AS3020 is a complete constant - current and constant-voltage linear charger for single cell
lithium-ion and Lithium-Polymer batteries. Its SOT23-5L Package and low external component count make AS3020 ideally suited for portable applications.Furthermore the AS3020 is specifically designed to work within USB power specification. At the same time
AS3020 can also be used in the standalone lithium-ion
and Lithium-polymer battery charger.
No external sense resistor is needed and no
blocking diode is required due to the internal MOSFET
architecture. Thermal feedback regulates the charge
current to limit the die temperature during high power
operation or high ambient temperature. The charge
voltage is fixed at 4.2V and the charge current can be programmed externally with a single resistor. The A3020 automatically terminates the charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached.