ISL6298-2CR3Z Intersil, ISL6298-2CR3Z Datasheet - Page 10

• Manufacturer Part Number: ISL6298-2CR3Z
• Description: IC CHARGER LI-ION 4.2V 3X3 10DFN
• Manufacturer: Intersil

Specifications of ISL6298-2CR3Z

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 4.3 V ~ 6.5 V
• Operating Temperature: -20°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 10-VFDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Theory of Operation
The ISL6298 is an integrated charger optimized for low-
capacity single-cell Li-ion or Li-polymer batteries. It charges
a battery with the constant current (CC) and constant voltage
(CV) profile. The charge current is trimmed to have better
than 10% accuracy at 250mA and is programmable up to
450mA. The charge voltage has 1% accuracy.
Figure 20 shows the typical operating waveforms after
power on. The power is applied at t
reaches the power-on reset (POR) threshold at t
pin starts to output a 2.8V supply. This supply also powers
the internal control circuit. The POR initiates a charge cycle.
Six different ways can initiate a charge cycle, as listed in
Table 1.
A charge cycle goes through a trickle mode (t
constant current (CC) mode (t
(CV) mode (t
(t
battery for an excessively long time. At the end of the fast
charge time (t
must reach an end-of-charge (EOC) condition before the
termination; otherwise, the charger issues a fault indication
through the FAULT pin. The charger issues a logic low signal
TABLE 1. EVENTS THAT LEADS TO A NEW CHARGE CYCLE
STATUS
2
I
CHARGE
FAULT
#
1
2
3
4
5
6
to t
VBAT
V2P8
VIN
5
Power on Reset
The VIN pin voltage drops below the VBAT pin voltage and
then rises back above the VBAT pin voltage
A new battery being inserted (detected by TEMP pin)
The battery voltage drops below a recharge threshold after
completing a charge cycle
recovery from a battery over-temperature fault
the EN pin is toggled from GND to floating
FIGURE 20. TYPICAL OPERATING WAVEFORMS
) is programmed by users to prevent charging a faulty
t
0
3
5
to t
), the charger is terminated. The charger
t
1
5
t
). The total fast charge (CC and CV) time
2
POR Threshold
Charge Cycle
1/8 TIMEOUT
15 Cycles to
2.8V V
t
3
10
2
MIN
EVENT
t
4
V
to t
RECHRG
t
5
0
3
. When the input voltage
I
) and a constant voltage
MIN
t
6
t
7
Charge Cycle
15 Cycles
1
to t
1
, the V2P8
2
), a
t
8
ISL6298
at the STATUS pin at the beginning of a charge cycle. When
the EOC condition is reached, the STATUS rises to high, as
shown at t
After termination, if the battery voltage drops below a
recharge threshold (t
take place. The total time for the recharge cycle is the total
fast charge time (t
negligible in a recharge cycle. More detailed description for
the operation is given below.
Power on Reset (POR)
The ISL6298 resets itself as the input voltage rises above
the POR rising threshold. The V2P8 pin outputs a 2.8V
voltage, the internal oscillator starts to oscillate, the internal
timer is reset, and the charger begins to charge the battery.
The two indication pins, STATUS and FAULT, indicate a
LOW and a HIGH logic signal respectively. Figure 20
illustrates the startup of the charger between t
The ISL6298 has a typical rising POR threshold of 3.4V and
a falling POR threshold of 2.4V. The 2.4V falling threshold
guarantees charger operation with a current-limited adapter
to minimize the thermal dissipation. See more details on
using a current-limited adapter in the ISL6292 datasheet,
available at http://www.intersil.com.
Internal Oscillator
The internal oscillator (see the Block Diagram) establishes a
timing reference. The oscillation period is programmable
with an external timing capacitor, C
Applications. The oscillator charges the timing capacitor to
1.5V and then discharges it to 0.5V in one period, both with
10µA current. The period T
A 1nF capacitor results in a 0.2ms oscillation period.
Total Fast Charge Time
The total fast charge time TIMEOUT is also programmed by
the C
oscillation period to set the TIMEOUT, thus,
A 1nF capacitor leads to 14 minutes of TIMEOUT. If a user
needs to set the TIMEOUT to 3.5 hours, a 15nF capacitor is
required. The charger must reach EOC before the charger
terminates, otherwise, a TIMEOUT fault will be issued.
Trickle Charge Time
The trickle charge time is limited to 1/8 of TIMEOUT. If the
trickle charge time (t
fault will be issued. The end of trickle charger is determined
by the battery voltage staying above the trickle charge
threshold (given in the Electrical Specification) for 15
consecutive cycles of T
T
TIMEOUT
OSC
TIME
=
0.2 10
4
. A 22-stage binary counter increments each
.
=
⋅
2
22
6
⋅
⋅
7
C
T
to t
TIME
OSC
1
6
to t
in Figure 20), a re-charge cycle will
8
OSC
=
). The trickle charge time is
2
14
) exceeds the limit, a TIMEOUT
OSC
; therefore, the minimum time
⋅
(
C
----------------- -
sec
1nF
TIME
is:
onds
TIME
)
, as shown in Typical
(
minutes
0
to t
)
March 9, 2006
2
.
FN9173.4
(EQ. 1)
(EQ. 2)