The MCP73831T-2ACI/OT: A Compact Powerhouse for Single-Cell Li-Ion/Li-Polymer Charging

In the realm of portable electronics, efficient and reliable battery charging is paramount. The Microchip MCP73831T-2ACI/OT stands out as a highly integrated, full-featured linear charge management controller designed specifically for single-cell Lithium-Ion or Lithium-Polymer batteries. This miniature yet powerful IC encapsulates all the necessary circuitry to accurately control the charging cycle from a wide range of input sources, making it an ideal solution for space-constrained applications.

The core functionality of the MCP73831T-2ACI/OT is its meticulous management of the precise charging protocol required by lithium-based chemistries. It seamlessly executes a complete charge cycle, beginning with a pre-conditioning trickle charge for deeply depleted cells. Once the battery voltage rises sufficiently, it enters the constant-current (CC) phase, delivering the fast charge. Finally, as the battery approaches its peak voltage, the controller transitions to the constant-voltage (CV) phase, tapering the current until charge termination. This process is highly accurate, with a preset regulation voltage of 4.2V with a tolerance of ±0.75%, ensuring both safety and the longevity of the battery.

A key feature of this particular variant (denoted by the `-2A` suffix) is its programmable charge current, set by a single external resistor. This offers designers significant flexibility to tailor the charging speed to the thermal and capacity constraints of their application, from low-current devices like Bluetooth headsets to higher-capacity applications. Furthermore, the IC integrates multiple safety protections, including thermal regulation to automatically reduce charge current if excessive junction temperature is detected, preventing damage to both the charger and the battery.

Housed in a tiny 5-pin SOT-23 package, the MCP73831T-2ACI/OT exemplifies minimal external component count. It requires only the current-set resistor and two bypass capacitors to form a complete charging solution, drastically saving valuable PCB space. Its ability to operate from an input voltage range of 3.75V to 6.0V allows it to be powered from a standard USB port or a regulated DC supply.

ICGOODFIND: The Microchip MCP73831T-2ACI/OT is an exceptionally compact and cost-effective solution for single-cell lithium battery charging. Its high integration, precision regulation, robust safety features, and design flexibility make it a superior choice for a vast array of portable, handheld, and space-conscious consumer electronics.

Keywords:

Battery Management

Constant-Current/Constant-Voltage (CC/CV)

Linear Charger

Programmable Charge Current

Thermal Regulation