Monolithic Power Systems Inc. EV2321-D-00A

Overview

EV2321-D-00A from Monolithic Power Systems is an evaluation board designed to demonstrate the MP2321GD synchronous step-down converter, a 2A, 4–19V input, constant-on-time DC/DC regulator with 40μA quiescent current, 1.2V output at 12V input, and 500kHz switching frequency in a 2mm×3mm QFN14 package.

For engineers reviewing the EV2321-D-00A datasheet, EV2321-D-00A pinout, EV2321-D-00A application, or EV2321-D-00A equivalent, this board enables rapid validation of MP2321GD's light-load efficiency, forced-PWM/auto-PFM mode behavior, soft-start programmability, and power-good signaling under real-world load transients and thermal conditions.

Technical Context

The EV2321-D-00A implements the MP2321GD IC in a fully populated, optimized 4-layer PCB layout with 2.2μH power inductor (Wurth 744311220), dual 22μF output capacitors (Murata GRM31ER71E226KE15L and GRM31CR71A226KE15L), and precision feedback resistors enabling 1.2V output regulation at 2A continuous load.

It supports configurable operating modes via R6 (forced PWM) or R7 (auto PFM/PWM), includes a programmable soft-start network (C3/R3), and integrates a power-good indicator circuit tied to the MP2321GD's PG pin - all validated per MPS Rev.1.0 test conditions: VIN=12V, VOUT=1.2V, TA=25°C.

Key Specifications

Availability

EV2321-D-00A is available at Aetrix Electronics and suitable for SSD power management, tablet PMIC validation, and battery-operated embedded system development requiring stable component supply, pre-validated thermal performance, and production-ready layout reference.

Supply support for EV2321-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 analog and mixed-signal semiconductor company specializing in high-efficiency power management ICs, with design centers in the US, China, and Taiwan.

The MP2321 product line targets ultra-low-quiescent-current DC/DC conversion for portable and always-on applications, emphasizing COT control, small QFN packaging, and integrated protection for space-constrained battery-powered designs.

FAQ

What input voltage range is supported on the EV2321-D-00A?

The board is configured and tested for 12V input but supports the full 4V–19V range of the MP2321GD IC. Input capacitors (C1, Cb) and layout are rated for 25V, allowing safe operation up to 19V with appropriate derating of the 2.2μH inductor's saturation current.

How do I configure forced PWM versus auto PFM/PWM mode?

Install jumper R6 (100kΩ) and leave R7 unpopulated for forced PWM mode; install R7 (180kΩ) and omit R6 for auto PFM/PWM mode. Mode selection is implemented via the MP2321GD's MODE pin, and both configurations are verified in the schematic and BOM.

Does the board include a power-good indicator?

Yes - the MP2321GD's open-drain PG pin is routed to a test point and pulled up to 3.3V via R4. The signal asserts high when output voltage is within ±7.5% of regulation, providing system-level power sequencing feedback.

What is the purpose of the 15nF capacitor (C3) on the board?

C3 (15nF) forms part of the soft-start timing network with R3 (100kΩ), setting a ~1.5ms soft-start delay. This limits inrush current during startup and prevents output overshoot when powering sensitive downstream loads like FPGA cores or DRAM.

Can the output voltage be adjusted, and how?

Yes - the output is set to 1.2V using R3 (100kΩ) and R4 (100kΩ) in the feedback divider. To adjust, replace R4 with a value calculated as R4 = R3 × (VOUT / 0.6V − 1), since the MP2321GD's internal reference is 0.6V and FB pin draws <100nA.

Is thermal performance characterized on this board?

Yes - the board uses a 4-layer stackup with inner layers as solid ground planes, and the MP2321GD QFN14 package is soldered directly to thermal pads connected to internal copper pours. Test data in the user guide confirms thermal shutdown activates above 150°C junction temperature under 2A load.