Monolithic Power Systems Inc. EV2639C-R-00A

Overview

EV2639C-R-00A from Monolithic Power Systems is a reference design board for the MP2639C integrated 2-cell Li-ion/Li-polymer switching charger and bidirectional power manager. It implements boost-mode charging (2.5A at 5V input) and buck-mode discharge (5A at 5V output), with integrated fuel-gauge LED drivers, thermal shutdown, battery temperature monitoring, and charge timer protection. Used in portable power-bank applications requiring dual-direction energy flow.

For engineers reviewing the EV2639C-R-00A datasheet, EV2639C-R-00A pinout, EV2639C-R-00A application, or EV2639C-R-00A equivalent, this evaluation board enables rapid validation of MP2639C's charge/discharge sequencing, input-current limiting, battery voltage regulation, and system-power handover behavior under real-world USB-powered and battery-backed conditions.

Technical Context

The EV2639C-R-00A implements a complete hardware reference for the MP2639C QFN-26 IC, which integrates synchronous boost charging and reverse-buck discharging in a single controller. Its operation relies on external resistor programming of ILIM (432kΩ → 2.7A input limit), RISET (86.6kΩ → 2.5A charge current), and ROLIM (44.2kΩ → 5A discharge current limit).

It supports two distinct operating modes selected via the MODE pin: high for discharge (VBATT → VL), low for charge (VIN → VBATT). The board includes four LED drivers for voltage-based fuel gauge indication, ACOK status signaling, and CHG status feedback - all directly driven by MP2639C's dedicated output pins without external logic.

Key Specifications

Availability

EV2639C-R-00A is available at Aetrix Electronics and suitable for power-bank development, portable device sub-battery systems, and USB-C PD accessory validation requiring stable component supply and pre-validated MP2639C implementation.

Supply support for EV2639C-R-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, battery management, and motor control solutions.

The MP2639C product line targets portable dual-mode power systems, delivering integrated charge/discharge control, fuel-gauge interface, and safety monitoring in a single QFN package - designed specifically for space-constrained, USB-powered battery packs.

FAQ

How do I configure EV2639C-R-00A for charge mode?

Connect the MODE pin to ground (L) using jumper JP1 or external wire. Apply 5V input via USB or DC source to VIN. The board automatically initiates charging when battery voltage is below 8.4V, with CHG LED illuminated and ACOK LED active during valid input presence.

What triggers the discharge mode and how is it enabled?

Discharge mode activates when MODE is pulled high and the PB push button is pressed for <2.5 seconds. The board then powers VL (USB2 port) from the battery. Holding PB >2.5 seconds disables discharge. LED1–LED4 flash for 5 seconds to indicate battery voltage level.

Does EV2639C-R-00A support battery temperature monitoring?

Yes - it implements an NTC-based thermistor network using RNTC1 (10kΩ) and RNTC2 (15kΩ) to interface with the MP2639C's VNTC pin. This enables real-time battery temperature sensing and thermal foldback during charge or discharge cycles.

Can I adjust the input current limit, and how?

Yes - the input current limit is set by resistor RILIM on the ILIM pin. With RILIM = 432kΩ, the limit is 2.7A per the formula I_{IN_LIM} = 640 kΩ / R_ILIM. Replace RILIM to scale the limit; e.g., 79kΩ yields ~2.7A as specified in the quick-start guide.

What protections are implemented on this board?

The board implements input over-voltage protection (via VLIM circuit), battery over-voltage lockout (8.4V ±0.5%), thermal shutdown (MP2639C internal), charge timer timeout (prevents overcharging dead cells), and PB-button-controlled soft-start/stop - all verified in the schematic and BOM.

Is the 4-LED fuel gauge calibrated to specific voltage thresholds?

Yes - the LEDs are driven by MP2639C's LED1–LED4 outputs, each mapped to discrete battery voltage bands (e.g., LED1 only lit below 6.4V, all four lit above 8.0V). Thresholds are fixed in firmware and confirmed in the EV2639C-R-00A schematic's LED driver network.