Monolithic Power Systems Inc. MP2635GR-Z

Overview

MP2635GR-Z from Monolithic Power Systems is a 2.0A switch-mode single-cell Li-ion/Li-Polymer battery charger with integrated power path management (PPM), supporting simultaneous system power delivery and battery charging. It operates in charge mode (4.5–6V input), boost mode (2.5–4.35V battery input → 4.2–5.6V SYS output), and sleep mode, with programmable 4.2V/3.6V full-charge voltage, ±0.5% CV accuracy, and 91% boost efficiency at 1A - used in portable power banks and sub-battery systems.

For engineers reviewing the MP2635GR-Z datasheet, MP2635GR-Z pinout, MP2635GR-Z application, or MP2635GR-Z equivalent, key selection considerations include input current limit programming via ILIM, battery full-voltage selection via VB, boost output current setting via OLIM, thermal regulation at 120°C, and dual-mode status indication via ACOK/CHG/BOOST pins.

Technical Context

The MP2635GR-Z implements synchronous buck-boost topology with bi-directional power path control: in charge mode, it regulates input current (up to 3A) and input voltage (via REG feedback) while delivering up to 2A CC/CV charge; in boost mode, it uses the same power stage to step up battery voltage to SYS with programmable 1.5A output current limit and short-circuit auto-recovery.

Its control architecture integrates five independent regulation loops - input current, input voltage, battery charge current, battery voltage, and junction temperature - with priority-based arbitration to ensure system power continuity during charging, while maintaining battery safety via OVP (103.3% × V_{BATT_FULL}), thermal shutdown (150°C), and NTC-based temperature monitoring.

Key Specifications

Pinout & Package

MP2635GR-Z is housed in a thermally enhanced QFN-24 package (4mm × 4mm, 0.5mm pitch) with exposed PGND pad for low-thermal-resistance PCB mounting (θ_JA = 42°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-cell switch-mode battery charger with power path management applications.

Compared with BQ25611DRTWR and IP2328TR, MP2635GR-Z uniquely combines 2A charging, 1.5A boost, input voltage regulation, and NTC support in one QFN-24 package - making it optimal for compact, safety-critical, dual-source portable devices requiring minimal external components.

Availability

MP2635GR-Z is available at Aetrix Electronics and suitable for portable power banks, USB peripheral hubs, smart wearable docks, and industrial handheld scanners requiring stable component supply across production lifecycles.

Supply support for MP2635GR-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 in the US, China, and Taiwan, and global manufacturing partnerships.

The MP2635 belongs to MPS's battery management IC product line, engineered specifically for space-constrained portable electronics needing integrated charge + boost functionality without compromising safety or efficiency.

FAQ

What is the function of the VB pin on MP2635GR-Z?

The VB pin selects the battery full-charge voltage: connecting VB to GND sets 3.6V for LiFePO₄ or low-voltage Li-ion, while leaving it floating or pulling it high selects 4.2V for standard Li-ion. This configuration is latched at power-up and determines both CV termination and recharge thresholds per the datasheet's electrical characteristics table.

How does MP2635GR-Z handle input current limiting during charging?

MP2635GR-Z uses the ILIM pin with an external resistor to set a precise input current limit (400–3000mA). When input current reaches this limit, the device reduces charge current to maintain regulated input voltage via the REG feedback loop - ensuring stable operation even with current-limited sources like USB 2.0 ports.

Can MP2635GR-Z operate without an external NTC thermistor?

Yes - the NTC pin is optional. If left unconnected, battery temperature monitoring is disabled, but all other functions (charging, boosting, protection) remain fully operational. However, for UL/IEC 62368-1 certification in consumer products, NTC integration is strongly recommended to meet thermal safety requirements.

What is the minimum battery voltage required to initiate boost mode?

Boost mode requires VBATT ≥ 2.9V to start (weak-battery threshold before boost begins). Once active, the device continues boosting down to 2.5V (weak-battery threshold during boost), at which point it disables output to prevent deep discharge and potential cell damage.

How is the boost output voltage programmed on MP2635GR-Z?

The boost output voltage is set by the external resistor divider from SYS to GND connected to the FB pin, with a 1.2V internal reference. The typical range is 4.2–5.6V; for 5V output, use R1 = 200kΩ and R2 = 51.1kΩ (per FB = 1.2V × (1 + R1/R2)). No internal register programming is required - entirely analog-configurable.

Does MP2635GR-Z support automatic transition between charge and boost modes?

Yes - the device monitors PWIN and MODE pins autonomously. When ACOK goes low (input lost) and MODE is high, it transitions from charge to boost mode within 1.2ms (per Figure 9). No MCU intervention is needed, enabling seamless power-source handoff in battery-backed systems.

What is the purpose of the TMR pin and how is it configured?

The TMR pin connects to an external capacitor (e.g., 0.1µF) to set total charge time (up to 6 hours) and trickle-charge timeout (60 minutes). If shorted to GND, the timer is disabled. This provides hardware-enforced charge duration limits - critical for safety certification and preventing prolonged charging of faulty batteries.