SE9013 is a complete constant-current & constant voltage linear charger for single cell NiMH or others around 1.5V to 4.2V rechargeable batteries.  Its SOT-23 package and low external component count make SE9013 ideally suited for portable applications.  Furthermore, the SE9013 is specifically designed to work within USB power specification. 

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 SE9013 automatically terminates the charge cycle when the charge current drops to 1/5^th the programmed value after the final float voltage is reached.

When the input supply (wall adapter or USB supply) is removed, the SE9013 automatically enters a low current stage, dropping the battery drain current to less than 20uA.  The SE9013 can be put into shutdown mode, reducing the supply current to 9uA.

Other features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage. SE9013 is intentionally designed to have slightly negative Tempco.

SE9013 Includes the following Features:

Ø   Programmable Charge Current Up to 500mA.

Ø   No MOSFET, Sense Resistor or Blocking Diode Required.

Ø   Constant-Current/Constant-Voltage Operation with Thermal Protection to Maximize Charge Rate without Risk of Overheating.

Ø   Charges Single Cell Li-Ion Batteries Directly from USB Port.

Ø   Programmable Charge of 1.4-4.2V Voltage with ±1.5% Accuracy.

Ø   9uA Supply Current in Shutdown.

Ø   Soft-Start Limits Inrush Current.

Ø   Available in 6-Lead SOT-23 and PSOP-8 (Exposed Pad) Packages.

Link:http://www.seawardinc.com.cn/webeditor/uploadfile/20200601145146757.pdf