Microchip Technology MCP73831-5ACI/MC

Overview

MCP73831-5ACI/MC from Microchip Technology is a fully integrated linear lithium-ion/polymer battery charge management controller in an 8-lead 2 mm × 3 mm DFN package with exposed thermal pad. It delivers 4.50 V ±0.75% constant-voltage regulation, programmable fast-charge current up to 500 mA (via external PROG resistor), and tri-state STAT output for status indication. It is designed for USB-powered portable devices requiring compact, low-component-count charging solutions.

For engineers reviewing the MCP73831-5ACI/MC datasheet, MCP73831-5ACI/MC pinout, MCP73831-5ACI/MC application, or MCP73831-5ACI/MC equivalent, key selection criteria include its factory-set 4.50 V regulation voltage, thermal regulation capability, preconditioning and termination ratio options, and compatibility with single-cell Li-ion/Li-polymer batteries in space-constrained designs.

Technical Context

The MCP73831-5ACI/MC implements a constant-current/constant-voltage (CC/CV) charge algorithm with factory-configured 4.50 V regulation, 10%/20%/40% or disable preconditioning, and 5%/7.5%/10%/20% end-of-charge termination thresholds. Its internal P-channel MOSFET pass transistor features 350 mΩ typical R_DS(ON) at 105°C and integrates reverse discharge protection.

It employs undervoltage lockout (UVLO) with 3.45 V start threshold and 70 mV hysteresis, automatic power-down when V_DD < (V_BAT + 50 mV), and thermal regulation that reduces charge current above ~105°C to prevent die overheating-critical for sustained high-current operation in sealed enclosures.

Key Specifications

Pinout & Package

Package: 8-Lead, 2 mm × 3 mm DFN with exposed thermal pad (EP), EP internally connected to VSS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP73831-2ACI/MC, the MCP73831-5ACI/MC delivers higher energy density via 4.50 V termination, while BQ24075RGTR adds configurability and power-path control at the cost of MCU dependency and larger footprint-making MCP73831-5ACI/MC optimal for cost-sensitive, MCU-less, high-density portable designs.

Availability

MCP73831-5ACI/MC is available at Aetrix Electronics and suitable for USB chargers, wearable health monitors, industrial handheld scanners, and smart home sensors requiring stable component supply and long-term production continuity.

Supply support for MCP73831-5ACI/MC 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 Flash-IP solutions, serving automotive, industrial, communications, and consumer markets with high-reliability silicon and development tools.

The MCP73831/2 product line was engineered for space-constrained, cost-sensitive portable electronics needing fully integrated, single-cell Li-ion/Li-polymer charging with minimal external components and robust thermal management.

FAQ

What is the exact regulation voltage of the MCP73831-5ACI/MC?

The MCP73831-5ACI/MC has a factory-set constant-voltage regulation point of 4.50 V with a tolerance of ±0.75%, meaning it maintains battery voltage between 4.466 V and 4.534 V during the constant-voltage phase. This value is laser-trimmed and fixed per the "5" suffix in the part number, and cannot be adjusted externally. The MCP73831-5ACI/MC achieves this accuracy across −40°C to +85°C ambient temperature.

How does the MCP73831-5ACI/MC handle thermal regulation, and what is its impact on charge time?

The MCP73831-5ACI/MC continuously monitors die temperature and begins folding back charge current when junction temperature exceeds ~105°C, preventing thermal shutdown. This allows sustained charging under high ambient or high-input-voltage conditions. For example, with R_PROG = 2 kΩ (500 mA nominal) and V_DD = 5.5 V, thermal regulation activates at ~115°C, reducing current to ~400 mA-extending full-charge time by ~12% but ensuring reliability and eliminating restart delays caused by hard shutdown.

Can the MCP73831-5ACI/MC be used without a microcontroller, and how is charge status indicated?

Yes, the MCP73831-5ACI/MC operates fully autonomously without any microcontroller. Its tri-state STAT output provides real-time charge state: low during preconditioning, fast-charge, and constant-voltage modes; high during charge-complete standby; and high-impedance during shutdown or no-battery conditions. This allows direct LED drive (with current-limiting resistor) or GPIO monitoring-enabling simple, low-cost status feedback in standalone applications.

What is the role of the exposed thermal pad (EP) on the MCP73831-5ACI/MC, and how must it be connected?

The exposed thermal pad (EP) on the MCP73831-5ACI/MC is internally bonded to VSS and serves as the primary thermal conduction path to the PCB. It must be soldered to a solid copper pour tied to the system ground plane, with ≥4 thermal vias (0.3 mm diameter) connecting to inner or back-side ground layers. Failure to connect EP results in θ_JA degrading from 76°C/W to >120°C/W, severely limiting usable charge current and triggering premature thermal regulation.

How does the MCP73831-5ACI/MC detect absence of a battery, and what design considerations apply?

The MCP73831-5ACI/MC sources 6 µA from the VBAT pin; if VBAT rises to V_REG + 100 mV (≈4.60 V), it declares "no battery." To ensure reliable detection, the impedance seen at VBAT before battery insertion must exceed 7 MΩ-achieved by avoiding pull-down resistors or capacitive loads on the battery node. This prevents false "no battery" assertions and enables safe reverse-discharge blocking (<2 µA) during storage.