Microchip Technology MCP73837-FJI/MF

Overview

MCP73837-FJI/MF 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, 4.20 V fixed charge voltage, thermal regulation, and dual open-drain status outputs (STAT1/STAT2) - used in portable medical devices and ultra-mobile consumer electronics requiring dual-source charging.

For engineers reviewing the MCP73837-FJI/MF datasheet, MCP73837-FJI/MF pinout, MCP73837-FJI/MF application, or MCP73837-FJI/MF equivalent, key selection criteria include its 10-lead 3 mm × 3 mm DFN package, programmable AC charge current (15–1000 mA), USB-selectable 100/500 mA modes, integrated reverse discharge protection, and power-good output (PG) exclusive to the MCP73837 variant.

Technical Context

The MCP73837-FJI/MF implements a CC/CV charge algorithm with factory-set 4.20 V regulation, preconditioning for deeply depleted cells, and automatic recharge triggered at 94% of VREG. Its autonomous source selection prioritizes VAC over VUSB when both are present, enforcing USB 2.0 current limits (100 mA/500 mA) via PROG2 logic level.

Thermal regulation dynamically reduces charge current above ~150°C junction temperature, while UVLO provides separate thresholds for VAC (4.15 V start) and VUSB (3.45 V start) with built-in hysteresis. The PG output signals valid input supply presence, and THERM supports NTC thermistor-based temperature monitoring with 50 µA bias current.

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 performance (θ_JA = 41°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ24075RGTR and MCP73831T-2DCI/OT, the MCP73837-FJI/MF uniquely combines autonomous VAC/VUSB selection, PG output for input validation, and full thermistor interface in a 3×3 mm DFN - making it optimal for compact, dual-source, medically rated portable systems.

Availability

MCP73837-FJI/MF is available at Aetrix Electronics and suitable for smartphone battery charging, portable medical monitors, Bluetooth headset docks, ultra-mobile PDAs, and handheld diagnostic tools requiring stable component supply and long-term industrial availability.

Supply support for MCP73837-FJI/MF 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 for industrial, automotive, and consumer applications.

The MCP73837/8 product line delivers highly integrated, autonomous linear battery chargers optimized for space-constrained portable electronics with dual-input power sources and stringent safety requirements.

FAQ

What is the exact charge voltage regulation accuracy of the MCP73837-FJI/MF?

The MCP73837-FJI/MF provides ±0.5% voltage regulation accuracy at 4.20 V over −5°C to +55°C ambient temperature. This specification is guaranteed across process, voltage, and temperature (PVT) corners and is measured under standard test conditions per DS20002071C-page 4. The MCP73837-FJI/MF achieves this without external trimming components, relying on internal precision bandgap and feedback architecture.

Does the MCP73837-FJI/MF support both AC adapter and USB charging simultaneously?

No - the MCP73837-FJI/MF performs autonomous source selection, not simultaneous charging. When both VAC and VUSB are present, the device prioritizes VAC and disables USB current path. Only one source powers the charge circuit at any time, preventing backfeed and ensuring compliance with USB current limits. This behavior is hardwired and requires no firmware intervention.

How is the safety timer configured on the MCP73837-FJI/MF?

The safety timer on the MCP73837-FJI/MF is factory-configured and not user-programmable via pins or registers. It is offered in three fixed durations - 4 hours, 6 hours, or 8 hours - selected at order time via part number suffix. The MCP73837-FJI/MF corresponds to the 4-hour timer option. Timer expiration forces charge termination and asserts STAT1/STAT2 high-impedance states.

Can the MCP73837-FJI/MF be used with lithium-polymer batteries?

Yes - the MCP73837-FJI/MF is explicitly qualified for both Li-ion and Li-polymer chemistries. Its 4.20 V regulation voltage matches standard single-cell LiPo nominal charging profiles, and its integrated thermal regulation, preconditioning, and reverse discharge protection apply equally to both chemistries. No configuration changes are required when switching between Li-ion and Li-polymer battery packs.

What is the function of the PG pin on the MCP73837-FJI/MF?

The PG (Power-Good) pin on the MCP73837-FJI/MF is an open-drain output that pulls low when a valid input supply (VAC ≥ 4.15 V or VUSB ≥ 3.45 V) is detected and UVLO is cleared. It remains high-impedance during shutdown, preconditioning, or fault conditions. This signal allows host systems to confirm input presence before enabling downstream rails or initiating firmware boot sequences - a feature exclusive to the MCP73837 series.