Microchip Technology MCP73828-4.1VUA

Overview

MCP73828-4.1VUA from Microchip Technology is a linear single-cell lithium-ion battery charge management controller in an 8-pin MSOP package, featuring ±1% voltage regulation accuracy at 4.1 V, programmable fast-charge current via external sense resistor, automatic preconditioning for deeply depleted cells, and integrated temperature monitoring via THERM pin. It delivers stand-alone charging for space-constrained portable electronics with thermal safety and charge-complete signaling.

For engineers reviewing the MCP73828-4.1VUA datasheet, MCP73828-4.1VUA pinout, MCP73828-4.1VUA application, or MCP73828-4.1VUA equivalent, key selection criteria include its fixed 4.1 V regulation voltage (optimized for coke-anode Li-ion cells), open-drain CD10 charge-complete output, VDRV-driven external P-channel MOSFET control, and thermistor-based temperature qualification between 113 mV and 839 mV on the THERM pin.

Technical Context

The MCP73828-4.1VUA 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 amplifiers. Its architecture integrates dedicated comparators for THERM threshold detection (113 mV / 839 mV), CD10 charge-complete latching (10% I_PEAK threshold), and foldback current scaling.

It operates exclusively with an external P-channel MOSFET pass transistor driven by VDRV, using VSNS to monitor voltage drop across a series sense resistor (e.g., 100 mΩ for ~530 mA peak). Input supply range is strictly 4.5 V to 5.5 V; operation halts if VIN falls below VBAT, preventing battery discharge.

Key Specifications

Pinout & Package

Package: 8-pin MSOP (3.0 mm × 3.0 mm, 0.65 mm pitch), thermally enhanced for linear regulator applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP73828-4.1VUA, the -4.2VUA variant shifts termination voltage upward for different anode chemistries, while the BQ24040DRVR trades external component flexibility for integration and USB compliance - neither offers identical 4.1 V + discrete P-MOSFET + dual-threshold thermistor support.

Availability

MCP73828-4.1VUA is available at Aetrix Electronics and suitable for personal data assistants, cellular telephones, and hand held instruments requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for MCP73828-4.1VUA 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 manufacturer specializing in microcontrollers, analog devices, and power management ICs, with emphasis on reliability, longevity, and industrial-grade specifications.

The MCP73828 family was designed specifically for cost-sensitive, space-constrained single-cell Li-ion charging in portable consumer and industrial equipment - prioritizing accuracy, thermal safety, and stand-alone operation without host processor dependency.

FAQ

What is the exact voltage regulation setting for the MCP73828-4.1VUA?

The MCP73828-4.1VUA is factory-trimmed to regulate at 4.1 V with ±1% accuracy over –20°C to +85°C ambient temperature and full input voltage range (4.5 V to 5.5 V). This value is fixed and non-adjustable; it corresponds to the lower termination voltage recommended for lithium-ion cells with coke-based anodes. The MCP73828-4.1VUA achieves this via an internal 340.5 kΩ resistor in its voltage divider network, distinct from the 352.5 kΩ used in the 4.2 V variant.

Can the MCP73828-4.1VUA be used with a graphite-anode lithium-ion cell?

No - the MCP73828-4.1VUA is specifically intended for coke-anode lithium-ion cells rated for 4.1 V maximum charge voltage. Graphite-anode cells require 4.2 V termination; using MCP73828-4.1VUA with them results in chronic undercharging and reduced capacity. For graphite cells, Microchip's MCP73828-4.2VUA or compatible 4.2 V regulators must be selected instead. Always verify cell datasheet voltage specifications before selecting MCP73828-4.1VUA.

How does the THERM pin function on the MCP73828-4.1VUA?

The THERM pin on the MCP73828-4.1VUA sources a precise 25 µA current into an external NTC thermistor network. Charging is suspended if the resulting voltage falls below 113 mV (cold threshold) or exceeds 839 mV (hot threshold). These thresholds are factory-fixed and non-adjustable. A simple 10 kΩ resistor from THERM to GND disables monitoring. The MCP73828-4.1VUA does not digitize temperature - it performs analog window-comparison only.

What is the role of the CD10 pin on the MCP73828-4.1VUA?

The CD10 pin on the MCP73828-4.1VUA is an open-drain output that actively sinks current during charging (preconditioning, CC, and CV phases) and transitions to high-impedance when charge current drops to ≤10% of the programmed peak current - indicating charge completion. It can directly drive an LED with a series current-limiting resistor or interface to a microcontroller GPIO with an external pull-up. Maximum sink current is 30 mA; leakage in high-Z state is ≤1 µA.

Does the MCP73828-4.1VUA include an integrated power switch?

No - the MCP73828-4.1VUA is a controller-only IC and requires an external P-channel MOSFET (e.g., NDS8434 or IRF7404) connected to the VDRV and VSNS pins. VDRV provides gate drive, while VSNS senses the voltage drop across a series sense resistor to regulate charge current. This architecture allows thermal optimization of the pass element and supports higher current designs than fully integrated solutions, but adds two external components.