5

FN9174.4

July 9, 2007

Description

The ISL6294 charges a Li-ion battery using a CC/CV profile.

4.2V. If the battery voltage is below a typical 2.55V trickle-

charge threshold, the ISL6294 charges the battery with a

above the trickle charge threshold. Fast charge CC mode is

the cell voltage rises to 4.2V. When the battery voltage

reaches 4.2V, the charger enters a CV mode and regulates

the battery voltage at 4.2V to fully charge the battery without

the risk of over charge. Upon reaching an end-of-charge

(EOC) current, the charger indicates the charge completion

with the CHG pin, but the charger continues to output the

4.2V voltage. Figure 4 shows the typical charge waveforms

after the power is on.

FIGURE 3. BLOCK DIAGRAM

EN

+115°C

DIE

TEMP

VIN

PPR

EN

GND

CHG

IMIN

IREF

BAT

200k

BAT

POR

CHARGE

CONTROL

PRE

REG

VCC

VCC

TRICKLE

CC

CV

4.2V

TIME

2.55V

CHG

CHARGE

CURRENT

CHARGE

VOLTAGE

CHG

INDICATION

76%I

REF

FIGURE 4. TYPICAL CHARGE PROFILE

ISL6294