Microchip Technology MCP73837T-FJI/MF

Overview

MCP73837T-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, 4.20V fixed charge voltage, 100 mA to 1000 mA programmable AC charge current, and thermal regulation. It serves as the primary charge control IC in compact portable devices requiring dual-input power path management.

For engineers reviewing the MCP73837T-FJI/MF datasheet, MCP73837T-FJI/MF pinout, MCP73837T-FJI/MF application, or MCP73837T-FJI/MF equivalent, key selection considerations include its 3 mm × 3 mm 10-lead DFN package, dual open-drain status outputs (STAT1/STAT2), integrated reverse discharge protection, PG output for power-good monitoring, and thermistor-based battery temperature sensing capability.

Technical Context

The MCP73837T-FJI/MF implements a CC/CV charge algorithm with factory-set 4.20V regulation, preconditioning for deeply depleted cells, and automatic recharge at 94% of VREG. Its autonomous power source selection logic prioritizes VAC over VUSB when both are present, enforcing USB 2.0 current limits (100 mA/500 mA) via PROG2 digital input.

Thermal regulation dynamically reduces charge current above 150°C junction temperature, while the internal 50 µA thermistor bias current supports standard 10 kΩ NTC sensors. The device integrates pass FETs, current sense, UVLO (3.45V start for USB, 4.15V for AC), and safety timer functionality - all within a single 3×3 mm DFN package with exposed thermal pad.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ24075RGTR and TP4056, the MCP73837T-FJI/MF uniquely delivers integrated PG output, factory-set 4.20V precision regulation, and true autonomous AC-over-USB source selection - making it optimal for space-constrained dual-input portable designs requiring certified thermal and safety compliance.

Availability

MCP73837T-FJI/MF is available at Aetrix Electronics and suitable for smartphones, portable media players, digital cameras, and Bluetooth headsets requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MCP73837T-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 Inc. is a leading provider of microcontroller, analog, FPGA, and mixed-signal semiconductor solutions headquartered in Chandler, Arizona.

The MCP73837/8 product line was designed specifically for compact, dual-input Li-ion battery charging in portable consumer electronics - emphasizing integration, thermal safety, and USB/AC source arbitration without host processor involvement.

FAQ

What is the exact charge voltage regulation accuracy of the MCP73837T-FJI/MF?

The MCP73837T-FJI/MF provides ±0.5% voltage regulation accuracy at 4.20V over -5°C to +55°C ambient temperature. This specification is guaranteed across the full operating range and directly supports JEITA-compliant charging profiles for single-cell Li-ion batteries. The MCP73837T-FJI/MF achieves this using an internal bandgap reference and trimmed feedback network - no external calibration is required.

Does the MCP73837T-FJI/MF support automatic recharge, and what is its threshold?

Yes, the MCP73837T-FJI/MF supports automatic recharge with a factory-set threshold of 94.0% of VREG (i.e., 3.948V for 4.20V nominal). When battery voltage falls below this level after charge completion, the device reinitiates the CC/CV cycle. This behavior is enabled by default and does not require external components - the MCP73837T-FJI/MF handles detection, qualification, and restart autonomously.

How does the MCP73837T-FJI/MF handle thermal regulation during charging?

The MCP73837T-FJI/MF incorporates die-temperature-based thermal regulation that begins reducing charge current when junction temperature exceeds 150°C, with 10°C hysteresis. This foldback mechanism protects both the IC and battery under high ambient conditions or insufficient PCB copper. Unlike simple shutdown, thermal regulation maintains partial charging capability - ensuring progress continues while preventing thermal runaway. The MCP73837T-FJI/MF's 41°C/W θJA enables effective heat dissipation in typical 4-layer board layouts.

What is the function of the PG pin on the MCP73837T-FJI/MF, and how is it used?

The PG (Power-Good) pin on the MCP73837T-FJI/MF is an open-drain output that asserts low when a valid input supply (VAC or VUSB) is detected above UVLO thresholds. It provides hardware-level confirmation of input presence - enabling system-level power sequencing, host wake-up, or LED indication without software polling. The MCP73837T-FJI/MF's PG output is electrically identical to STAT1/STAT2 but dedicated solely to input validation, distinguishing it from the MCP73838 variant which replaces PG with TE (Timer Enable).

Can the MCP73837T-FJI/MF be used with batteries requiring 4.35V or higher charge voltage?

No, the MCP73837T-FJI/MF is factory-configured for 4.20V regulation only. While the broader MCP73837/8 family offers 4.20V, 4.35V, 4.40V, and 4.50V variants, the "T-FJI/MF" suffix explicitly denotes the 4.20V version. Using it with 4.35V+ batteries risks undercharging and reduced capacity. For higher-voltage cells, select the appropriate variant (e.g., MCP73837T-2I/MF for 4.35V) - the MCP73837T-FJI/MF's internal reference and feedback network are not user-adjustable.