Monolithic Power Systems Inc. MP2678EG-104-LF-Z

Overview

MP2678EG-104-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, 10.4V input over-voltage protection (OVP), 4.35V battery OVP, 1.5A over-current protection (OCP), and thermal shutdown at 140°C. It functions as a redundant safety layer upstream of linear chargers in portable electronics, tolerating up to 30V input surges while maintaining regulated output during normal operation.

For engineers reviewing the MP2678EG-104-LF-Z datasheet, MP2678EG-104-LF-Z pinout, MP2678EG-104-LF-Z application, or MP2678EG-104-LF-Z equivalent, key selection considerations include its 10.4V OVP threshold, 5V regulated output with 330mV dropout at 1A, open-drain FLT fault indicator, active-low CE enable, and QFN-8 (2mm×2mm) package with exposed thermal pad.

Technical Context

The MP2678 operates as a high-side N-channel MOSFET-based linear regulator with integrated protection logic. Its functional block includes independent comparators for VIN OVP (10.4V threshold), VBATT OVP (4.35V threshold with 150mV hysteresis), and current-sense-based OCP (1.5A typ), each with dedicated blanking times (170–176µs) to reject transients.

Thermal monitoring uses on-die sensing with 140°C rising threshold and 120°C falling threshold for hysteresis, triggering FLT assertion and MOSFET turn-off. The CE pin provides active-low enable control with internal pull-down, and FLT is an open-drain output asserting low on any fault: input OVP, battery OVP, OCP, SCP, or thermal shutdown.

Key Specifications

Pinout & Package

MP2678EG-104-LF-Z is housed in a thermally enhanced QFN-8 package (2mm × 2mm, 0.5mm pitch) with exposed thermal pad connected to GND for optimal heat dissipation. Pin 2 (GND) and the exposed pad must be soldered to a solid ground plane per JEDEC MO-229 VCCD-3 standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2672AGQ-104-Z and BQ24314DSGT, MP2678EG-104-LF-Z uniquely integrates battery OVP, thermal shutdown, and soft-stop in a single QFN-8 package-reducing BOM count and eliminating reliance on external supervision circuits for critical safety functions.

Availability

MP2678EG-104-LF-Z is available at Aetrix Electronics and suitable for smartphone charging protection, USB-powered PDA power path, digital camera battery management, and portable medical monitor charger applications requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle support.

Supply support for MP2678EG-104-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 design centers across Asia and North America and global manufacturing partnerships.

The MP267x series targets portable Li-ion battery safety-designed specifically to add hardware-enforced protection layers upstream of linear chargers in space-constrained, high-reliability consumer and medical devices.

FAQ

What is the purpose of the VB pin, and how is it used in the circuit?

The VB pin is a high-impedance battery voltage sense input that connects via an external resistor divider to the positive terminal of the Li-ion cell. It enables the MP2678's proprietary battery OVP function by detecting when VBATT exceeds 4.35V (typical). The recommended RVB resistor range is 200kΩ to 1MΩ-smaller values improve fault-current limiting but increase OVP threshold error due to VB leakage current (≤100nA).

Does MP2678EG-104-LF-Z require external capacitors, and what are the recommended values?

Yes-CIN (input decoupling) and COUT (output filtering) are mandatory. CIN should be a 1µF to 4.7µF X5R/X7R ceramic capacitor placed close to VIN and GND to suppress hot-insertion overshoot. COUT is shared with the downstream charger and typically 1µF to 4.7µF; value depends on the charger's input requirements and ripple tolerance. Both must be rated for ≥10V DC.

How does the FLT pin behave during different fault conditions?

The FLT pin is an open-drain output that pulls low (≤0.2V at 5mA sink) during any of five fault events: input OVP, battery OVP, over-current, short-circuit at OUT, or thermal shutdown. It remains low until the fault clears and the internal recovery timer expires (e.g., 8ms after OVP removal, 50ms after OCP). When CE is high (disabled), FLT is actively pulled high.

What is the significance of the "-104" suffix in MP2678EG-104-LF-Z?

The "-104" denotes the input over-voltage protection threshold: 10.4V (typical). This is fixed by internal trimming and confirmed in the Ordering Information table. The MP2678EG variant is exclusively specified for 10.4V OVP-no other OVP options exist in this part number family.

Can MP2678EG-104-LF-Z operate without the CE pin connected?

Yes-the CE pin has an internal pull-down resistor, so leaving it unconnected defaults the device to enabled (ON) state. However, for deterministic power sequencing or system-level control, it is recommended to drive CE explicitly: ≤0.4V for ON, ≥1.5V for OFF. Floating CE may cause erratic behavior in noisy environments.

What thermal performance can be expected in a standard 4-layer PCB layout?

On a JEDEC-standard 4-layer PCB (2oz copper, 1in² GND plane under exposed pad), θJA is 80°C/W. At 1.5A load and 6V input, power dissipation is ~0.5W, resulting in ~40°C junction-to-ambient rise above ambient. With ambient at 85°C, junction temperature reaches ~125°C-within the 125°C max operating limit and well below the 140°C thermal shutdown threshold.

Is MP2678EG-104-LF-Z compatible with lithium-polymer batteries?

Yes-the device is explicitly qualified for both single-cell Li-ion and Li-polymer chemistries. Its 4.35V battery OVP threshold aligns with standard LiPo full-charge voltage, and its protection features (OVP, OCP, OTP) apply identically regardless of chemistry, as confirmed in the official description and Applications section.