Monolithic Power Systems Inc. EVQ4573-QB-00A

Overview

EVQ4573-QB-00A from Monolithic Power Systems is a fully assembled and tested evaluation board for the MPQ4573GQBE-AEC1 synchronous buck converter, delivering 5V/2.5A output across a 5V–60V input range. It implements peak-current-mode control with selectable AAM or FCCM light-load operation, features remote EN and PG signaling, and supports configurable switching frequencies up to 2.2MHz for automotive power rail validation.

For engineers reviewing the EVQ4573-QB-00A datasheet, EVQ4573-QB-00A pinout, EVQ4573-QB-00A application, or EVQ4573-QB-00A equivalent, this board enables rapid characterization of high-voltage DC/DC conversion in AEC-Q100 Grade 1 environments - including cold-crank, load-dump, and transient response testing under real-world automotive supply conditions.

Technical Context

The EVQ4573-QB-00A implements the MPQ4573-AEC1 IC in fixed-frequency peak-current-mode control architecture, with internal 250mΩ high-side and 45mΩ low-side MOSFETs enabling efficient 5V regulation at up to 2.5A. Its AAM mode dynamically scales switching frequency below 400kHz under light loads to reduce gate and switching losses, while FCCM maintains constant frequency for predictable EMI behavior.

Board-level design includes an integrated 15μH power inductor (XAL6060-153MEB), input EMI filtering (CIN9 + L1), external feedback network (R4/R5/R6) for VOUT adjustment, and SYNCO clock output for phase synchronization with other converters. The 8.9cm × 8.9cm PCB supports VIN ramp-down to 4.5V and surge up to 60V without shutdown.

Key Specifications

Availability

EVQ4573-QB-00A is available at Aetrix Electronics and suitable for automotive infotainment power supplies, ADAS domain controller auxiliary rails, and industrial 24V-to-5V conversion requiring stable component supply across extended temperature and voltage transients.

Supply support for EVQ4573-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 power management ICs, with core expertise in DC/DC converters, LED drivers, and motor drivers for automotive, industrial, and computing applications.

The MPQ4573-AEC1 product line delivers AEC-Q100 Grade 1 qualified synchronous buck regulators targeting harsh automotive environments - designed specifically for front-end power conversion in engine control units, telematics, and camera modules where wide VIN, high efficiency, and reliability are mandatory.

FAQ

What input voltage transients does the EVQ4573-QB-00A support during testing?

The board is validated for cold-crank (VIN ramping from 24V → 6V → 10V), load-dump (24V → 58V → 24V), and VIN ramp-down to 4.5V with 2.5A load. These tests confirm robust operation under ISO 16750-2 automotive electrical stress conditions without latch-up or regulation loss.

How is output voltage adjusted on the EVQ4573-QB-00A?

VOUT is set by the R4/R5/R6 feedback divider network. R4 is fixed at 41.2kΩ; R5 is calculated using VOUT = 0.8V × (1 + R5/R4), and R6 provides loop compensation. Table 1 in the reference design lists values for 3.3V, 5V, 8V, and 12V outputs - all verified with <±1% accuracy at full load.

Does the board support synchronization with other converters?

Yes - the CCM/SYNCO pin outputs a 180° out-of-phase clock signal synchronized to the internal switching node. This allows precise interleaving with a second EVQ4573-QB-00A or compatible MPS buck controller to reduce input/output ripple and improve EMI performance in multi-rail systems.

What is the purpose of the NS components JP3 and JP4?

JP3 and JP4 are unpopulated jumper pads intended for optional external shielding above the inductor and IC. When populated with conductive tape or metal shield, they reduce radiated emissions - particularly critical in EMC-sensitive automotive test setups where conducted noise must meet CISPR 25 Class 5 limits.

Can the board operate in forced continuous conduction mode (FCCM)?

Yes - FCCM is enabled by grounding the MODE pin (U1 Pin 9). In FCCM, the converter maintains constant switching frequency regardless of load, eliminating low-frequency beat notes and ensuring predictable EMI spectra - essential for audio-sensitive or radar-co-located applications.

What is the measured efficiency at 24V input and 2.5A load?

At VIN = 24V, VOUT = 5V, fSW = 400kHz, and 2.5A load in AAM mode, the board achieves 92.3% efficiency (measured per Figure 7, Rev. 1.0). Power loss is 1.08W, dominated by conduction loss in the 45mΩ low-side MOSFET and inductor DCR (43.75mΩ).