ISL6297 Intersil Corporation, ISL6297 Datasheet - Page 10

• Manufacturer Part Number: ISL6297
• Description: Li-ion/Li Polymer Battery Charger
• Manufacturer: Intersil Corporation

Charge Current and R
When the ISL6297 is used as a traditional linear charger, the
RIREF sets the constant charge current. When working with a
dual-mode, current-limited supply, the CC current is determined
by the supply limited current ILIM. IREF needs to be
programmed higher than ILIM and is used as an overcurrent
protection. Taking into account the tolerance of both the ILIM
and IREF, it is recommended the IREF be programmed at least
30% higher than the ILIM. IREF can be calculated by using the
following equation:
VSEN
I
CHG
EN
VSEN
LEDs
V2P9
I
GRN
RED
CHG
POR required before charge
VIN
EN
DT
FIGURE 5. OPEN BATTERY DETECTED
Charge terminates. EN or
sequence starts again
4.4V
V
IN
off
IREF
500ms
10
Selection
500ms
Battery connected here, but voltage
remains above the battery detect
(falling) threshold
Red
FIGURE 4. EVENT SEQUENCE AT POWER UP
70ms
- Open battery detected
4.3V
Trickle current
500ms
Green
500ms
Trickle current
Yellow
ISL6297
500ms
The trickle charge current is 10% of I
The ISL6297 has a comparator with a 50mV offset voltage to
ensure the input voltage is higher than the battery voltage
before charging starts (see the Block Diagram). This
condition, coupled with an R
requires I
is 1.5A.
EOC Current and R
The EOC current level is programmed by the I
can be calculated by the following equation:
The EOC current has a programming range up to 400mA.
To qualify as an EOC condition, the battery voltage must be
above the recharge threshold given in the Electrical
Specification table and the charge current needs to drop
below the I
Connection Verification
Short Circuit Test
I
I
I
MIN
REF
Trickle
off
LIM
=
=
MIN
=
70ms
----------------
R
be higher than 125mA. The upper limit for I
---------------- -
R
0.8V
0.8V
IMIN
IREF
level for 3 to 4 cycles of the internal oscillator.
500ms
---------------- -
R
4.4V
0.8V
IREF
×
×
10
10
×
IMIN
4
10
5
( )
( )
A
A
4
( )
A
DS(on)
Selection
Charge Starts
Check if
BAT > 1V
If not: FAULT
Red
of about 400mΩ (max)
384 cycles
max.
REF
Battery (+)
connection
verified
, that is,
MIN
March 20, 2007
pin and
FN9215.1
(EQ. 3)
(EQ. 4)
(EQ. 5)
LIM