ETA4257

ETA4257 is a single cell, fully integrated constant current (CC)/constant voltage (CV) Li-ion battery charger. Its compact package with minimum external components requirement makes the ETA4257 ideal for portable applications. No external sense resistor or blocking diode is necessary for the ETA4257. Build-in thermal feedback mechanism regulates the charge current to control the die temperature during high power operation or at elevated ambient temperature. The ETA4257 has a pre-charge function for trickle charging deeply discharged batteries. The fast charge current can be programmed by an external resistor. CV regulation mode is automatically enabled once the battery’s charging curve reaches the constant voltage portion. The output current then decays and is finally terminated once the charge current drops to 1/5 of the programmed value. The ETA4257 keeps monitoring the battery voltage and enables a new charge cycle once the voltage drops by 200mV below the CV value.