Monolithic Power Systems Inc. MP2605DQ-LF-P

Overview

MP2605DQ-LF-P from Monolithic Power Systems is a linear single-cell Li-Ion/Li-Polymer battery charger IC with integrated 28V input surge protection, programmable 200mA–1A constant-current charging, trickle charge mode for deeply discharged batteries (<2.6V), thermal foldback at ≥120°C, and NTC-based temperature monitoring (0°C to 50°C). It delivers precise 4.20V ±20mV CV regulation and supports USB/AC adapter input (3.5V–6.5V) in portable power management systems.

For engineers reviewing the MP2605DQ-LF-P datasheet, MP2605DQ-LF-P pinout, MP2605DQ-LF-P application, or MP2605DQ-LF-P equivalent, this device is selected for compact, thermally constrained battery-powered designs requiring robust overvoltage tolerance, accurate end-of-charge detection (20% I_CHG), auto-recharge at 4.0V, and fault signaling via open-drain CHG/ACOK pins.

Technical Context

The MP2605 operates in three sequential charge phases: trickle (10% I_CHG until V_BATT ≥2.6V), constant-current (programmed via external R_CHG on ISET pin), and constant-voltage (4.20V regulation with current tapering to 20% I_CHG). Internal oscillator on TMR pin sets timer cycles (32768 for trickle timeout, 262144 for total charge limit) using external capacitor.

It integrates dual overvoltage protection: 7V input OVP with 400mV hysteresis and 8.2V clamp on ACOK/CHG pins; thermal regulation reduces average charge current above 120°C; NTC comparator monitors R_NTC window (32.3kΩ–376.6kΩ) corresponding to 0°C–50°C for TH11-4H104F thermistor.

Key Specifications

Pinout & Package

MP2605DQ-LF-P is housed in a thermally enhanced 10-pin 3mm × 3mm QFN package with exposed thermal pad (pin 5), optimized for PCB heat dissipation in space-constrained portable designs.

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, MP2605DQ-LF-P uniquely combines 28V surge resilience, autonomous NTC window validation, and dual-stage hardware timers-reducing system-level safety validation effort and eliminating external protection components.

Availability

MP2605DQ-LF-P is available at Aetrix Electronics and suitable for smartphones, digital cameras, portable medical devices, and Bluetooth headsets requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2605DQ-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 mixed-signal ICs for power management, motor drive, and automotive applications.

The MP2605 belongs to MPS's battery management IC product line, engineered for space-constrained portable electronics needing robust, integrated, and safety-certifiable charging solutions without external protection circuitry.

FAQ

What is the maximum allowable input voltage for continuous operation?

The MP2605DQ-LF-P operates continuously within 3.5V to 6.5V input range. Its proprietary surge protection tolerates transient inputs up to +28V without damage, but sustained voltage above 7.0V triggers input OVP shutdown. The ACOK pin asserts low only when VIN is between 3.0V and 7.0V, confirming valid adapter presence.

How is charge current programmed, and what resistor yields 800mA?

Charge current is set by connecting a resistor (R_CHG) from ISET (pin 8) to GND. Using the formula I_CHG = 1700 / R_CHG (mA/kΩ), an 800mA setting requires R_CHG = 2.125kΩ. The datasheet recommends 2.05kΩ (800mA typical) with 2.3kΩ–11kΩ as the optimal range for stability and accuracy.

Does the MP2605 support automatic recharge, and at what voltage does it trigger?

Yes, MP2605DQ-LF-P supports automatic recharge. After full-charge termination, it monitors battery voltage and reinitiates the full CC/CV cycle when V_BATT drops to 4.0V (with 100mV hysteresis). This behavior is fully hardware-based and requires no host MCU intervention or configuration.

What happens if the NTC thermistor is disconnected or out-of-range?

If the NTC pin senses resistance below 32.3kΩ (indicating <0°C) or above 376.6kΩ (indicating >50°C), the MP2605 immediately halts charging and holds CHG pin in toggle mode. Charging resumes only after NTC resistance returns to the valid window and SHDN is cycled or VIN is recycled.

Can the internal timer be disabled, and how?

Yes, the internal timer can be disabled by shorting the TMR pin (pin 4) to GND. This action disables both trickle-charge timeout (32768 cycles) and total charge timeout (262144 cycles), allowing indefinite CV-mode charging-use only in controlled lab environments where battery health monitoring is externally managed.

What is the thermal protection behavior, and at what junction temperature does it activate?

Thermal protection activates at 120°C (typical) junction temperature, progressively reducing average charge current to limit die temperature rise. It does not shut down the IC entirely but enters foldback mode to sustain safe operation. Recovery occurs automatically once TJ falls below 105°C hysteresis threshold.

Is there reverse current protection from battery to input when the adapter is unplugged?

Yes-when SHDN is high (disabled) and VIN is floating or 0V, reverse current from BATT to VIN is limited to <1µA. This ultra-low leakage preserves battery charge during storage or transport, critical for devices shipped with partial charge.