Monolithic Power Systems Inc. EVQ4323-D-00A

Overview

EVQ4323-D-00A from Monolithic Power Systems is a fully assembled and tested evaluation board for the MPQ4323 AEC-Q100-qualified synchronous step-down converter, supporting 3.3V–36V input, 5V/3A output, 2.2MHz switching frequency, 1μA shutdown quiescent current, and automotive load-dump (42V) tolerance.

For engineers reviewing the EVQ4323-D-00A datasheet, EVQ4323-D-00A pinout, EVQ4323-D-00A application, or EVQ4323-D-00A equivalent, this board enables rapid validation of MPQ4323 performance in automotive power systems, cold-crank operation, low-I_Q battery-powered modules, and CISPR25 Class 5 EMI-compliant designs.

Technical Context

The EVQ4323-D-00A implements the MPQ4323 IC in QFN-12 (2mm×3mm) package with wettable flanks, featuring peak-current-mode control, frequency foldback at startup, open-drain power-good (PG) signaling (94.5–105.5% V_OUT window), and thermal shutdown protection.

It supports configurable switching frequency (350kHz–2.5MHz) via external resistor on FREQ pin, adjustable output voltage via FB divider (e.g., 5V with R5=100kΩ/R6=19.1kΩ), and high-duty-cycle/low-dropout mode for 3.3V_IN cold-crank conditions with 5V_OUT.

Key Specifications

Availability

EVQ4323-D-00A is available at Aetrix Electronics and suitable for automotive ADAS camera modules, body control units, infotainment head units, and telematics control units requiring stable component supply and AEC-Q100-validated reference designs.

Supply support for EVQ4323-D-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 power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPQ4323 product line targets automotive power conversion applications requiring AEC-Q100 qualification, wide input range, ultra-low I_Q, and integrated high-side/low-side MOSFETs in thermally enhanced QFN packages.

FAQ

What input voltage range does the EVQ4323-D-00A support?

The board supports 3.3V to 36V DC input, verified across cold-crank (3.3V), nominal (12V/24V), and load-dump (up to 42V transient) conditions. Input capacitors include 4.7μF ×2 ceramic (C1A/C1B), 1nF/10nF high-frequency bypass (CIN1/CIN2), and 22μF polymer bulk (CIN5) for robust transient response.

How is output voltage configured on this evaluation board?

V_OUT is set via an external resistor divider on the FB pin: R5 = 100kΩ (fixed), R6 = 19.1kΩ for 5V output. Equation V_OUT = 0.8V × (1 + R5/R6) applies. The board includes solder pads for alternate R6 values to support 1V–5.8V outputs per MPQ4323 datasheet specifications.

Does the EVQ4323-D-00A include EMI mitigation features?

Yes - it integrates a 3A magnetic bead (FB1, Wurth 742792063) on the input path, optimized layout with split ground planes and minimized high-di/dt loops, and has passed CISPR25 Class 5 conducted and radiated emissions testing (150kHz–1GHz) without external filters.

Can the switching frequency be adjusted, and how?

Yes - frequency is set by a resistor between FREQ and GND. Default 2.2MHz uses no external resistor; adding 13.3kΩ yields 2.5MHz, 15kΩ yields 2.2MHz, 34.8kΩ yields 1MHz, and 86.6kΩ yields 415kHz. Table on page 6 of the reference document lists exact R_FREQ/f_SW pairs.

What thermal performance is measured on the EVQ4323-D-00A?

At 3A load with no forced airflow, case temperature rise is 54.5°C above ambient (T_CASE = 37.1°C at 1.5A). The MPQ4323's QFN-12 (2mm×3mm) package with wettable flanks ensures efficient heat transfer to PCB copper, validated under continuous 3A operation at 12V_IN/5V_OUT.

Is the enable (EN) function accessible and what are its thresholds?

Yes - EN is brought out to a test point. Logic-high (>1.02V) enables regulation; logic-low (<0.85V) disables it with 1μA shutdown current. If unused, EN may be tied directly to VIN. The board includes a 0Ω jumper (R4) to simplify this connection.

What is the purpose of the PG (power good) signal, and how is it implemented?

PG is an open-drain output asserting when V_OUT is within ±5.5% of target (e.g., 4.725V–5.275V for 5V). It drives external monitoring circuits or microcontroller interrupts. On this board, PG connects to a test point and is verified in startup/shutdown waveforms (pages 12–14 of reference doc).