ISL6292BCR Intersil, ISL6292BCR Datasheet - Page 10

• Manufacturer Part Number: ISL6292BCR
• Description: IC BATT CHRGR LI-ION 4.2V 16-QFN
• Manufacturer: Intersil

Specifications of ISL6292BCR

• 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: Contains lead / RoHS non-compliant

create a hysteresis for each comparator respectively. The
DT pin is shorted to GND via the internal Q3 MOSFET when
the charger is not charging, resulting in the equivalent circuit
shown in Figure 7 (A). The on-resistance of Q3 is typically
50Ω and is negligible compared to the external resistors.
When the charger starts to charge, Q3 is turned off to set a
higher temperature range determined by the external
resistor R
The DT pin allows the user to set up a higher shut down
ambient temperature after the charger starts up.
The selection of R
described in the ISL6292 datasheet. The selection R
follows the following equation:
R
where R
R
shows the temperature windows before, during, and after
charging. Before and after charging, the temperature window
is -5°C to 45°C with 5°C hysteresis. During charging, the
high temperature limit changes to 45°C + ∆T. If this limit is
exceeded, the charger is stopped and the temperature has
to come back to below 40°C for the charging to be allowed
again. The low temperature limit is also increased. However,
the R
at low temperature, therefore, the influence on the
temperature threshold is not as much as at high
temperature. Typically, the low temperature threshold is
raised by less than 2°C, as shown in Figure 8.
Charge Current Thermal Foldback
The thermal foldback function monitors the die temperature
and reduces the charge current when the die temperature
rises above 100°C to prevent further temperature rise. The
charge current reduces at a rate of 100mA/°C after
exceeding 100°C. For a charger with the constant charge
current set at 1A, the charge current is reduced to zero when
D
T,@(45
FIGURE 7. EQUIVALENT CIRCUITS FOR THE NTC DIVIDER
= R
D
R
T,@45
Q3
typically has a much lower resistance than the NTC
°
T,@45
C + ∆T)
D
. The equivalent circuit is shown in Figure 7 (B).
V2P9
TEMP
(A)
DT
GND
°
(A) BEFORE CHARGING STARTS
(B) DURING CHARGING.
C
°
C
- R
is the resistance at 45°C + ∆T. Figure 8
is the thermistor resistance at 45°C and the
U
T,@(45
R
and R
T
R
U
°
T
C + ∆T)
uses the same procedure
10
V2P9
TEMP
GND
(B)
R
T
R
R
U
D
D
ISL6292B
the internal temperature rises to 110°C. The actual charge
current settles between 100°C to 110°C.
Usually the charge current should not drop below I
because of the thermal foldback. For some extreme cases if
that does happen, the charger does not indicate end-of-
charge unless the battery voltage is already above the
recharge threshold.
2.9V Bias Voltage
The ISL6292B provides a 2.9V voltage for biasing the
internal control and logic circuit. This voltage is also
available for external circuits such as the NTC thermistor
circuit. The maximum allowed external load is 2mA.
EN Pin
The EN pin allows direct interface to the battery ID pin of a
battery pack. The battery ID pin is connected with a resistor
of a value less than 27kΩ to ground inside the battery pack.
When the battery is not attached, the EN pin is pulled up by
an internal source to the V2P9 pin to disable the charger.
The 2.9V internal regulator is on as long as the input power
is applied, independent of the EN input. Table 2 summarizes
the status of each pin when the IC is disabled.
V2P9
RED
GRN
DT
IREF
IMIN
TEMP
45
TABLE 2. SUMMARY OF PIN BEHAVIOR WHEN THE IC IS
FIGURE 8. BOARD TEMPERATURE MONITORING WHEN
PIN
o
C + ∆T
-5
45
40
0
o
o
o
o
C
C
C
C
Outputs 2.9V.
High impedance
High impedance
Low impedance
Outputs 0.8V
Outputs 0.8V
The temperature monitoring circuit remains functioning.
NOT CHARGE
DISABLED BY THE EN PIN
THE CHARGE IS NOT CHARGING, THE
TEMPERATURE WINDOW IS -5°C AND 45°C.
ONCE THE CHARGER STARTS, THE
TEMPERATURE WINDOW IS 1.X°C TO 45°C+ ∆T.
BEHAVIOR
CHARGE
Less than 2
NOT CHARGE
°
C
MIN
April 19, 2005
FN9139 .1