Constant-current, constant-voltage and constant-temperature current supply of a battery charger

摘要

Provided is a current supply for providing a charge current to a load. The current supply includes: a driving transistor, providing the charge current to the load; a sensing transistor, limiting the charge current; a pulling low transistor, pulling low a controlling node which controls the driving transistor and the sensing transistor; a constant voltage controller, pulling up the controlling node, controlling the conduction state of the driving transistor and accordingly maintaining the voltage across the load at the first reference voltage, when a voltage across the load rises up and comes close to a first reference voltage; and a constant current controller, controlling the controlling node and the pulling low transistor to limit the charge current to be constantly provided to the load, when the voltage across the load drops much lower than the first reference voltage.