Monolithic Power Systems Inc. EV2639A-R-00B

Overview

EV2639A-R-00B from Monolithic Power Systems is a reference design board for the MP2639AGR switching battery charger IC, enabling 2-cell Li-ion/Li-polymer charging with 2.5A current, 4.0–5.75V input range, 8.4V charge voltage (±0.5%), and integrated input-current/voltage-based power management. It supports USB-compliant charging, thermal regulation, battery temperature monitoring via NTC, and 4-LED fuel gauge indication for portable power stations and tablets.

For engineers reviewing the EV2639A-R-00B datasheet, EV2639A-R-00B pinout, EV2639A-R-00B application, or EV2639A-R-00B equivalent, this evaluation board provides verified layout, BOM, and functional validation of MP2639AGR's dual-loop (input current + input voltage) power path control, thermal shutdown, and 2.5A 2-cell charging under real-world USB and adapter sources.

Technical Context

The EV2639A-R-00B implements MP2639AGR's full charging stack in a compact 3cm × 2.8cm PCB, featuring programmable input current limit (3A via RILIM), input voltage clamp (4.49V via R3/R4), and charge current (2.5A via RISET). It validates the IC's dual-mode power management-prioritizing system load over battery charge when input source capability is constrained.

Board-level protection includes input over-voltage, battery over-voltage (8.4V), thermal shutdown, NTC-based battery temperature monitoring, and charge timer backup. The 4-LED driver circuit maps battery voltage to discrete state-of-charge levels using fixed resistor dividers and U1's status outputs.

Key Specifications

Availability

EV2639A-R-00B is available at Aetrix Electronics and suitable for power station applications, tablet battery management systems, and mobile internet device development requiring stable component supply, validated reference designs, and rapid prototyping support.

Supply support for EV2639A-R-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 mixed-signal ICs for power management, motor drive, and automotive applications.

The MP2639A product line targets portable and battery-powered systems requiring robust, USB-aware, dual-loop (input current + input voltage) charging control for multi-cell Li-ion packs with integrated safety and fuel gauging.

FAQ

What is the primary function of the EV2639A-R-00B board?

This board is a fully assembled, tested reference design for the MP2639AGR IC. It demonstrates and validates 2-cell Li-ion/Li-polymer charging with 2.5A current, dual-loop input power management, thermal regulation, NTC-based temperature monitoring, and 4-LED fuel gauge functionality-all implemented per MPS's recommended layout and BOM.

Can the EV2639A-R-00B be used with non-USB 5V sources?

Yes. The board accepts any 4.0–5.75V DC input, including USB ports, 5V wall adapters, or bench supplies. Input voltage clamp (4.49V) and current limit (3A) remain active regardless of source type, ensuring consistent behavior across USB and non-USB inputs.

How is battery temperature monitored on this board?

Using an NTC thermistor (RNTC1) connected to the MP2639AGR's NTC pin. The board implements a voltage divider (RNTC1 + R4) that scales the NTC resistance into the IC's analog input range, enabling real-time battery temperature tracking and charge suspension if thresholds are exceeded.

What protections are implemented on the EV2639A-R-00B?

The board enables all MP2639AGR protections: input over-voltage lockout (OVP), battery over-voltage cutoff (8.4V), thermal shutdown (via die temperature sensing), charge timer timeout (prevents indefinite charging of deeply discharged cells), and NTC fault detection. These are hardware-verified in the reference design.

Is the 4-LED fuel gauge calibrated to actual battery capacity?

No-it is voltage-based only. The LEDs indicate approximate state-of-charge using four fixed battery voltage thresholds (e.g., <7.6V, 7.6–7.9V, 7.9–8.2V, >8.2V), derived from MP2639AGR's VBAT monitor and comparator outputs. It does not perform coulomb counting or impedance tracking.

Does the board support system load powering while charging?

Yes. The MP2639AGR implements a dynamic power-path manager that prioritizes system load over battery charging when input power is limited. The EV2639A-R-00B validates this behavior-e.g., under weak USB sources, it reduces charge current to maintain system voltage above 4.49V.