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SC805
Miniature Integrated High Current
Lithium-Ion Battery Charger
POWER MANAGEMENT
C1
1uF
BATTERY
R7
1k
SC805
1
7
9
4
5
10
2
8
3
6
VCC
EN/NTC
RTIME
IPRGM
ITERM
CHRGB
VCCIL
NOBAT
VOUT
GND
R4
3.01k
t
RT1
Thermistor
D2
LED
C1
2.2uF
Charging
Indicator
D3
LED
R5
3.01k
R2
3.01k
R1
3.01k
SC805 typical Application Circuit
D1
LED
CHARGER VIN
R3
3.01k
Adapter
Present
Indicator
Charge
Complete
Indicator
R6
1k
August 22, 2005
Description
Features
Applications
Typical Application Circuit
Fully integrated charger with FET pass transistor,
reverse-blocking diode, sense resistor and thermal
protection
High Accuracy Charge Current*
Tiny 3mm x 3mm 10 lead MLP package
Programmable precharge, fastcharge & termination
current
Battery voltage controlled to 1% accuracy
Built in timer for protection and complete charging
NTC interface with battery detection
Soft-start for step load and adaptor plug-in
Up to 1A continuous charge current
Input voltage range from 3V to 6V allows seamless
charging from current limited adapter
Provides adapter voltage VCCIL to power external
accessories
Battery Present detection and output indicator
Operates in charger or LDO-mode without battery
0.1A battery drain current in shutdown and
monitor modes
Over current protection in all charging modes
CHRGB output communicates charging and end of
charge cycle
*Patent Pending
The SC805 is a fully integrated, single cell, constant-cur-
rent (CC)/constant-voltage (CV) Lithium-Ion battery
charger in a tiny 3x3 mm thermally enhanced lead free
MLP package. The SC805 can operate as a stand-alone
charger or in conjunction with a Power Management Con-
troller (PMIC).
The SC805 has a pre-charge function for trickle charging
deeply discharged batteries. The fast charge current is
enabled automatically when the battery voltage reaches
the required threshold. When the battery reaches the
constant voltage or CV portion of the charge curve the
SC805 switches to CV regulation mode. In this mode
the output current decays as the battery charges until
the termination current is reached and the SC805 sig-
nals the charge cycle is complete. The SC805 can be
configured to continue charging for a predetermined time
before turning off, or to turn off immediately upon termi-
nation. After turning off its output, The SC805 enters
monitor mode. If the battery voltage drops by 100mV
from the CV voltage a new charge cycle will begin. The
timer function also protects against charging faulty bat-
teries by turning off if the pre-charge time exceeds 1/4
of the total programmed charge duration.
The SC805 also provides battery detection, and a bat-
tery NTC thermistor interface to disable charging when
the battery temperature exceeds safe-to-charge limits.
The SC805 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.
Cellular phones
PDA’s
Handheld meters
Charging stations
USB chargers
Digital cameras
Programmable current source