LM3420

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community LM3420 SNVS116E – MAY 1998 – REVISED DECEMBER 2014 LM3420 8.4-V Li-Ion Battery Charge Controller 1 Features 1 Input Voltage Range: up to 20 V Voltage Options for Charging 1, 2, 3, or 4 Cells Output Current up to 15 mA Precision (0.5%) End-of-Charge Control – LM3420 ±1% – LM3420A ±0.5% Drive Capability for External Power Stage Temperature Drift Curvature Correction for Voltage Stability Low Quiescent Current, 85 μA (Typ.) Tiny SOT-23-5 package 2 Applications Lithium-Ion Battery Charging Suitable for Linear and Switching Regulator Charger Designs space space 3 Description The LM3420 series of controllers are monolithic integrated circuits designed for charging and end-ofcharge control for lithium-ion rechargeable batteries. The LM3420 is available in an 8.4-V version for one through four cell charger applications. Included in a very small package is an (internally compensated) op amp, a bandgap reference, an NPN output transistor, and voltage setting resistors. The amplifier's inverting input is externally accessible for loop frequency compensation. The output is an openemitter NPN transistor capable of driving up to 15 mA of output current into external circuitry. A trimmed precision bandgap reference utilizes temperature drift curvature correction for excellent voltage stability over the operating temperature range. The LM3420 series allows for precision endof-charge...