LM3622 Datasheet, PDF (1/15 Pages) National Semiconductor (TI) – Lithium-Ion Battery Charger Controller

LM3622
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SNVS043B – FEBRUARY 2000 – REVISED APRIL 2013
LM3622 Lithium-Ion Battery Charger Controller
Check for Samples: LM3622
FEATURES
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•2 Versions for Charging of 1 Cell (4.1V or 4.2V)
or 2 Cells (8.2V or 8.4V)
• Versions for Coke or Graphite Anode
• Precision (±30mV/Cell) End-of-Charge Control
• Wide Input Range: 4.5V-24V
• Low Battery Drain Leakage: 200nA
• 15 mA Available to Drive Low Cost PNP
APPLICATIONS
• Cellular Phone Cradle Charger
• PDA/Notebook Cradle Charger
• Camcorder Cradle Charger
DESCRIPTION
The LM3622 is a charge controller for Lithium-Ion
batteries. This monolithic integrated circuit accurately
controls an external pass transistor for precision
Lithium-Ion battery charging. The LM3622 provides a
constant voltage or constant current (CVCC)
configuration that changes, as necessary, to optimally
charge lithium-ion battery cells. Voltage charging
versions (4.1V, 4.2V, 8.2V, and 8.4V) are available
for one or two cell battery packs and for coke or
graphite anode battery chemistry.
The LM3622 accepts input voltages from 4.5V to
24V. Controller accuracy over temperature is
±30mV/cell for A grade and ±50mV/cell for the
standard grade. No precision external resistors are
required. Furthermore, the LM3622's proprietary
output voltage sensing circuit drains less than 200nA
from the battery when the input source is
disconnected.
The LM3622 circuitry includes functions for regulating
the charge voltage with a temperature compensated
bandgap reference and regulating the current with an
external sense resistor. The internal bandgap insures
excellent controller performance over the operating
temperature and input supply range.
The LM3622 can sink 15mA minimum at the EXT pin
to drive the base of an external PNP pass transistor.
It also has low-voltage battery threshold circuitry that
removes this drive when the cell voltage drops below
a preset limit. The LV_SEL pin programs this threshold
voltage to either 2.7V/cell or 2.15V/cell. The low-
voltage detection, which is a user enabled feature,
provides an output signal that can be used to enable
a "wake up charge" source automatically to
precondition a deeply discharged pack.
The LM3622 is available in a standard 8-lead SOIC
surface mount package.
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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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