Monolithic Power Systems Inc. EVQ4323-D-01A

Overview

EVQ4323-D-01A from Monolithic Power Systems is a fully assembled and tested evaluation board for the MPQ4323GDE-AEC1 synchronous step-down converter, supporting 3.3V–36V input, 5V/3A output, 2.2MHz switching frequency, AEC-Q100 qualification, and 1μA shutdown quiescent current. It enables rapid validation of automotive-grade buck regulation in cold-crank, load-dump, and EMI-sensitive environments.

For engineers reviewing the EVQ4323-D-01A datasheet, EVQ4323-D-01A pinout, EVQ4323-D-01A application, or EVQ4323-D-01A equivalent, this board delivers production-relevant test data-including CISPR25 Class 5 conducted/radiated emissions, thermal rise at 3A, Bode plot stability margins (70.8° phase margin), and low-dropout mode behavior down to 3.3V input-directly traceable to the MPQ4323GDE-AEC1 QFN-12 IC.

Technical Context

The EVQ4323-D-01A implements the MPQ4323GDE-AEC1's peak current mode control architecture with integrated high-side and low-side MOSFETs, enabling 3A continuous output from a 3.3V–36V input range and 42V load-dump tolerance. Its configurable 350kHz–2.5MHz switching frequency is set via external resistor on the FREQ pin, and it supports programmable output voltage (e.g., 3.3V or 5V) using a precision feedback divider.

Key operational features validated on this board include power-good (PG) monitoring with ±5.5% window, frequency foldback during start-up, thermal shutdown, and seamless transition into low-dropout (LDO) mode during automotive cold-crank (VIN = 3.3V). All measurements-including efficiency curves, line/load regulation, and EMI compliance-are captured under real-world conditions (TA = 25°C, no forced airflow).

Key Specifications

Availability

EVQ4323-D-01A is available at Aetrix Electronics and suitable for automotive ECU development, ADAS camera power supply validation, and infotainment head-unit DC-DC qualification requiring stable component supply, pre-tested layout reference, and AEC-Q100-aligned test data.

Supply support for EVQ4323-D-01A 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 core expertise in DC-DC conversion, motor drivers, and LED lighting controllers.

The MPQ4323 product line is designed specifically for automotive power rails-delivering robust, AEC-Q100-qualified buck regulation with integrated MOSFETs, ultra-low IQ, and comprehensive fault protection for engine control, body electronics, and safety-critical systems.

FAQ

What input voltage range does the EVQ4323-D-01A support?

The board supports 3.3V to 36V DC input, matching the MPQ4323GDE-AEC1's operating range. It withstands 42V transients per load-dump testing and maintains regulation down to 3.3V during cold-crank, verified by waveform capture in the test report (pages 15–16).

Can I adjust the output voltage on this evaluation board?

Yes. The board ships with R5 = 100kΩ and R6 = 31.6kΩ for 5V output, but R6 can be replaced to set other voltages (e.g., 3.3V uses R6 = 26.7kΩ). Equation (1) in the Quick Start Guide provides exact calculation: VOUT = 0.8V × (1 + R5/R6).

Does the EVQ4323-D-01A include EMI filtering components?

Yes. It integrates an EMI filter stage with magnetic bead FB1 (Wurth 742792063), input ceramic and polymer capacitors (CIN1–CIN5), and optimized PCB layout per MPS's CISPR25 Class 5 test results (pages 10–11), achieving compliance without external add-ons.

How is the switching frequency configured?

Frequency is set by connecting a resistor between FREQ and GND. The board includes R3 (86.6kΩ) for 415kHz and provisions for R8/R9 (47.5kΩ/18.2kΩ) to achieve 2.2MHz. The fSW vs. RFREQ curves (page 8) confirm linear tuning across 350kHz–2.5MHz.

Is thermal performance characterized on this board?

Yes. Thermal imaging data shows 54.5°C case temperature rise at 3A, 12V input, no forced airflow (page 8). This validates the QFN-12 package's thermal path and copper-thick (2oz) PCB stack-up for sustained automotive operation.

What protection features are verified on the EVQ4323-D-01A?

Test waveforms confirm short-circuit protection (SCP) entry/recovery, PG assertion/deassertion during start-up/shutdown (pages 12–14), thermal shutdown activation, and frequency foldback during soft-start-all directly tied to MPQ4323GDE-AEC1's internal circuitry and not added externally.