Microchip Technology MCP73871-2AAI/ML

Overview

MCP73871-2AAI/ML from Microchip Technology is a fully integrated linear Li-Ion/Li-Polymer battery charge management IC with system load sharing, supporting simultaneous system power delivery and battery charging from USB or AC-DC sources. It delivers up to 1.8A total input current, features ±0.5% voltage regulation at 4.20V, resistor-programmable fast charge current (50 mA to 1A), and operates across –40°C to +85°C. It is used in portable medical devices and Bluetooth headsets requiring autonomous power-path control.

For engineers reviewing the MCP73871-2AAI/ML datasheet, MCP73871-2AAI/ML pinout, MCP73871-2AAI/ML application, or MCP73871-2AAI/ML equivalent, key selection criteria include its VPCC-based input voltage proportional current control, dual-source input selection (SEL pin), thermal regulation with 150°C shutdown, open-drain status outputs (STAT1/LBO, STAT2, PG), and 20-lead QFN package with exposed thermal pad.

Technical Context

The MCP73871-2AAI/ML implements a constant-current/constant-voltage (CC/CV) charge algorithm with selectable termination via PROG3, preconditioning for deeply depleted cells (0.1C), and automatic recharge triggered at VREG – 0.15V. Its Voltage Proportional Charge Control (VPCC) dynamically reduces charge current when input voltage drops below 1.23V threshold, preserving system load priority.

It integrates dual pass transistors (IN→OUT and VBAT→OUT) with 200 mΩ R_DS(on), ideal diode operation, reverse discharge protection, and thermistor-based temperature monitoring using a 50 μA bias current on THERM. The device supports USB-compliant current limits (100/500 mA) and AC-DC adapter mode (up to 1.65A typical shared current).

Key Specifications

Pinout & Package

Package: 20-lead QFN (4 mm × 4 mm) with exposed thermal pad (EP), internally connected to VSS. Requires PCB thermal pad connection to ground plane for thermal performance (θ_JA = 50°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Li-Ion charge management applications.

Compared with BQ24075RGTR and MCP73831T-2DCI/OT, the MCP73871-2AAI/ML uniquely supports adaptive load sharing via VPCC, dual-source selection (USB/AC-DC), and integrated LBO-making it optimal for portable systems requiring robust power arbitration and user battery-status awareness.

Availability

MCP73871-2AAI/ML is available at Aetrix Electronics and suitable for portable medical devices, Bluetooth headsets, GPS navigators, and digital cameras requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MCP73871-2AAI/ML 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

Microchip Technology is a leading provider of microcontrollers, analog components, and battery management solutions, serving industrial, automotive, and consumer markets with high-reliability silicon and design tools.

The MCP73871 product line delivers integrated linear charge management with system load sharing for space-constrained portable electronics, targeting applications where USB and wall-adapter dual-source operation and autonomous power-path control are essential.

FAQ

What is the exact charge voltage setting for MCP73871-2AAI/ML?

The MCP73871-2AAI/ML is factory-configured for 4.20V constant-voltage regulation with ±0.5% tolerance at +25°C. This value is fixed per the '2' in the part number and applies across the full operating temperature range of –40°C to +85°C. The device does not support runtime switching between 4.10V/4.20V/4.35V/4.40V options - only hardware variants differ in this parameter.

How does the VPCC function work on MCP73871-2AAI/ML?

The VPCC pin on MCP73871-2AAI/ML enables voltage-proportional charge current control: when the voltage applied to VPCC falls below 1.23V (±3%), the IC automatically reduces charge current to preserve system load voltage. It is typically driven by a resistor divider from IN. This ensures the OUT rail stays stable even when input source impedance causes VIN sag - a core differentiator versus basic chargers.

What does the '2AAI/ML' suffix indicate for MCP73871-2AAI/ML?

The '2' denotes 4.20V charge voltage; first 'A' indicates LBO disabled (but MCP73871-2AAI/ML actually implements LBO at 3.0V per DS20002090E page 19 footnote); second 'A' means 4-hour safety timer; 'I' specifies industrial temperature grade (–40°C to +85°C); '/ML' identifies the 20-lead 4×4 mm QFN package with exposed thermal pad.

Can MCP73871-2AAI/ML operate without a battery connected?

Yes - MCP73871-2AAI/ML can power the system load directly from IN to OUT even with no battery attached. In this mode, PG goes low (indicating valid input), STAT1 and STAT2 remain high-impedance, and the device behaves as a low-loss power-path switch with ideal diode operation. Reverse discharge protection remains active to prevent backfeed into the input source.

What thermal management provisions does MCP73871-2AAI/ML include?

MCP73871-2AAI/ML incorporates three thermal protections: (1) junction temperature-dependent charge current reduction (thermal regulation), (2) hard thermal shutdown at 150°C (±5°C) with 10°C hysteresis, and (3) mandatory PCB thermal pad (EP) connection to VSS for θ_JA = 50°C/W dissipation. These ensure reliability in sealed enclosures or high-ambient environments without external thermal sensors.