| 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 |
- 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
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.