ETA钰泰 ETA1918Q3Q 开关式锂电池充电器IC

　　DESCRIPTION

　　ETA1918S is a switching Li-lon battery charger with dynamic power-path control and input current limiting. When a battery is connected, depending on the battery voltage, the DC-DC switching regulator either pre-conditions, fast-charges the battery or just regulates a system voltage (Vsvs) to a preset voltage. It does not require an external sense resistor for current sensing. The charging current is determined by programming ISET1 or ISET2 pin, depending on the state of the nUSB_DET. One should pull nUSB_DETlow, if an USB adapter input is present, the charge current is set by ISET2; otherwise, it is set by ISET1. When the battery voltage reaches the termination voltage i.e. 4.2V. the charging path disconnects SYS to BATT. The ETA1918S also includes a dynamic power path when the SYS load current exceeds current limit of the DCDC regulator internally set, the SYS voltage falls below VBATT, ETA1918S turns on the power-path to supplement the system load through the battery.