MCP73213T-A61I/MF: A Dual-Cell Li-Ion/Li-Polymer Charge Management Controller with Autonomous Power Source Selection

The increasing complexity of portable electronic devices demands sophisticated power management solutions that are both efficient and user-friendly. The MCP73213T-A61I/MF from Microchip Technology stands out as a highly integrated, linear charge management controller designed specifically for dual-series Li-Ion or Li-Polymer battery cells. Its most significant innovation lies in its ability to perform autonomous power source selection, seamlessly managing power flow between an external supply and the battery pack without requiring external microcontroller intervention.

This controller is engineered to simplify system design while enhancing end-product reliability. It operates by automatically detecting the presence of a valid input power source, typically an AC-DC wall adapter or a USB port. When input power is available, the IC powers the system load directly from this source while simultaneously charging the two-series battery pack. If the input power is removed or falls below a certain threshold, the device instantaneously and seamlessly switches to battery power, ensuring uninterrupted operation of the end equipment. This autonomous handoff is critical for applications where a constant power rail is mandatory.

The charging algorithm itself is meticulously crafted for safety and battery longevity. The MCP73213T-A61I/MF employs a precise constant-current/constant-voltage (CC/CV) charging profile with adjustable charge current through an external resistor. It integrates a highly accurate voltage regulation loop (±0.5% at 25°C) to ensure the two-series cells are charged to the correct termination voltage of 8.4V (4.2V per cell). Safety features are comprehensive, including built-in timer limits, thermal regulation to protect the IC during high-power operation, and reverse discharge protection to prevent the battery from draining back into the input source.

Additional key features include automatic recharge, which initiates a new charge cycle if the battery voltage falls below an internal threshold, and a power-good (STAT) output pin that provides a visual or logical indication of the charging status. Housed in a compact, 10-lead 3x3mm DFN package, the MCP73213T-A61I/MF is an ideal solution for space-constrained applications such as Bluetooth speakers, handheld medical instruments, industrial scanners, and premium toys.

ICGOOODFIND: The MCP73213T-A61I/MF is a superior integrated solution that eliminates the need for complex external circuitry to manage power sources and battery charging. Its hallmark feature of fully autonomous operation simplifies design, reduces firmware overhead, and enhances system reliability, making it an excellent choice for robust, portable dual-cell battery-powered products.

Keywords: Dual-Cell Charger, Autonomous Power Path Management, Constant-Current/Constant-Voltage (CC/CV), Li-Ion/Li-Polymer, Thermal Regulation.