Microchip Technology MCP73864T-I/ML

Overview

MCP73864T-I/ML from Microchip Technology is a dual-cell linear lithium-ion/lithium-polymer battery charge management controller with integrated P-channel pass transistor, current sense, and reverse-blocking protection. It delivers 8.2V or 8.4V regulation accuracy of ±0.5%, supports up to 1.2A fast-charge current, and operates across an input voltage range of 8.7V–12V. It is used in cradle chargers and portable medical instruments requiring precise dual-cell Li-ion charging.

For engineers reviewing the MCP73864T-I/ML datasheet, MCP73864T-I/ML pinout, MCP73864T-I/ML application, or MCP73864T-I/ML equivalent, this page provides verified technical context, validated pin functions, confirmed dual-cell voltage options (8.2V/8.4V), thermal regulation behavior, and real-world application constraints - all derived from Microchip's DS21893F specification.

Technical Context

The MCP73864T-I/ML implements a fully autonomous linear charge algorithm with preconditioning, constant-current (CC), and constant-voltage (CV) phases. Its internal P-channel MOSFET pass element eliminates external high-side switching components, while VSET pin selection determines whether CV regulation targets 8.2V (VSET = VSS) or 8.4V (VSET = VDD).

Charge termination occurs when current drops below ~8% of IREG or elapsed time exceeds 3.8 hours (CTIMER = 0.1 µF); safety timers are scaled by capacitor value on TIMER pin. Thermal regulation dynamically reduces charge current above ~100°C, and die temperature shutdown activates at 155°C with 10°C hysteresis.

Key Specifications

Pinout & Package

Package: 16-pin QFN (4 mm × 4 mm), exposed thermal pad (EP) electrically connected to VSS. Requires solder paste stencil and reflow profile compatible with fine-pitch QFN.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ24103ARHLR, MCP73864T-I/ML offers simpler layout and lower EMI but sacrifices efficiency above 500mA; compared with MCP73862T-I/ML, it provides identical charging performance with different end-of-charge signaling - making it a drop-in replacement only when LED logic is updated.

Availability

MCP73864T-I/ML is available at Aetrix Electronics and suitable for medical portable monitors, industrial handheld scanners, and point-of-sale cradle chargers requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for MCP73864T-I/ML 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 a focus on industrial, automotive, and medical applications.

The MCP7386X family was designed specifically for cost-sensitive, space-constrained Li-ion/Li-Po battery charging in portable electronics - integrating pass transistor, current sense, and safety logic to minimize external components.

FAQ

What is the function of the VSET pin on the MCP73864T-I/ML?

The VSET pin selects the constant-voltage regulation level for the MCP73864T-I/ML: tying VSET to VSS configures 8.2V output, while connecting it to VDD selects 8.4V. This choice directly determines the final float voltage applied to a dual-series Li-ion battery pack and must match the cell chemistry's recommended charging voltage - incorrect selection risks overvoltage and accelerated aging.

Can the MCP73864T-I/ML charge a single-cell Li-ion battery?

No, the MCP73864T-I/ML is designed exclusively for dual-series (2S) Li-ion or Li-polymer batteries, with regulation voltages of 8.2V or 8.4V. Its UVLO thresholds (8.40–9.05V start, 8.40–8.95V stop) and internal reference architecture are incompatible with single-cell operation - attempting to use it with a 4.2V battery will result in UVLO lockout and no charging.

How does the MCP73864T-I/ML handle thermal regulation during charging?

The MCP73864T-I/ML continuously monitors its die temperature and begins reducing charge current when junction temperature exceeds ~100°C. This thermal regulation scales ICHG downward to maintain safe operating temperature without terminating the charge cycle. The safety timer is also slowed to prevent premature timeout, ensuring full charge completion even under sustained thermal stress.

What is the purpose of the EP (exposed pad) on the MCP73864T-I/ML QFN package?

The EP on the MCP73864T-I/ML is an exposed thermal pad electrically connected to VSS inside the IC. It must be soldered to a dedicated PCB copper pour tied to the system ground plane. This path conducts heat away from the die during 1.2A charging, lowering θJA from 86.1°C/W (SOIC) to 47°C/W (QFN) - essential for maintaining reliability in compact, sealed enclosures.

Does the MCP73864T-I/ML support automatic recharge, and how is the threshold set?

Yes, the MCP73864T-I/ML supports automatic recharge when the battery voltage falls below VRTH. For MCP73864 devices, VRTH is set to VREG −200 mV to VREG −600 mV depending on VSET configuration - e.g., at 8.4V regulation, recharge triggers between 7.8V and 8.2V. This hysteresis prevents oscillation near the threshold and ensures stable reinitiation of the full CC-CV cycle.