SC803 Datasheet, PDF (1/17 Pages) Semtech Corporation – Fully Integrated High Current Lithium-Ion Battery Charger System

SC803
Fully Integrated High Current
Lithium-Ion Battery Charger System
POWER MANAGEMENT
Description
Features
The SC803 is a fully integrated, single cell, constant-cur-
rent constant-voltage Lithium-Ion battery charger man-
agement system. The SC803 has built in intelligence and
extreme functionality. When the battery voltage is below
2.8V the charger operates in a pre-charge mode with a
charging current of up to 125mA based on the ITERM
pin resistor. This pre-charge mode is set to limit power
dissipation due to an undercharged battery. When the
battery voltage exceeds 2.8V, the charger enters a fast
charge mode. In this mode, the SC803 delivers up to
1.5A to the battery based on the IPRGM pin resistor.
The part also features current termination, ending the
charge cycle when the battery is charged and the charge
current drops below the current programmed by the
ITERM pin resistor. In addition, the charge current can
be monitored by the voltage on the IPRGM pin allowing a
microcontroller or ADC to access the current informa-
tion to determine when to externally terminate the charge
cycle. Once the charge cycle is complete and terminates,
the device enters the charge monitor mode where the
output voltage of the battery is monitored. If this voltage
drops below the recharge threshold the device will enter
the fast charge mode again, to bring the battery to its
fully charged state. Both the shutdown and monitor
modes drain no more than 1uA from the battery guaran-
teed.
The output voltage to the battery is controlled to within
1% of the programmed voltage for either 4.1V or 4.2V.
The SC803 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 external termination.
Typical Application Circuit
‹ Fully integrated charger with FET pass transistor,
reverse-blocking diode, sense resistor and thermal
protection
‹ Complete voltage ranges of 4.1V, 4.2V &
adjustable
‹ Programmable precharge, fastcharge & termination
current
‹ Battery voltage controlled to 1% accuracy
‹ Soft-start for step load and adaptor plug-in
‹ Up to 1.5A continuous charge current
‹ Charge current monitor output from microcontroller
or ADC Interface
‹ Input voltages range from 4.2V to 7V
‹ 0.1µA Battery drain current in shutdown and
monitor modes
‹ Operates without a battery in regulated LDO mode
‹ Small 4mm x 4mm 16 lead MLP package
‹ Low thermal impedance of 50°C/watt
‹ Few external components
‹ Over current protection in all charging modes
‹ Over voltage protection with fault pin output
‹ All outputs able to drive LED’s and interface to host
processor
‹ Remote Kelvin sensing at the battery terminal
‹ Small input & output filter capacitors
‹ Status output communicates charging and end of
charge cycle
Applications
‹ Cellular phones
‹ PDA’s
‹ Handheld meters
‹ Charging stations
‹ Handheld computers
‹ Digital cameras
‹ Programmable current source
CHARGER VIN
C1
R1 R2
1uF
14
13
3
7
4
8
6
VCC
CP
VCC
STAT
IPRGM OVP
EN
VPRGM
ITERM BSEN
BIP
VOUT
11
10
9
2
1
16
15
5
GND
NC
VOUT
NC
12
SC803
BATTERY
FAULT
C2
2.2uF
STATUS
CHARGER
PRESENT
Pre
−Charge
Current
=

2.8
R2

•
88
Revision 4, November 2004
Fast
−
Charge
Current
=

1.5
R1

•
1000
1
Termination
Current
=

1.5
R2

•
88
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