SC802_08 Datasheet, PDF (1/18 Pages) Semtech Corporation – Fully Integrated Lithium-Ion Battery Charger System with Timer

SC802/SC802A
POWER MANAGEMENT
Fully Integrated Lithium-Ion
Battery Charger System with Timer
Features
„ Integrated charger with pass FET, reverse-blocking
diode, sense resistor, timer, and thermal protection
„ Battery Voltage — 4.1V, 4.2V, and adjustable
„ Programmable pre-charge, fast-charge, & termina-
tion current
„ Battery voltage controlled to 1% accuracy
„ Soft-start for glitch-free adaptor plug-in
„ Continuous charge current — Up to 1.5A
„ Charge current monitor output for microcontroller or
ADC interface
„ Input voltage range — 4.3V to 14V
„ Battery Drain when not charging — 0.1μA
„ Operates without a battery in regulated LDO mode
„ Small 4 x 4(mm) 16 lead MLPQ package
„ NTC thermistor sense input
„ Adjustable up to 6 Hour programmable charge timer
„ Over-current protection in all charging states
„ Over-voltage protection
„ Remote Kelvin sensing at the battery terminals
„ ADC input current control capable
„ Status output for charging and end of charge cycle
„ Charges Li-Ion, Li-Polymer, NiCd, and NiMH Batteries
Applications
„ Cellular phones and PDA’s
„ Handheld meters
„ Charging stations
„ Handheld computers
„ Digital cameras
„ Programmable current source
Description
The SC802 and SC802A are fully integrated, single cell,
constant-current/constant-voltage Lithium-Ion/Lithium
Polymer battery chargers. With an integrated timer and
complete charge control algorithm, the devices are opti-
mized for stand-alone charger applications. They provide
for programmable pre-charge, fast-charge, and termina-
tion current settings. The devices can be programmed to
terminate the charge cycle based on the output current or
the time-out of the programmable timer. The fast-charge
current is typically set with an external resistor but can be
modified with the analog fast-charge input to allow a
Power Management Controller to control the fast-charge
current setting via DAC.
The 14V input voltage range of the SC802 and SC802A
eliminates additional protection circuitry required by
other 5V chargers in the event of faulty adapters.
Reference ground and battery sense inputs are provided
to allow Kelvin connections, to eliminate errors due to I×R
voltage drops during charging.
The output voltage to the battery is controlled to within
1% of the programmed voltage for either 4.1V or 4.2V. The
SC802 and SC802A can also function as a general purpose
current sources, such as for charging nickel-cadmium
(NiCd) and nickel-metal-hydride (NiMH) batteries.
The SC802A version of the device is optimized for high
termination current applications.
Typical Application Circuit
CHARGER VIN
C_VCC
1μF
R_NPU
RIPRGM
R_NTC
Battery
Thermistor
R_ITERM
SC802/SC802A
VCC1
CPB
VCC2 CHRGB
IPRGM RTIME
EN_NTC VPRGM
ITERM
BSEN
BIPB
VOUT1
GND
VOUT2
RFGND
AFC
AFC I_SET
CHARGE
CHARGER
PRESENT
BAT. _CVOUT
2.2μF
R_RTIME
October 30, 2008
© 2008 Semtech Corporation
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