Monolithic Power Systems Inc. EV4423-Q-00A

Overview

EV4423-Q-00A from Monolithic Power Systems is an evaluation board for the MPQ4423GQ synchronous step-down converter IC, configured to deliver 3.3V/3A output from a 4–30V continuous (36V transient) input. It integrates the QFN-8 packaged MPQ4423GQ with 85mΩ/55mΩ internal MOSFETs, operates at 410kHz default switching frequency, and supports external clock synchronization from 200kHz to 2.2MHz for automotive and industrial power system validation.

For engineers reviewing the EV4423-Q-00A datasheet, EV4423-Q-00A pinout, EV4423-Q-00A application, or EV4423-Q-00A equivalent, this board enables rapid functional verification of the MPQ4423GQ's load dump tolerance, cold-crank capability, power-good signaling, and thermal shutdown behavior under real-world DC/DC design constraints.

Technical Context

The EV4423-Q-00A implements a current-mode, synchronous buck topology centered on the MPQ4423GQ controller IC. It uses a 10μH shielded inductor (XAL5050-103ME), 2×22μF ceramic output capacitors, and precision feedback resistors (R7=41.2kΩ, R8=13kΩ) to set VOUT=3.3V with 0.792V reference.

Board-level features include dual 5-pin golden-pin headers for VIN/VOUT/GND/EN/PG and CLK_OUT/SYNC/PG/GND/EN, enabling direct oscilloscope probing, external clock injection, and power-good monitoring without soldering. The layout follows MPS-recommended thermal and EMI practices for QFN-8 DC/DC converters.

Key Specifications

Availability

EV4423-Q-00A is available at Aetrix Electronics and suitable for automotive infotainment power validation, industrial PLC I/O module testing, and distributed 3.3V rail development requiring stable component supply and documented reference performance.

Supply support for EV4423-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 analog semiconductor company specializing in high-efficiency power management ICs, with core expertise in DC/DC conversion, motor drivers, and LED lighting controllers.

The MPQ4423 product line targets automotive-grade power supplies requiring AEC-Q100 qualification, wide input range, and robust transient immunity - designed specifically for body electronics, ADAS sensors, and gateway ECUs.

FAQ

What input voltage range is validated on the EV4423-Q-00A board?

The board is tested and specified for 4–30V continuous operation and withstands 36V transients for up to 100ms, meeting automotive load dump requirements per ISO 7637-2. Input filtering uses six parallel 10μF ceramic capacitors to maintain stability during fast transients.

How is the 3.3V output voltage set and can it be adjusted?

VOUT is set by resistor divider R7 (41.2kΩ) and R8 (13kΩ) to achieve 3.3V using the MPQ4423GQ's 0.792V feedback reference. Output is adjustable down to 0.8V by recalculating R8 per the formula VOUT = 0.792 × (1 + R7/R8); compensation network must be re-optimized per datasheet guidelines.

Does the board support external clock synchronization, and what are the signal requirements?

Yes - the EN/SYNC pin accepts 200kHz–2.2MHz external clocks with <1.7μs pulse width. Synchronization aligns the internal clock rising edge to the external clock rising edge, enabling multi-phase operation or EMI spread-spectrum control without modifying hardware.

What thermal performance can be expected during 3A continuous operation?

At TA=25°C, 12V input, and 3.3V/3A output, the MPQ4423GQ junction temperature rises to ~95°C on this board. Thermal shutdown activates above 150°C, and the QFN-8 package's exposed pad is fully soldered to a 2-layer 1oz copper thermal pad per MPS layout recommendations.

Is the Power-Good (PG) signal actively driven or open-drain, and what is its timing behavior?

PG is an open-drain output with internal 10kΩ pull-up to VOUT. It asserts high after VOUT reaches 90% of target and remains valid for ≥100ms; it de-asserts within 10μs of VOUT dropping below 85%. This meets standard processor reset timing requirements.

Can the board be used to evaluate cold-crank performance, and what minimum input voltage is supported?

Yes - the MPQ4423GQ supports 100% duty cycle operation down to 2.5V input, enabling validation at automotive cold-crank conditions (e.g., 4.5V for 15s). The board maintains regulation and PG assertion down to VIN=4V, with no external components modified.