ME4057 is a complete constant-current/constant voltage linear  charger  for  single  cell  lithium-ion batteries.  With  a
thermally  enhanced 8-PIN SOP  package on  the  bottom and low  external  component  count  make  the  ME4057
ideally  suited  for  portable  applications. Furthermore  the ME4057 is specifically designed to work within USB power
specifications.No  external  sense  resistor  is  needed and  no  blocking diode  is  required  due  to  the  internal  PMOSFET
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 ME4057 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  ME4057 automatically  enters  a  low  current
state dropping  the  battery  drain  current  to  less  than 2μA.The ME4057 can be put into shutdown mode reducing
the supply current to 55μA. Other  features  include  Battery  temperature  monitor, under-voltage lockout, automatic recharge and two status pins to indicate charge and charge termination.

Applications
Typical charge cycle（1000mAh battery）
●Cellular Telephones
●Digital Still Cameras
●MP3 Players
●Bluetooth Applications
●Portable Devices
●USB Bus-Powered Chargers

●Protection of battery cell reverse connection
● Programmable charge current up to 1A  
●No  MOSFET sense  resistor  or  blocking  diode required
●Complete linear  Charger  in  SOP8  Package  for
single Cell Lithium-Ion Batteries.
●Constant-Current/Constant-Voltage  operation with  thermal  regulation  to  maximize  Rate
   Without risk of overheating.
● Preset 4.2V charge voltage with ±1% accuracy
● Automatic Recharge
●  Two Status  Indication  for Charge  status,  no battery and battery failure indicators
● C/10 charge termination
● 55μA supply current in shutdown
● 2.9V trickle current charge threshold
● Soft-Start limits inrush current
● Battery Temperature Sensing 
● Available in SOP8-PP package