View lm3420 datasheet:

April 1996 LM3420-4 2 -8 2 -8 4 -12 6 -16 8 Lithium-Ion Battery Charge Controller General Description The LM3420 series of controllers are monolithic integrated The LM3420 is available in a sub-miniature 5-lead SOT23-5 circuits designed for charging and end-of-charge control for surface mount package thus allowing very compact de- Lithium-Ion rechargeable batteries The LM3420 is available signs in five fixed voltage versions for one through four cell charg- er applications (4 2V 8 2V 8 4V 12 6V and 16 8V respec- Features tively) Y Voltage options for charging 1 2 3 or 4 cells Included in a very small package is an (internally compen- Y Tiny SOT23-5 package sated) op amp a bandgap reference an NPN output tran- Y Precision (0 5%) end-of-charge control sistor and voltage s