ISL6297CRZ-T Intersil, ISL6297CRZ-T Datasheet - Page 11

• Manufacturer Part Number: ISL6297CRZ-T
• Description: IC CHARGER LI-ION POLYMER 16-QFN
• Manufacturer: Intersil

Specifications of ISL6297CRZ-T

• 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: 16-VQFN Exposed Pad, 16-HVQFN, 16-SQFN, 16-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ISL6297CRZ-TTR

Internal Oscillator
The internal oscillator establishes a timing reference. The
oscillation period is programmable with an external timing
capacitor, C
page 4. 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 15nF capacitor results in a 3ms oscillation period. The
accuracy of the period is mainly dependent on the accuracy
of the capacitance and the internal current source.
Total Charge Time and C
The time allowed for the battery to charge before an end of
charge indication is limited to the duration of the TIMEOUT
counter. The TIMEOUT period can be calculated by:
where C
Application” on page 4. A 1nF capacitor leads to 14 minutes
of TIMEOUT. For example, a 15nF capacitor sets the
TIMEOUT to be 3.5 hours. The EOC indication goes active
when the TIMEOUT counter expires, even if the battery has
not reached full charge. At this point, if the voltage is above
4.05V, the recharge mechanism will continue to charge the
cell until the current drops below I
counter expires before the battery reaches 4.05V, then the
t
TIMEOUT
OSC
=
0.2
TIME
IMPEDANCE
=
×
TIME
14
10
is the timing capacitor shown in the “Typical
V
V2P9
GRN
I
6
×
RED
CHG
SEN
V
DT
, as shown in “Typical Application” on
EN
×
C
----------------- -
IN
1nF
C
TIME
TIME
OSC
is:
(
11
minutes
TIME
(
sec
MIN
POR THRESHOLD
onds
Selection
15 CYCLES TO 1/8 TIMEOUT
)
. If the TIMEOUT
)
500ms
2.8V MIN.
CHARGE CYCLE
FIGURE 6. OPERATION WAVEFORMS
TIMEOUT
I
MIN
(EQ. 6)
(EQ. 7)
ISL6297
RECHARGE
end of charge indication goes active, but the charger turns
off. The charger cannot leave this condition without toggling
the enable pin or cycling the power.
The trickle mode charge has a time limit of 1/8 TIMEOUT. If
the battery voltage does not reach V
period, a TIMEOUT fault is issued and the charger turns off
with a flashing Yellow LED indicator. The charger stays in
trickle mode for at least 15 cycles of the internal oscillator
and, at most, 1/8 of TIMEOUT.
Once the ISL6297 detects that the battery reaches the EOC
condition, it resets the TIMEOUT counter. At the end of this
TIMEOUT period, the charger turns off and does not start
again until the battery reaches a recharge condition.
Recharge Threshold
Once the charger reaches an end of charge condition and
the charger turns off, if the battery voltage drops below the
recharge threshold given in the “Electrical Specifications”
table, the charger starts a re-charge cycle. This is identical to
an initial charge cycle, except the indicator remains green.
LED Indications
The LED indicators show a number of conditions. On initial
power on reset, the LEDs sequence through red, green and
yellow. Once the charge begins, the ISL6297 pulls the RED
pin low to drive a red indicator. Once the charge properly
finishes (either when the EOC condition is qualified or when
the TIMEOUT completes) the ISL6297 releases the RED
output and pulls the GRN pin low to drive a green indicator
while the red indicator turns off. The green LED remains on
CHARGE CYCLE
15 CYCLES
I
MIN
MIN
within that time
July 30, 2007
FN9215.2