Microchip Technology MCP73871T-1CAI/ML

Overview

MCP73871T-1CAI/ML from Microchip Technology is a fully integrated linear Li-Ion/Li-Polymer battery charge management IC with autonomous 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, ±0.5% voltage regulation at 4.20V, thermal regulation, and 20-pin QFN (4 mm × 4 mm) packaging - deployed in portable medical devices, GPS navigators, and Bluetooth headsets.

For engineers reviewing the MCP73871T-1CAI/ML datasheet, MCP73871T-1CAI/ML pinout, MCP73871T-1CAI/ML application, or MCP73871T-1CAI/ML equivalent, key selection criteria include VPCC-based input priority control, resistor-programmable 50 mA–1 A fast charge current, selectable 4.10/4.20/4.35/4.40 V charge voltage, integrated reverse discharge protection, and thermistor-based battery temperature monitoring across –40°C to +85°C.

Technical Context

The MCP73871T-1CAI/ML implements a constant-current/constant-voltage (CC/CV) charge algorithm with automatic preconditioning (0.1C trickle), programmable termination (7.5–12.5% of I_REG), and safety timer (4/6/8 hr options). Its Voltage Proportional Current Control (VPCC) dynamically reduces charge current when input voltage drops, preserving system load priority.

It integrates dual pass transistors (IN→OUT and VBAT→OUT) with 200 mΩ R_DS(on), ideal diode operation, and bidirectional power-path management. The device supports autonomous source selection between battery and input, with UVLO (V_START = V_REG + 0.15V typ), LBO (3.1 V threshold), and open-drain status outputs (STAT1/LBO, STAT2, PG) for LED or MCU interface.

Key Specifications

Pinout & Package

Package: 20-Lead QFN (4 mm × 4 mm), RoHS-compliant, with exposed thermal pad (EP) electrically connected to VSS. Requires PCB thermal pad connection for optimal 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 MCP73871T-1CAI/ML uniquely provides integrated power-path management with VPCC-based priority arbitration, making it the only option among the three capable of sustaining system operation during battery recharge from marginal sources like low-current USB hubs.

Availability

MCP73871T-1CAI/ML is available at Aetrix Electronics and suitable for GPS navigation devices, portable medical monitors, and Bluetooth headset charging cases requiring stable component supply, long-term lifecycle support, and industrial-temperature operation.

Supply support for MCP73871T-1CAI/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 Inc. is a leading provider of microcontrollers, analog devices, and battery management ICs, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The MCP73871 product line delivers highly integrated, thermally robust Li-ion charge controllers for portable electronics - designed specifically to eliminate discrete power-path components while ensuring USB compliance, battery safety, and seamless source handover.

FAQ

What is the exact charge voltage setting for MCP73871T-1CAI/ML?

The "C" in the suffix "1CAI" denotes the 4.20 V charge voltage option. This is factory-trimmed to ±0.5% tolerance at +25°C and ±0.75% over –5°C to +55°C, confirmed in DS20002090E Section 1.0 Electrical Characteristics. The MCP73871T-1CAI/ML does not support field adjustment - the voltage is fixed and verified per unit during production test.

How does MCP73871T-1CAI/ML handle power source switching between USB and AC-DC adapter?

The MCP73871T-1CAI/ML uses the SEL pin to configure input behavior: SEL = Low enables USB mode (100/500 mA limits per PROG2), while SEL = High activates AC-DC mode (up to 1.8 A total current). The device autonomously selects the active source based on voltage and UVLO status - no firmware or external logic is needed. MCP73871T-1CAI/ML maintains system power continuity during transitions via its dual-path architecture.

What does the "LBO" function on STAT1 mean for MCP73871T-1CAI/ML?

STAT1 serves dual function: charge status indicator (low during charging) and Low Battery Output (LBO) when VBAT > VIN. Per the "C" suffix, MCP73871T-1CAI/ML triggers LBO at 3.1 V (±0.15 V hysteresis), signaling the host that battery voltage has fallen below safe operating level. This occurs only when the system is running from battery - not during charging - and is electrically distinct from charge-complete status.

Can MCP73871T-1CAI/ML charge a deeply depleted Li-ion cell?

Yes. MCP73871T-1CAI/ML performs 0.1C preconditioning (trickle charge) when VBAT falls below 72% of VREG (e.g., <3.02 V for 4.20 V setting). This stage limits current to 7.5–12.5% of the programmed I_REG until VBAT rises above the threshold, preventing lithium plating and enabling safe recovery of cells down to ~2.5 V. This behavior is inherent to MCP73871T-1CAI/ML and requires no external configuration.

What thermal management features are built into MCP73871T-1CAI/ML?

MCP73871T-1CAI/ML incorporates three thermal protections: (1) junction-temperature-based charge current reduction starting near 125°C, (2) thermal shutdown at 150°C ±10°C with 10°C hysteresis, and (3) thermistor-based battery temperature monitoring via THERM pin using a 50 μA bias and factory-set 1.24 V / 0.25 V thresholds. All are active simultaneously and require no external components beyond a standard 10 kΩ NTC for battery sensing.