The LM3420 series of controllers are monolithic integrated circuits designed for charging and end-of-charge 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 open-emitter 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 end-of-charge voltage threshold for lithium-ion rechargeable batteries. The premium grade LM3420A is available with an initial voltage threshold tolerance of ±0.5%, while the standard grade LM3420 has an initial voltage threshold tolerance of ±1%.

The LM3420 is available in a sub-miniature 5-lead surface mount package thus allowing very compact designs.

• 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 A (Typ.)
• Tiny SOT-23-5 package

• Number of series cells
• 1, 2, 3, 4
• Charge current (Max) (A)
• 0.015
• Operating Vin (Max) (V)
• 20
• Cell chemistry
• Li-Ion/Li-Polymer
• Battery charge voltage (Min) (V)
• 4.2
• Battery charge voltage (Max) (V)
• 4.2
• Absolute Vin (safety rating) (Max) ((V))
• 20
• Control interface
• Standalone (RC-Settable)
• Features
• IC thermal regulation
• Operating Vin (Min) (V)
• 13
• Rating
• Catalog

LM3420的完整型号有：LM3420AM5-8.4/NOPB、LM3420M5X-8.4/NOPB，以下是这些产品的关键参数及官网采购报价：

LM3420AM5-8.4/NOPB，工作温度：-40 to 125，封装：SOT-23 (DBV)-5，包装数量MPQ：1000个，MSL 等级/回流焊峰值温度：Level-1-260C-UNLIM，引脚镀层/焊球材料：SN，TI官网LM3420AM5-8.4/NOPB的批量USD价格：2.933（1000+）

LM3420M5X-8.4/NOPB，工作温度：-40 to 125，封装：SOT-23 (DBV)-5，包装数量MPQ：3000个，MSL 等级/回流焊峰值温度：Level-1-260C-UNLIM，引脚镀层/焊球材料：SN，TI官网LM3420M5X-8.4/NOPB的批量USD价格：2.933（1000+）