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www.semtech.com
SC802/SC802A
Fully Integrated Lithium-Ion
Battery Charger System with Timer
POWER MANAGEMENT
Description
June 13, 2005
Features
Fully integrated charger with FET pass transistor,
reverse-blocking diode, sense resistor, timer, and
thermal protection
Complete voltage ranges of 4.1V, 4.2V & adjust-
able
Programmable precharge, fastcharge & termina-
tion current
Battery voltage controlled to 1% accuracy
Soft-start for glitch-free adaptor plug-in
Up to 1A continuous charge current
Charge current monitor output for microcontroller
or ADC interface
Input voltage range from 4.3V to 14V
0.1
μ
A battery drain current in shutdown and
monitor modes
Operates without a battery in regulated LDO mode
Small 4mm x 4mm 16 lead MLP package
NTC thermistor sense input
Adjustable 6 Hour programmable charge timer
Over current protection in all charging modes
Over voltage protection
Remote Kelvin sensing at the battery terminals
ADC input control capable
Status output communicates charging and end of
charge cycle
Charges Li-Ion, Li-Polymer, NiCd and NiMH
Batteries
Applications
Cellular phones
PDA’s
Handheld meters
Charging stations
Handheld computers
Digital cameras
Programmable current source
Typical Application Circuit
The SC802 is a fully integrated, single cell, constant-cur-
rent/constant-voltage Lithium-Ion\Lithium Polymer bat-
tery charger. With an integrated timer and complete
charge control algorithm, the SC802 is well suited for
stand-alone charger applications. The SC802 contains
programmable pre-charge, fast-charge, and termination
current settings. The SC802 can be programmed to ter-
minate charge 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 modi-
fied with the analog fast charge input to allow a Power
Management Controller to control the fastcharge current
setting via DAC.
The 14V input voltage range of the SC802 eliminates
additional protection circuitry required by other 5V charg-
ers in the event of faulty adapters.
Reference ground and battery sense inputs are provided
to allow Kelvin connections to eliminate IR 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 can also function as a general purpose cur-
rent source or as a current source for charging nickel-
cadmium (NiCd) and nickel-metal-hydride (NiMH) batter-
ies using NTC termination.
The SC802A version of the device is optimized for high
termination current applications. All descriptions and text
refering to the SC802 also apply to the SC802A unless
otherwise noted.
CHARGER VIN
t
RT1
THERMISTOR
CHARGER
PRESENT
ADC Iset
R6
1K
R5
1K
R3
R
R4
C1
1uF
R1
SC802
14
13
1
16
3
7
4
8
6
15
9
12
2
10
11
5
VCC
VCC
BSEN
VOUT
IPRGM
EN/NTC
ITERM
BIPB
GND
VOUT
AFC
RTIM
VPRGM
CHRGB
CPB
RFGND
CHARGE
C2
2.2uF
R2
BATTERY