Microchip Technology MCP73827-4.2VUA

Overview

MCP73827-4.2VUA from Microchip Technology is a single-cell lithium-ion linear charge management controller in an 8-pin MSOP package, featuring 4.2 V ±1% regulated output voltage, programmable fast-charge current via external sense resistor, automatic preconditioning for deeply depleted cells, and open-drain MODE status output. It operates from 4.5 V to 5.5 V input and supports industrial temperature range (–20°C to +85°C), targeting compact portable chargers with minimal external components.

For engineers reviewing the MCP73827-4.2VUA datasheet, MCP73827-4.2VUA pinout, MCP73827-4.2VUA application, or MCP73827-4.2VUA equivalent, key selection considerations include its fixed 4.2 V regulation for graphite-anode Li-ion cells, VDRV-driven external P-channel MOSFET control, IMON current monitor output for microcontroller-based charge termination, and thermal-aware linear architecture requiring careful PCB layout and pass transistor selection.

Technical Context

The MCP73827-4.2VUA implements a three-phase charge algorithm-preconditioning (foldback current at ~43% of peak), controlled-current fast charge, and constant-voltage regulation-with internal voltage reference (1.2 V) and precision feedback loop. Its analog core includes dedicated amplifiers for voltage regulation (±1% over –20°C to +85°C), current sensing (100 dB gain), and foldback current scaling (K = 0.43).

Digital logic manages SHDN-initiated enable/disable, MODE open-drain state transitions (low during preconditioning/fast charge, high-Z in CV mode), and automatic power-down when VIN < VBAT. The device requires no external clock or programming and interfaces directly to a host MCU via IMON (26 V/V gain) and MODE, while driving an external P-MOSFET through VDRV with 0.08 mA sink/1 mA source capability.

Key Specifications

Pinout & Package

Package: 8-pin MSOP (UA), 3.0 mm × 4.9 mm footprint, 0.65 mm pitch, molded thickness 0.75–0.95 mm, thermal resistance θJA = 206°C/W on single-layer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP73827-4.2VUA, MCP73831T-420I/OT trades external FET flexibility and IMON monitoring for smaller size and simpler layout, while BQ24075RGTR adds programmability and safety at the cost of MCU dependency and larger footprint.

Availability

MCP73827-4.2VUA is available at Aetrix Electronics and suitable for personal data assistants, cellular telephones, and hand-held instruments requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MCP73827-4.2VUA 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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and power management ICs, with emphasis on reliability, longevity, and broad ecosystem support.

The MCP73827 product line delivers cost-optimized, stand-alone linear charge controllers for space-limited consumer and industrial Li-ion applications, prioritizing simplicity, thermal predictability, and minimal external component count.

FAQ

What is the exact regulated output voltage of the MCP73827-4.2VUA?

The MCP73827-4.2VUA provides a fixed 4.2 V regulation voltage with ±1% accuracy over the full operating temperature range (–20°C to +85°C) and input supply range (4.5 V to 5.5 V). This value is factory-trimmed and applies specifically to the MCP73827-4.2VUA variant, distinguishing it from the 4.1 V version (MCP73827-4.1VUA).

How does the MCP73827-4.2VUA handle deeply discharged lithium-ion cells?

The MCP73827-4.2VUA initiates automatic preconditioning when the battery voltage falls below ~2.4 V, applying a foldback current scaled to approximately 43% of the programmed peak fast-charge current. This gentle recovery phase minimizes heat dissipation in the external P-MOSFET and protects cell integrity before entering controlled-current charging. The MCP73827-4.2VUA performs this function autonomously without external intervention.

Can the MCP73827-4.2VUA operate without a microcontroller?

Yes, the MCP73827-4.2VUA is designed for stand-alone operation: it executes the full CC/CV charge algorithm autonomously, uses the MODE pin to drive an LED for visual status, and terminates charge based on timer or IMON threshold detection. While IMON and MODE support MCU integration, the MCP73827-4.2VUA requires no firmware or digital interface to function as a complete charger.

What external components are mandatory for basic operation of the MCP73827-4.2VUA?

Four components are mandatory: (1) an external P-channel MOSFET driven by VDRV, (2) a precision current-sense resistor (RSENSE) between VIN and the MOSFET source, (3) ≥10 µF capacitor from VBAT to GND for loop stability, and (4) ≥10 µF capacitor from VIN to GND. The SHDN pin may be tied to VIN for automatic enable; no other passive or active components are required for core charging functionality of the MCP73827-4.2VUA.

What is the purpose and electrical behavior of the IMON pin on the MCP73827-4.2VUA?

The IMON pin on the MCP73827-4.2VUA delivers a voltage output with 26 V/V gain proportional to the voltage drop across the external sense resistor (VIN − VSNS), directly representing charge current magnitude. It enables precise, ratiometric current monitoring using a host MCU's ADC without additional signal conditioning. The MCP73827-4.2VUA specifies IMON output accuracy and linearity across temperature, making it suitable for adaptive charge termination and battery diagnostics.