Monolithic Power Systems Inc. MP2635AGR-P

Overview

MP2635AGR-P from Monolithic Power Systems is a 2A synchronous switch-mode single-cell Li-ion/Li-polymer battery charger with integrated power path management and bidirectional boost OTG capability. It operates in charge mode (4.5–6V input), boost mode (2.5–4.35V battery to 4.2–6V SYS), and sleep mode, supporting USB-powered portable devices and power banks. Key confirmed parameters: 4.5–6V VIN range, 2A max programmable charge current, 0.5% accurate 3.6V/4.2V selectable battery voltage, 91% boost efficiency at 1A, and thermal regulation at 120°C.

For engineers reviewing the MP2635AGR-P datasheet, MP2635AGR-P pinout, MP2635AGR-P application, or MP2635AGR-P equivalent, this page delivers verified technical context on dual-mode operation, input-current-based power prioritization, NTC temperature monitoring, programmable charge/boost current limits, and fault recovery behavior - all critical for portable power system design and BOM validation.

Technical Context

The MP2635AGR-P implements a synchronous buck-boost architecture with independent control loops for input current (ILIM pin), battery charge current (ISET pin), SYS output voltage (FB pin), and junction temperature (thermal foldback at 120°C). Its mode selection logic uses PWIN voltage thresholds (0.75–0.85V low, 1.1–1.2V high) and VIN-to-BATT differential (>300mV) to autonomously transition between charge, boost, and sleep modes without external microcontroller intervention.

In charge mode, it executes three-phase charging (trickle → constant current → constant voltage) with auto-recharge triggered at 3.4V/3.96V (VB=ground/high), while boost mode uses OLIM-programmed current limiting and SYS over-voltage protection at 5.8–6.2V. The device integrates internal high-side PMOS (72mΩ) and low-side NMOS (70mΩ) switches, enabling up to 2A charge and 1A boost output with <120µs over-current blanking.

Key Specifications

Pinout & Package

MP2635AGR-P is housed in a thermally enhanced QFN24 package (4×4mm, 0.5mm pitch) with exposed PGND pad for optimal heat dissipation in portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-cell Li-ion charge + boost OTG applications.

Compared with BQ25895RTWR and IP5306, MP2635AGR-P uniquely balances autonomous power-path arbitration, comprehensive safety (NTC, timer, thermal foldback), and compact integration - making it optimal for standalone, safety-compliant portable designs without host processor dependency.

Availability

MP2635AGR-P is available at Aetrix Electronics and suitable for USB-C power banks, smartphone backup batteries, tablet docking stations, and IoT sensor hubs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2635AGR-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 MP2635AGR-P belongs to MPS's battery management IC product line, designed specifically for space-constrained portable electronics requiring integrated charge + boost functionality with robust safety and autonomous operation.

FAQ

What is the function of the VB pin on MP2635AGR-P?

The VB pin selects the battery full-charge voltage: connecting it to GND sets 3.6V for LiFePO₄ or low-voltage Li-ion cells, while leaving it floating or pulling it high configures 4.2V for standard Li-ion/Li-polymer. This selection directly determines the CV regulation point and affects termination accuracy (±0.5%) and auto-recharge thresholds (3.4V or 3.96V).

How does MP2635AGR-P manage power priority between system load and battery charging?

It uses the ILIM pin to set an input current limit; when system load demand exceeds this limit, the IC dynamically reduces charge current to maintain SYS voltage stability. This is implemented via a dedicated input-current control loop that overrides the charge-current loop, ensuring uninterrupted operation of connected peripherals during charging.

Can MP2635AGR-P operate without an external NTC thermistor?

Yes - the NTC pin is optional. If left unconnected, the NTC comparator is disabled and temperature-based charge suspension is inactive. However, for UL/IEC 62368-1 compliance in consumer products, NTC monitoring must be implemented using a compatible thermistor (e.g., NCP18XH103) and voltage-divider network per datasheet Figure 15.

What is the minimum recommended output capacitance on the SYS pin?

The datasheet specifies a minimum of 4.7µF ceramic capacitance from SYS to GND. This value ensures stable boost-mode regulation under transient loads up to 1A and suppresses output voltage ripple below 50mV peak-to-peak. Larger values (e.g., 10–22µF) further improve hold-up time during load steps but require careful layout to avoid resonance with parasitic inductance.

Does MP2635AGR-P support USB BC1.2 or proprietary fast-charge protocols?

No - it lacks protocol detection circuitry and relies on external logic or host MCU to identify adapter type. Its input operates within 4.5–6V, compatible with standard USB 2.0/3.0 ports and QC2.0 5V mode, but does not negotiate higher voltages or communicate with chargers using D+/D− signaling.

How is boost-mode over-current protection implemented?

When SYS current exceeds the OLIM-set limit, the IC enters constant-current regulation by reducing duty cycle. If the overload persists beyond 500ms (recovery time), it disables the boost converter and asserts BOOST pin low. Upon fault removal, it automatically resumes operation without requiring EN or MODE pin toggling.

What happens to the CHG and BOOST pins during sleep mode?

In sleep mode (VIN < 2V and MODE = low), both CHG and BOOST pins become high-impedance open-drain outputs. They neither sink nor source current, allowing external pull-up resistors to hold them high - providing unambiguous status indication that neither charge nor boost is active.