Monolithic Power Systems Inc. MP26028EQ-LF-P

Overview

MP26028EQ-LF-P from Monolithic Power Systems is a linear single-cell Li-ion battery charger IC with integrated 20V input surge tolerance, programmable 85mA–1A constant-current charging, 0.75% battery voltage regulation accuracy, and trickle-charge preconditioning for deeply discharged cells. It delivers charge status (CHG) and AC adapter power-good (ACOK) signals to host systems in portable electronics requiring compact, thermally robust charging solutions.

For engineers reviewing the MP26028EQ-LF-P datasheet, MP26028EQ-LF-P pinout, MP26028EQ-LF-P application, or MP26028EQ-LF-P equivalent, this device supports precise CV/CC charging control, programmable termination thresholds, thermal foldback protection, reverse current blocking (<1µA), and soft-start timing via external capacitor - critical for reliable USB/adapter-powered battery management in space-constrained designs.

Technical Context

The MP26028EQ-LF-P implements a linear charging architecture with proprietary constant-voltage auto-recharge and over-voltage protection that clamps at 4.25V with zero current output. Its CC/CV transition occurs at 4.2V ±21mV across –5°C to +75°C, and battery full detection is based on programmable current threshold (IBF) set between 10%–50% of ICHG.

Input surge protection operates up to 20V DC, while ACOK asserts low when VIN is within 2.5V–6.5V. The EN pin enables low-active operation, and VBIAS requires external resistor divider (500kΩ/100kΩ) to generate internal bias - enabling stable operation without external LDO.

Key Specifications

Pinout & Package

MP26028EQ-LF-P uses a 10-pin QFN package (3mm × 3mm, 0.5mm pitch) with exposed thermal pad connected to GND. Pin 1 is marked with dot; exposed pad must be soldered to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ24075RGTR and TP4056, MP26028EQ-LF-P provides superior input surge resilience (20V), fine-grained IBF/ICHG programming, and dual open-drain status outputs - making it optimal for adapter-aware portable systems requiring long-term reliability and JEITA-aligned charging behavior.

Availability

MP26028EQ-LF-P is available at Aetrix Electronics and suitable for smartphones, digital cameras, portable media players, and PDAs requiring stable component supply, RoHS-compliant packaging, and guaranteed -20°C to +85°C operating range.

Supply support for MP26028EQ-LF-P 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 in the US, China, and Taiwan, and global manufacturing partnerships.

The MP26028 belongs to MPS's battery management IC product line, engineered specifically for space-constrained, adapter-powered portable electronics needing robust linear charging with intelligent thermal response and system interface signaling.

FAQ

What input voltage range does MP26028EQ-LF-P support during normal operation?

The MP26028EQ-LF-P operates with nominal input voltage from 3.5V to 6.5V. It features built-in protection allowing survival of up to 20V DC transients, but sustained operation outside 3.5V–6.5V will disable charging - ACOK goes high only within 2.5V–6.5V, and the IC shuts down if VIN falls below 2.5V or exceeds 6.5V.

How is the charge termination current (IBF) programmed, and what is its valid range?

IBF is set by connecting a resistor RBF from the IBF pin to GND, where RBF = 1.7kΩ / IBF(A). Valid IBF values range from 10% to 50% of the programmed ICHG, corresponding to RBF values between 2×RCHG and 10×RCHG. For example, with ICHG = 500mA and RCHG = 3.3kΩ, RBF must be 6.6kΩ–33kΩ to yield IBF = 50–250mA.

Does MP26028EQ-LF-P support automatic recharge, and how is it triggered?

Yes - MP26028EQ-LF-P implements proprietary automatic recharge: when battery voltage drops ≥50mV below the trimmed 4.2V target (e.g., to ≤4.15V), the CV loop re-engages and resumes charging. This occurs without external intervention and maintains regulation accuracy within ±0.75%, ensuring consistent cell health across repeated discharge/charge cycles.

What is the function of the VBIAS pin, and why is an external resistor divider required?

VBIAS supplies internal bias voltage for analog circuits. It requires a 500kΩ resistor from IN to VBIAS and a 100kΩ resistor from VBIAS to GND to generate ~1V bias. This divider ensures stable operation across input voltage variations and eliminates need for external LDO - simplifying BOM while maintaining accuracy of VBATT regulation and current sensing.

Can MP26028EQ-LF-P be used with USB Type-C power sources?

Yes - MP26028EQ-LF-P accepts 5V USB power directly on the IN pin and complies with USB 2.0 voltage specifications. Its 20V surge tolerance protects against non-compliant chargers, and ACOK output confirms valid 5V presence. However, it does not negotiate USB PD protocols; it operates as a fixed-input linear charger, so PD voltage negotiation must occur upstream of the IN pin.

How does thermal protection operate, and does it halt charging completely?

No - MP26028EQ-LF-P uses proprietary thermal foldback: above 105°C, it modulates charge current into a sawtooth waveform instead of stopping. Average current decreases to limit die temperature, while maintaining partial charging functionality. Charging speed slows but continues, and full current resumes once junction temperature falls below 120°C (10°C hysteresis).

Is the exposed thermal pad electrically connected, and how must it be handled on the PCB?

Yes - the exposed pad is internally connected to GND and must be soldered to a dedicated PCB copper pour tied to the system ground plane. It serves both thermal dissipation (θJC = 12°C/W) and electrical grounding. Omitting this connection degrades thermal performance and may cause premature thermal shutdown or regulation inaccuracy.