at 41.2kΩ, selecting R8 adjusts V_OUT; e.g., 20kΩ yields ~2.5V. Recalculate compensation components (C4, R3, C2C) using MPS's online design tools or AN-101 application note.

Can the EV4423H-Q-00A synchronize to an external clock, and what are the timing constraints?

Yes - apply a 200kHz–2.2MHz square wave to the EN/SYNC pin. The internal clock rising edge aligns to the external clock's rising edge. Pulse width must be <1.7μs; logic high level must exceed 1.65V and remain ≤6V to avoid Zener clamp damage when driven directly.

What is the purpose of the CLK_OUT signal, and how should it be used?

CLK_OUT is an inverted copy of the SW node, intended for synchronizing secondary buck converters in multi-phase configurations. Its high-level voltage equals V_OUT, so interface voltage tolerance of downstream sync inputs must be verified - e.g., use a level shifter if V_OUT > 3.3V and slave IC expects 1.8V logic.

Does the board include thermal management provisions, and what is its maximum ambient operating temperature?

The board uses exposed-pad QFN-8 packaging for the MPQ4423HGQ and recommends ≥2 cm² of 2-oz copper pour connected to GND under U1. Tested performance sustains 3A at +25°C ambient; derating begins above +60°C ambient, with thermal shutdown activating at ~150°C junction temperature.

Is the EV4423H-Q-00A RoHS-compliant and AEC-Q100 qualified?

The MPQ4423HGQ IC is AEC-Q100 Grade 1 qualified (−40°C to +125°C) and RoHS-compliant. The EV4423H-Q-00A evaluation board itself carries no qualification status but uses only lead-free, RoHS-compliant passives and connectors per MPS documentation.