FS3871 is a lithium battery charging management chip produced by Fortune Semiconductor Corp. It is suitable for charging single-cell or dual-cell lithium-ion and lithium-polymer batteries. The chip features dynamic compensation of battery pack internal resistance, optional battery temperature monitoring, automatic recharge, minimum current termination charging, etc.
The FS3871 is a lithium‑battery charge‑management IC produced by Fortune Semiconductor. It supports single‑cell (4.2 V) and dual‑cell (8.4 V) Li‑Ion or Li‑Polymer batteries and provides constant‑voltage/constant‑current charging, dynamic internal‑resistance compensation, and optional temperature monitoring.
The manual details the chip’s pin functions, internal block diagram, typical application circuits, charging stages, temperature‑monitoring method, and includes schematics for several evaluation boards (one‑cell, two‑cell, three‑cell, Bluetooth‑power, etc.) to help designers integrate the device quickly. This manual is written in Chinese.
| Supported battery voltage | Single‑cell 4.2 V, Dual‑cell 8.4 V |
|---|---|
| Pre‑charge current | ≈ 0.1 × constant‑current charge current (Ireg) |
| Charging current programming | Set by resistor Rsns on SNS pin |
It can charge single‑cell (4.2 V) or dual‑cell (8.4 V) Li‑Ion and Li‑Polymer batteries.
The charging current is programmed by connecting a resistor (Rsns) to the SNS pin.
Temperature is sensed via the TS pin and an external thermistor network; charging stops if the temperature is outside the defined range.