LM3647 - Universal Battery Charger for Li-Ion, Ni-MH and Ni-Cd Batteries [Obsolete]

Datasheet	Obsolete Versions	Knowledge Base

Features

•	Auto-adaptive fast charge
•	High-resolution, accurate voltage monitoring prevents Li-Ion undercharge or overcharge
•	Fast charge, pre-charge and maintenance currents are provided. Different currents are selectable via external resistors.
•	Fast-charge termination by [Delta] temperature/[Delta] time, maximum voltage, maximum temperature, negative [Delta] voltage and maximum time
•	Dynamically detects battery insertion, removal, short circuit and bad battery without additional hardware
•	Supports charging of battery packs with 2-8 cells of Ni-Cd/Ni-MH or 1-4 cells of Li-Ion (1 cell of NiCd/NiMH can be supported by added external 2x voltage amplifier)
•	Three optional LED indicators and Buzzer output indicate operational modes
•	Ni-MH/Ni-Cd charge mode, Li-Ion charge mode or discharge mode can be selected manually
•	Supports control of current feedback power supply and constant current power supply

General Description

The LM3647 is a charge controller for Lithium-Ion (Li-Ion), Nickel-Metal Hydride (Ni-MH) and Nickel-Cadmium (Ni-Cd) batteries. More...

Applications

•	Battery charging systems for:
•	Portable consumer electronics
•	Audio/video equipment
•	Communications equipment
•	Point of sale devices
•	Power tools
•	Personal convenience products

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM3647 Universal Battery Charger for Li-Ion, Ni-MH and Ni-Cd Batteries	271 Kbytes	6-Oct-04	Download

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Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM3647IM	NONE	NATIONAL SEMICONDUCTOR	25 Oct 2005

General Description

The LM3647 is a charge controller for Lithium-Ion (Li-Ion), Nickel-Metal Hydride (Ni-MH) and Nickel-Cadmium (Ni-Cd) batteries. The device can use either a pulsed-current charging or a constant-current charging technique. The device can also be configured to discharge before charging. Throughout the charging sequence the LM3647 monitors voltage and/or temperature and time in order to terminate charging.

Charge termination methods are:

Negative delta voltage (-[Delta]V)
Optional: Delta temperature/delta time ([Delta]T/[Delta]t)
Backup: Maximum temperature
Backup: Maximum time
Backup: Maximum voltage

If both voltage and temperature fail to trigger the termination requirements, then the maximum time (configured by external hardware) steps in which terminates the charging.

In Ni-Cd/Ni-MH mode, four different charging stages are used:

Soft-start charge
Fast charge
Topping charge
Maintenance charge

In Li-Ion mode, four different charging stages are used:

Qualification
Fast Charge Phase 1, Constant Current
Fast Charge Phase 2, Constant Voltage
Maintenance charge

The charge current of the LM3647 is configured via external resistors, which in turn controls the duty cycle of the PWM switching control output. For cost-sensitive applications, the LM3647 charge controller cab be configured to use an external current source and no temperature sensor.

When using an external current source, the current is controlled by the LM3647 which turns the current source on and off. The LM3647 automatically detects the presence of a battery and starts the charging procedure when the battery is installed. Whenever an error occurs (e.g., short circuit, temperature too high, temperature too low, bad battery, charge time over, etc.) the LM3647 will stay in error mode until the battery is removed or it gets within the allowed charging temperature range. The LM3647 is available in a standard 20-lead SOIC surface mount package.

Application Notes

Title	Size in Kbytes	Date
AN-1165: Application Note 1165 Configuration Guide for LM3647 Reference Design	32 Kbytes	15-May-04	Download
AN-1164: Application Note 1164 LM3647 Reference Design User`s Manual	196 Kbytes	14-May-04	Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.

[Information as of 8-Nov-2009]