LM3647 Datasheet, PDF (1/19 Pages) National Semiconductor (TI) – Universal Battery Charger for Li-Ion, Ni-MH and Ni-Cd Batteries

OBSOLETE
LM3647
www.ti.com
SNOS517H – MARCH 2000 – REVISED APRIL 2013
LM3647 Universal Battery Charger for Li-Ion, Ni-MH and Ni-Cd Batteries
Check for Samples: LM3647
FEATURES
1
•2 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 Δ Temperature/Δ
Time, Maximum Voltage, Maximum
Temperature, Negative Δ 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
APPLICATIONS
• Battery Charging Systems for:
– Portable Consumer Electronics
– Audio/Video Equipment
– Communications Equipment
– Point of Sale Devices
– Power Tools
– Personal Convenience Products
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 (−ΔV)
• Optional: Delta Temperature/Delta Time (ΔT/Δt)
• 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.
1
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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