Monolithic Power Systems Inc. EV3120-J-00A

Overview

EV3120-J-00A from Monolithic Power Systems is a fully assembled evaluation board for the MP3120DJ synchronous boost converter IC, enabling rapid validation of 3.3V output generation from input voltages as low as 0.85V (e.g., single-cell alkaline or Li battery), with 1.1MHz fixed-frequency operation, true output disconnect, and inrush current limiting. It supports up to 1.2A output current and integrates all critical passive components including a 4.7μH shielded inductor and ceramic capacitors.

For engineers reviewing the EV3120-J-00A datasheet, EV3120-J-00A pinout, EV3120-J-00A application, or EV3120-J-00A equivalent, this board provides verified reference design implementation, efficiency vs. load curves (up to 96% at 100mA), startup/shutdown waveforms, short-circuit recovery behavior, and FB resistor configuration guidance for custom VOUT scaling.

Technical Context

The EV3120-J-00A implements the MP3120DJ's current-mode control architecture with internal compensation, enabling stable regulation without external loop components. Its TSOT23-6 footprint and integrated P-channel MOSFET enable true output-to-input disconnect during shutdown, eliminating reverse leakage paths in battery-powered systems.

Board-level features include soft-start via internal timing, overcurrent protection triggered by IL sensing, and automatic recovery from output short circuits. The fixed 1.1MHz switching frequency allows compact magnetics and reduces EMI filtering requirements compared to lower-frequency boost solutions.

Key Specifications

Availability

EV3120-J-00A is available at Aetrix Electronics and suitable for battery-powered portable electronics development, power management validation, and DC-DC topology benchmarking requiring stable component supply, pre-characterized performance data, and production-representative layout.

Supply support for EV3120-J-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, LED drivers, and motor control solutions.

The MP3120DJ product line targets ultra-low-voltage battery-powered applications where startup from sub-1V sources, output disconnect, and minimal external component count are critical - such as wearables, wireless sensors, and energy-harvesting subsystems.

FAQ

What input voltage range is supported, and can it start from a nearly depleted AA battery?

Yes. The EV3120-J-00A supports 0.85V–5V input, verified to start reliably from 0.85V - matching the minimum discharge voltage of a single alkaline AA cell. Startup waveforms (Page 3) confirm clean EN-triggered turn-on at VIN = 2.5V, and the MP3120DJ's internal charge pump enables gate drive below 1V.

How is output voltage adjusted, and what is the feedback reference voltage?

VOUT is set by an external resistor divider on the FB pin. The internal reference is precisely 1.21V (confirmed in Quick Start Guide formula). For example, replacing R1/R5 (20kΩ each) with 10kΩ/10.5kΩ yields ~3.6V output. Layout accommodates 0603 resistors for easy rework.

Does the board provide true output disconnect, and how is it implemented?

Yes. When EN is low, the MP3120DJ's internal P-channel MOSFET turns off completely, breaking the path between VOUT and VIN. This eliminates reverse current flow - critical for battery backup systems. Test waveforms (Page 4, "VIN Shut down") show VOUT decaying independently with no coupling to VIN.

What inductor and capacitors are used, and are they production-grade?

The board uses Wurth 744311470 (4.7μH, 7A, 19.5mΩ DCR) and TDK C3216X7R1E106K (10μF/25V) and C3216X7R1C475K (4.7μF/16V) - all automotive-grade, SMD, and qualified for industrial temperature ranges. Bill of Materials (Page 2) lists full manufacturer part numbers and package codes.

Is short-circuit protection latched or auto-recovering?

Auto-recovering. Under sustained short-circuit (VIN = 3V), the board cycles into hiccup mode: SW pulses cease for ~20ms, then attempt restart. Waveforms (Page 4) show repeated recovery attempts until fault clears - preventing thermal damage while maintaining system awareness.

Can this board be used with lithium coin cells like CR2032?

Yes, within limits. A CR2032 delivers ~3V open-circuit but sags under load; the board operates stably at VIN ≥ 0.85V and handles up to 1.2A peak. However, typical CR2032 continuous discharge is ≤15mA - so the board is suitable for low-duty-cycle pulse loads (e.g., sensor wake-up bursts), not sustained 500mA draws.