Monolithic Power Systems Inc. EV2499A-QB-00A

Overview

EV2499A-QB-00A from Monolithic Power Systems is an evaluation board for the MP2499AGQB synchronous step-down converter IC, designed to validate 5V/2.4A output operation from a 12V input across a 5–36V input range. It integrates internal 85mΩ/55mΩ MOSFETs, operates at 270kHz default switching frequency, and delivers stable regulation with current-mode control and thermal shutdown protection in automotive and USB charging applications.

For engineers reviewing the EV2499A-QB-00A datasheet, EV2499A-QB-00A pinout, EV2499A-QB-00A application, or EV2499A-QB-00A equivalent, this board enables rapid validation of MP2499AGQB's load transient response, efficiency at 2.4A, external clock synchronization (200kHz–2.4MHz), soft-start behavior, and adjustable current limit via R3.

Technical Context

The EV2499A-QB-00A implements the MP2499AGQB IC in a two-layer PCB layout measuring 5.5cm × 1.4cm × 1.1cm, with a QFN-13 (2.5mm × 3mm) footprint for U1. It supports input voltages from 5V to 36V and regulates a fixed 5V output at up to 2.4A continuous current using an 11μH toroidal inductor (L1) and a coordinated capacitor network including 10μF ceramic (C1/C1A), 100μF electrolytic (C1B), and 100μF polymer (C2A) units.

Control features include EN/SYNC pin functionality for enable/disable (1.4V/1.25V thresholds) and external clock synchronization, internal soft-start, output line drop compensation, and hiccup-mode over-current protection triggered by the 40mΩ current-sense resistor (R3). The board uses no jumpers or DIP switches-configuration is set by fixed BOM values.

Key Specifications

Availability

EV2499A-QB-00A is available at Aetrix Electronics and suitable for USB charging validation, automotive cigarette lighter adapter development, and USB PD auxiliary power rail characterization requiring stable component supply and repeatable lab performance.

Supply support for EV2499A-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 analog and power ICs, with core expertise in DC-DC conversion, motor drivers, and LED lighting controllers.

The MP2499A product line targets high-efficiency, wide-input industrial and automotive power supplies, emphasizing minimal external components, robust protection, and seamless integration into compact USB and vehicle-mounted power systems.

FAQ

What input voltage range is supported on the EV2499A-QB-00A?

The board supports 5 V to 36 V continuous input, verified per datasheet test conditions at 12 V. Operation below 5 V is not guaranteed due to MP2499AGQB's under-voltage lockout threshold, and inputs above 36 V exceed absolute maximum ratings and risk permanent damage.

How is output voltage set - is it adjustable?

Output is fixed at 5 V by the internal feedback network of the MP2499AGQB IC. No external resistor divider is populated; R5 is 0 Ω and R6 is 300 kΩ, confirming factory-configured 5 V regulation. Adjusting VOUT requires replacing U1 with a different variant or modifying feedback resistors per datasheet guidelines.

Can the EV2499A-QB-00A synchronize to an external clock?

Yes - the EN/SYNC pin accepts a 200 kHz to 2.4 MHz CMOS-level clock signal. When driven externally, the MP2499AGQB locks its switching frequency to the applied clock, enabling EMI spread-spectrum control or synchronization with other converters in multi-rail systems.

What is the role of R3 (40 mΩ) on this board?

R3 serves as the current-sense resistor for accurate output current limiting. Its 40 mΩ value sets the OCP threshold at ≈2.4 A (V_ocp = 100 mV typical), matching the rated output current. It directly interfaces with the MP2499AGQB's internal current-limit comparator and enables hiccup-mode recovery.

Does the board include thermal management features beyond shutdown?

Yes - the QFN-13 package of U1 is soldered to a dedicated thermal pad connected to internal copper pours on both layers. The PCB layout includes thermal vias beneath the IC and low-thermal-resistance traces to C1B and C2A, enabling sustained 2.4 A operation at +25°C ambient without forced airflow.

Is the USB port on the board functional for data or only power delivery?

The USB Type-A connector (Wurth 61400416021) is wired exclusively for power delivery - VBUS and GND only. No D+ or D− lines are routed or terminated; it serves as a mechanical and electrical interface for connecting downstream USB devices to the 5 V output, compliant with USB Dedicated Charging Port (DCP) signaling.