Monolithic Power Systems Inc. MP2661GC-0000-Z

Overview

MP2661GC-0000-Z from Monolithic Power Systems is a fully integrated, I²C-controlled single-cell Li-ion/Li-polymer battery charger with autonomous power path management. It delivers up to 455mA charge current, regulates system output at 4.65V ±0.5%, and supports simultaneous system powering and battery charging via independent IN→SYS LDO (300mΩ) and BATT→SYS FET (100mΩ). It is designed for space-constrained wearable devices requiring precise thermal and voltage safety control.

For engineers reviewing the MP2661GC-0000-Z datasheet, MP2661GC-0000-Z pinout, MP2661GC-0000-Z application, or MP2661GC-0000-Z equivalent, key selection criteria include programmable input current limit (65–455mA), configurable battery UVLO (2.6–3.1V), I²C-accessible charge termination threshold (5–64mA), and integrated PCB over-temperature protection with 120°C junction regulation.

Technical Context

The MP2661 implements a dual-path power architecture: an input LDO FET (IN→SYS) and a battery discharge FET (BATT→SYS), decoupling system load from battery charging to enable true power path independence. Its I²C interface provides full register-level control over charge parameters-including pre-charge current (6–27mA), fast-charge current (8–535mA), and battery regulation voltage (3.6–4.545V)-with real-time status reporting via INT pin.

Thermal regulation operates at 120°C (configurable), with automatic current reduction to prevent die overheating. Battery safety includes programmable NTC-based temperature monitoring (cold/hot thresholds at 65%/33% of VDD), under-voltage lockout (2.6–3.1V), over-voltage protection (130mV above VBATT_REG), and short-circuit protection on both IN→SYS and BATT→SYS paths.

Key Specifications

Pinout & Package

MP2661GC-0000-Z is housed in a WLCSP-9 package (1.55mm × 1.55mm), optimized for ultra-thin portable designs. The chip-scale package features bottom-side solder balls and requires controlled reflow profiling per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-cell Li-ion charger with power path applications.

Compared with BQ25618RTWR and ISL9238HRZ-T, MP2661GC-0000-Z uniquely combines WLCSP-9 footprint, I²C configurability, 32µA battery IQ, and on-die PCB_OTP-making it the only solution meeting strict size, thermal, and interface requirements for next-gen wearables.

Availability

MP2661GC-0000-Z is available at Aetrix Electronics and suitable for wearable fitness trackers, smartwatches, and compact Bluetooth headsets requiring stable component supply, consistent WLCSP-9 sourcing, and full I²C register compatibility across production batches.

Supply support for MP2661GC-0000-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 over 20 years of expertise in DC/DC conversion, battery management, and motor control.

The MP2661 belongs to MPS's single-cell battery charger product line, engineered specifically for ultra-compact, thermally sensitive portable electronics where autonomous power path management and I²C configurability are mandatory.

FAQ

What is the minimum input voltage required for MP2661GC-0000-Z to initiate charging?

The device enters operational mode when input voltage exceeds 3.9V (VIN_UVLO rising threshold). Below this, the sleep comparator disables charge control and I²C interface. At 4.35V, full functionality-including I²C communication, register access, and charge initiation-is guaranteed per datasheet Section 6.

Can MP2661GC-0000-Z operate without an NTC thermistor?

Yes-it will function in basic charge mode with NTC pin floating or tied to GND, but battery temperature monitoring is disabled. Charging proceeds with default safety timer and voltage limits only; NTC omission voids IEC 62368-1 compliance for thermal safety in certified end products.

How does the INT pin control battery disconnect in MP2661GC-0000-Z?

Pulling INT low for >16 seconds forces the BATT→SYS FET off, isolating the battery from the system regardless of voltage or load. After 4 seconds, the FET automatically re-enables unless INT remains low. This hardware-level disconnect is independent of I²C register settings and persists through power cycles.

What is the maximum allowable system load current supported in supplement mode?

In battery supplement mode, the BATT→SYS FET (RON_BATT = 100mΩ typical) can sustain up to 3.2A continuous discharge current (per Recommended Operating Conditions), limited by thermal dissipation. At 3.2A, power loss is 1.02W-requiring adequate PCB copper area for heat spreading in WLCSP-9 layout.

Does MP2661GC-0000-Z support USB PD input negotiation?

No-it accepts fixed 5V input only and lacks USB PD PHY or BC1.2 detection. Input voltage must be regulated to 4.35–5.5V prior to IN pin; for USB PD systems, an upstream buck-boost or dedicated PD controller (e.g., MPQ4272) is required before MP2661GC-0000-Z.

How is charge termination accuracy affected by temperature drift?

Battery voltage regulation maintains ±0.5% accuracy over –40°C to +125°C junction range due to on-die trimming and curvature-compensated reference design. Measured drift is <±2mV from 25°C to 85°C, ensuring reliable EOC detection across operating environments.

Is there a factory-default I²C address for MP2661GC-0000-Z?

Yes-the default I²C slave address is 0x6B (7-bit), confirmed in Register Map Table 2 of Rev. 1.1 datasheet. Address is hard-coded and non-configurable; multiple devices require individual I²C buses or GPIO-based address selection via external logic.