Cxlb7207 is a PWM Buck mode single lithium battery charging management integrated circuit, which independently manages the charging of a single lithium battery. It has the advantages of small footprint, few peripheral components and simple use. With trickle, constant current and constant voltage charging modes, the cxlb7207 is very suitable for lithium battery charging management. In constant voltage charging mode, the cxlb7207 modulates the battery voltage to 4.2V, which can also be adjusted upward through an external resistance; in constant current charging mode, the charging current is set through an external resistance. The internal adaptive circuit can automatically adjust the charging current according to the current output capacity of the input power supply. The user does not need to consider the worst case, and can maximize the current output capacity of various input power supplies, which is very suitable for the application of power supply with limited current output capacity such as USB interface. For deep discharge lithium battery, when the battery voltage is lower than 66.5% of the constant voltage charging voltage (typical value), cxlb7207 uses 17.5% of the constant current charging current set to trickle charge the battery. In the constant voltage charging stage, the charging current decreases gradually.