Monolithic Power Systems Inc. EV2603EJ-00B

Overview

EV2603EJ-00B from Monolithic Power Systems is a fully assembled and tested evaluation board for the MP2603EJ single-cell linear Li-ion battery charger IC, supporting 50–150 mA programmable CC/CV charging, 4.2 V output voltage, and charge status indication via green LED. It targets compact portable electronics requiring low-cost, minimal-BOM battery charging solutions.

For engineers reviewing the EV2603EJ-00B datasheet, EV2603EJ-00B pinout, EV2603EJ-00B application, or EV2603EJ-00B equivalent, this board enables rapid validation of MP2603EJ-based charging circuits in Bluetooth headsets, MP3 players, mini PDAs, and digital cameras - with no external sense resistor or reverse-blocking diode required.

Technical Context

The EV2603EJ-00B implements the MP2603EJ IC in a TSOT23-5 package, configured for fixed 4.2 V CV regulation and adjustable CC current (50–150 mA) via R1 (2.49 kΩ default). Input enable threshold is 3.5 V; operation ceases when VIN drops below that level.

It integrates trickle-charge mode for deeply discharged batteries, <1 µA reverse battery leakage, and 0.75% V_BATT accuracy. The green LED (SML-LX0603GW-TR) drives CHGZ open-drain output to indicate active charging state.

Key Specifications

Availability

EV2603EJ-00B is available at Aetrix Electronics and suitable for Bluetooth headset development, MP3 player power subsystem validation, and digital camera battery charging design requiring stable component supply and pre-validated reference implementation.

Supply support for EV2603EJ-00B 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, battery management, and motor control.

The MP2603 product line delivers cost-optimized, integrated linear Li-ion chargers for space-constrained portable devices where simplicity, low BOM count, and guaranteed 4.2 V CV accuracy are critical.

FAQ

What is the purpose of the R2 position on the EV2603EJ-00B board?

R2 is marked "Do Not Stuff" in the bill of materials. It is a reserved location with no populated component and serves no functional role in the default configuration. Its presence allows optional customization or failure-analysis probing but does not affect standard operation or charging behavior.

Can the EV2603EJ-00B charge batteries other than single-cell Li-ion?

No. The board is strictly configured for 4.2 V CV termination and CC/CV algorithm optimized for single-cell Li-ion chemistry. It lacks voltage or algorithm reconfiguration capability and is not suitable for LiFePO₄, NiMH, or multi-cell stacks without hardware modification and firmware-level control - which is not supported.

How is charge current adjusted on the EV2603EJ-00B?

Charge current is set by resistor R1 using the formula I_CHG = 150 mA × (2.49 kΩ / R1). With the default 2.49 kΩ resistor, I_CHG = 150 mA. Replacing R1 with another value (e.g., 4.99 kΩ) scales current linearly down to 75 mA, per MP2603EJ's internal current-sense architecture.

What does the green LED indicate during operation?

The green LED illuminates only when the MP2603EJ asserts its CHGZ pin low - signaling active constant-current or constant-voltage charging. It turns off when charging completes, battery is absent, or input voltage falls below 3.5 V, providing unambiguous real-time status without external monitoring.

Is an external reverse-blocking diode required for safe operation?

No. The MP2603EJ IC inherently prevents reverse current flow from battery to input, delivering <1 µA reverse leakage. This eliminates the need for an external Schottky or MOSFET blocking device, reducing BOM count, board area, and forward-voltage loss in the power path.