SC805A Datasheet, PDF (1/17 Pages) Semtech Corporation – Miniature Integrated High Current Lithium-Ion Battery Charger

SC805A
Miniature Integrated High Current
Lithium-Ion Battery Charger
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The SC805A is a fully integrated, single cell, constant-
current (CC)/constant-voltage (CV) Lithium-Ion battery
charger in a tiny 3x3 mm thermally enhanced lead-free
MLP package. The SC805A can operate as a stand-alone
charger or in conjunction with a Power Management Inte-
grated Circuit (PMIC).
The SC805A 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
SC805A switches to CV regulation mode. In this mode
the output current decays as the battery charges until the
termination current is reached and the SC805A signals the
charge cycle is complete. The SC805A can be configured
to continue charging for a pre-determined time before
turning off, or to turn off immediately upon termination.
After turning off its output, the SC805A 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 batteries by
turning off if the pre-charge time exceeds ¼ of the total
programmed charge duration.
The SC805A also provides battery detection, and a battery
NTC thermistor interface to disable charging when the
battery temperature exceeds safe-to-charge limits.
 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 MLPD package
 Programmable pre-charge, fast-charge and
termination current
 Battery voltage controlled to 1% accuracy
 Built-in timer for protection and complete charging
 NTC interface with battery detection
 Soft-start to reduce adapter in-rush current
 Up to 1A continuous charge current
 Input voltage range from 3V to 6V allows seamless
charging from current limited adapter
ApPprloicviadetisoandsapter voltage VCCIL to power external
accessories
 Battery present detection and output indicator
 Operates in charger or LDO-Mode without battery
 0.1µA battery drain current in shutdown and monitor
modes
 Over-current protection in all charging modes
 CHRGB output communicates charging and
end-of-charge cycle
*US Patent 6,836,095
Applications
The SC805A can also function as a general purpose current
source or as a current source for charging nickel-cadmium
(NiCd) and nickel-metal-hydride (NiMH) batteries.
Typical Application Circuit
 Cellular Phones
 PDAs
 Handheld Meters
 Charging Stations
 USB Chargers
 Digital Cameras
 Programmable Current Source
CHARGER VIN
C1
1µF
Adapter
Present
Indicator
D1
LED
R1
3.01k
R2
3.01k
RT1
Thermistor
SC805A Typical Application Circuit
SC805A
1 VCC
VOUT 3
2 VCCIL CHRGB 10
7 EN/NTC ITERM 5
8 NOBAT IPRGM 4
9 RTIME
GND 6
R4
3.01k
R3
39.2k
R5
3.01k
Charge
Complete
Indicator
D2
LED
R6
1k
D3
LED
R7
1k
Charging
Indicator
BATTERY
C1
2.2µF
March 3, 2007

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