名称：一级代理VT5024

VT5024 is a complete constant-current & constant
voltage linear charger for single cell lithium-ion batteries.
Its SOT-23 package and low external component count
make VT5024 ideally suited for portable applications.
Furthermore, the VT5024 is specifically designed to work
within USB power specification. At the same time,
VT5024 can also be used in the standalone lithium-ion
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 VT5024 automatically terminates the
charge cycle when the charge current drops to 1/10 th the
programmed value after the final float voltage is reached.
When the input supply (wall adapter or USB supply)
is removed, the VT5024 automatically enters a low current
stage, dropping the battery drain current to less than 2uA.
The VT5024 can be put into shutdown mode, reducing the
supply current to 25uA