© 2008 Semtech Corporation

POWER MANAGEMENT

1

SC802/SC802A

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 — 0.1

μA

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.

CHARGER VIN

Battery

Thermistor

1μF

2.2μF

BAT.

CHARGE

CHARGER

PRESENT

SC802/SC802A

VCC1

BSEN

IPRGM

EN_NTC

ITERM

VOUT2

RTIME

CHRGB

VPRGM

CPB

RFGND

BIPB

VCC2

GND

VOUT1

AFC

Typical Application Circuit

October 30, 2008