BETAMCP73831Single-cell linear charge controller
Follow a cell through precharge, constant current and constant voltage.
MCP73831 is a linear charger for one compatible lithium-ion or lithium-polymer cell. Its internal pass transistor manages reduced-current preconditioning, constant-current charging, constant-voltage regulation and charge termination without an external power transistor. This page selects the -2AC option: 4.20 V regulation, 10% precharge current and 7.5% termination current. A 10 kΩ programming resistor sets nominal 100 mA fast charge. The three-state STAT output indicates the charging phase; it is not a battery-percentage measurement. Both SOT-23-5 and DFN-8 packages are mapped, including the DFN duplicate power contacts and exposed ground pad. The example uses a regulated 5.2 V source and a compatible 4.2 V-charge cell. External cell protection, temperature supervision and power-path management must be provided when the application requires them.
