RT9451GQW

The charger automatically detects a USB wall charger through the D+D − detection circuit, which allows for automatic detection of a USB wall charger. When a wall charger is detected, the input current limit will automatically increase from 500mA to 975mA. This detection mechanism enables the charger to adjust its settings accordingly based on the type of power source connected.

The charger uses three phases to charge the battery: low current pre-charge, constant current fast charge, and constant voltage trickle charge.

The main function of the RT9451 integrated chip is to serve as a single-cell Li-ion and Li-polymer battery charger for portable applications. It integrates a synchronous PWM controller with power MOSFETs to provide Minimum Input Voltage Regulation (MIVR), input current sensing, high accuracy current and voltage regulation, and charge termination in a compact package for space-limited devices. Additionally, it features USB On-The-Go (OTG) function and USB charger detection (DPDM detection) function.