Monolithic Power Systems Inc. MP2678EG-LF-Z

Overview

MP2678EG-LF-Z from Monolithic Power Systems is a single-cell Li-ion/Li-polymer battery charger protection IC with integrated 5V low-dropout linear regulation, input surge tolerance up to 30V, 10.4V input OVP threshold, and 4.35V proprietary battery OVP. It delivers up to 1.5A load current, features thermal shutdown at 140°C, and operates in handheld power paths where redundant overvoltage and overcurrent protection are required before the linear charger stage.

For engineers reviewing the MP2678EG-LF-Z datasheet, MP2678EG-LF-Z pinout, MP2678EG-LF-Z application, or MP2678EG-LF-Z equivalent, this device serves as a safety-critical front-end protector for USB-powered Li-ion charging systems-requiring precise OVP thresholds, fast fault response (<1µs OVP propagation), open-drain FLT signaling, and minimal external component count in space-constrained portable designs.

Technical Context

The MP2678EG-LF-Z functions as a high-voltage-tolerant, linear-mode pass element with an internal N-channel MOSFET bridging VIN and OUT. Its regulation loop maintains 5V ±0.4V output across 3.3V–10.4V input while monitoring VB for battery voltage via a resistor-divider interface and detecting faults using dedicated comparators for input OVP (10.4V typ), battery OVP (4.35V typ), OCP (1.5A typ), and OTP (140°C rising).

Fault handling is hardware-automated: upon any detected event (OVP, OCP, battery OVP, SCP, or thermal shutdown), the internal MOSFET turns off within 1µs (OVP) or 176µs (battery OVP), pulling FLT low. Recovery requires removal of the fault condition plus fixed timing windows-8ms for POR/OVP, 50ms for OCP-and thermal hysteresis (140°C trip / 120°C release).

Key Specifications

Pinout & Package

The MP2678EG-LF-Z is housed in a thermally enhanced QFN-8 package (2mm × 2mm, 0.5mm pitch) with exposed thermal pad. The pad must be soldered to a GND plane for optimal thermal performance and electrical stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Li-ion charger protection applications.

Compared with MP2672GQ-Z and TI's BQ296xxx, the MP2678EG-LF-Z uniquely integrates input surge tolerance, 5V LDO regulation, and battery OVP in one QFN-8 device-reducing board area by ~40% and eliminating inter-stage coupling risks in compact USB-charged systems.

Availability

MP2678EG-LF-Z is available at Aetrix Electronics and suitable for smartphone charging protection, digital camera power path management, Bluetooth headset battery management, and portable medical monitor applications requiring stable component supply, RoHS-compliant packaging, and guaranteed long-term lifecycle support.

Supply support for MP2678EG-LF-Z 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 converters, battery management, and motor drivers.

The MP2678 belongs to MPS's battery protection IC product line, designed specifically to add robust, integrated safety layers for Li-ion charging systems in consumer and portable medical electronics-prioritizing small footprint, low thermal resistance, and deterministic fault response.

FAQ

What is the purpose of the VB pin, and how should it be connected?

The VB pin monitors battery voltage for proprietary battery OVP detection. It must be connected to the battery pack's positive terminal through an isolation resistor (200kΩ–1MΩ) to limit fault current if the IC fails. Typical leakage is 100nA; higher resistor values increase OVP threshold error (e.g., +20mV at 1MΩ), so 200kΩ–470kΩ is recommended for <5mV error.

Does the MP2678EG-LF-Z require external compensation components?

No. The MP2678EG-LF-Z uses an internally compensated regulation loop and requires no external capacitors or resistors for stability. Only standard decoupling capacitors (CIN = 1–4.7µF ceramic, COUT = 1–4.7µF ceramic) and the VB/RFLT resistors are needed-no feedback network or frequency compensation is required.

How does the FLT pin behave during different fault conditions?

The FLT pin is an open-drain output pulled low during input OVP, battery OVP, overcurrent, short-circuit, or thermal shutdown. It remains low until the fault clears and recovery timing completes (e.g., 8ms after OVP removal). When CE is high (disabled), FLT is pulled high-providing distinct enable/fault states for system diagnostics.

Can the MP2678EG-LF-Z operate with input voltages below 3.3V?

No. The absolute minimum operating VIN is 3.3V per the Recommended Operating Conditions table. Below this, the internal POR circuit holds the device in reset (VOUT disabled), and the 2.8V POR threshold ensures reliable startup only when sufficient input energy is present for stable 5V regulation.

What is the thermal performance of the QFN-8 (2mm×2mm) package?

The QFN-8 package has θJA = 80°C/W and θJC = 60°C/W on a 4-layer PCB per JESD51-7. With 1.5A load and 300mV dropout, power dissipation is ~450mW; junction temperature rise is ~36°C above ambient-well below the 125°C max operating TJ, provided the exposed pad is soldered to a solid GND plane.

Is the MP2678EG-LF-Z compatible with USB-C PD sources?

Yes-its 30V surge tolerance and 10.4V input OVP allow safe operation with USB-C PD adapters delivering 5V, 9V, or 15V, provided the input is clamped or filtered before VIN. However, it does not negotiate PD contracts; it acts solely as a post-regulator and protector for fixed 5V output stages.