ONE-CELL STANDALONE LINEAR LITHIUM BATTERY CHARGER 
  
  
 
  
DESCRIPTION  
  
UTC UB2017 is a complete, constant current and constant voltage  
linear charger for single cell lithium-ion batteries. Its small size and  
ability to regulate low charge currents make UTC UB2017 especially  
well-suited for portable applications using low capacity rechargeable  
lithium-ion coin cells. Furthermore, UTC UB2017 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 MOSFET architecture. The charge  
voltage is fixed at 4.2V, and the charge current can be programmed  
externally with a single resistor. UTC UB2017 automatically  
terminates a charge cycle when the charge current drops to 1/10th  
the programmed value after the final float voltage is reached. 
  
  
FEATURES 
  
  
* Programmable Charge Current Up to 500mA.  
* No External MOSFET, Sense Resistor or Blocking Diode Required.  
* Complete linear charger in Thin SOT Package for Single Cell / Coin Cell Lithium-lon Batteries.  
* Constant Current / Constant Voltage Operation with Thermal Regulation to Maximize Charge Rate Without Risk  
of Overheating.  
* Charges Single Cell Li-lon Batteries Directly form USB Port.  
* Preset 4.2V Charge Voltage with High Accuracy about ±1.2%.  
* Automatic Recharge.  
* 2.9V Trickle Charge Threshold.  
* 25µA Max Supply Current in Shutdown Mode.  
* Charge Status Output Pin.     |