Microchip Technology MCP73838T-FCI/UN

Overview

MCP73838T-FCI/UN from Microchip Technology is a fully integrated linear Li-Ion/Li-Polymer battery charge management controller with autonomous AC adapter or USB port source selection, ±0.5% voltage regulation accuracy, 4.20V fixed charge voltage, 1000 mA max AC charge current, and Timer Enable (TE) pin for safety timer control - used in ultra-mobile devices requiring dual-source charging and thermal-safe operation.

For engineers reviewing the MCP73838T-FCI/UN datasheet, MCP73838T-FCI/UN pinout, MCP73838T-FCI/UN application, or MCP73838T-FCI/UN equivalent, this page delivers verified technical context, real-world design meanings for key specs, validated DFN-10 pin functions, confirmed alternatives with functional differences, and supply-chain-ready availability details - all grounded in Microchip's DS20002071C specification.

Technical Context

The MCP73838T-FCI/UN implements a CC/CV charge algorithm with factory-set 4.20V regulation, selectable preconditioning (10% I_REG), and programmable termination (5% I_REG). Its autonomous power source selector prioritizes VAC over VUSB and enforces USB 100/500 mA compliance via PROG2 logic level.

Thermal regulation limits charge current above 150°C die temperature, while the TE pin (pin 8) enables/disables the safety timer (4/6/8 hr options). The device integrates pass FETs (350 mΩ R_DS(on)), reverse discharge protection, and 50 µA thermistor bias for NTC monitoring - all operating across –40°C to +85°C ambient.

Key Specifications

Pinout & Package

Package: 10-Lead 3 mm × 3 mm DFN with exposed thermal pad (EP), internally connected to VSS. Requires soldering EP to PCB ground plane for optimal thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP73837T-FCI/UN, MCP73838T-FCI/UN trades power-good reporting for hardware-enforced charge timeout - critical for unattended charging. Versus BQ24075RGTR, it eliminates external switching logic but caps at 1A, simplifying layout at the cost of peak current headroom.

Availability

MCP73838T-FCI/UN is available at Aetrix Electronics and suitable for smartphones, portable media players, ultra-mobile devices, and digital cameras requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MCP73838T-FCI/UN 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 manufacturing and support infrastructure.

The MCP7383x family was designed specifically for space-constrained, dual-input Li-ion charging in portable consumer electronics - emphasizing integration, thermal robustness, and USB/AC compliance without host dependency.

FAQ

What is the exact charge voltage regulation setting for MCP73838T-FCI/UN?

The MCP73838T-FCI/UN is factory-configured for 4.20 V ±0.5% constant-voltage regulation, as specified in Microchip's DS20002071C datasheet Section 1.0. This value is fixed and not user-adjustable - it matches the standard termination voltage for most single-cell Li-ion batteries and ensures safe, full capacity charging without overvoltage stress on the cell.

Does MCP73838T-FCI/UN support both USB and AC adapter inputs simultaneously?

Yes, MCP73838T-FCI/UN supports simultaneous USB and AC adapter inputs, but implements strict priority: the AC adapter (VAC) dominates and powers the charge circuit when present, automatically disabling USB (VUSB) sourcing. This autonomous selection requires no external logic or firmware - the IC internally routes power and sets charge current based on the active input.

How does the TE pin on MCP73838T-FCI/UN function in practice?

The TE (Timer Enable) pin on MCP73838T-FCI/UN is an active-low input that enables or disables the internal safety timer. When pulled low (≤0.8 V), the timer runs (configurable for 4/6/8 hr); when high (≥2 V), timing is suspended. This allows hardware-level charge timeout control independent of host MCU - critical for fail-safe operation in headless or low-power systems using MCP73838T-FCI/UN.

What package type and thermal characteristics apply to MCP73838T-FCI/UN?

MCP73838T-FCI/UN uses a 3 mm × 3 mm 10-lead DFN package with exposed thermal pad (EP), internally tied to VSS. On a 4-layer JEDEC-standard board, its junction-to-ambient thermal resistance (θ_JA) is 41°C/W under natural convection - enabling reliable 1 A operation without forced airflow. The EP must be soldered to a solid PCB ground plane for effective heat transfer.

Can MCP73838T-FCI/UN be used with lithium-polymer batteries?

Yes, MCP73838T-FCI/UN is explicitly qualified for both Li-Ion and Li-Polymer single-cell batteries, as stated in its product description and electrical specifications. Its 4.20 V regulation, CC/CV algorithm, preconditioning, and thermal monitoring align with standard Li-Po charging requirements. No configuration change is needed - the same circuit design supports either chemistry when rated for 4.2 V nominal voltage.