ISL6297CRZ Intersil, ISL6297CRZ Datasheet - Page 9

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

Specifications of ISL6297CRZ

• 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

charge state machine is reset, the V2P9 pin outputs 2.9V,
the open-drain MOSFET on the DT pin is turned on, and the
ambient temperature monitoring circuit starts to function.
EN Pin
If all other charge conditions are met, pulling the EN pin low
starts the ISL6297 charge operation. In a typical application,
EN connects to the ID pin of a battery pack. Inside the
battery pack the ID pin connects to ground through a
resistance of less than 27kΩ. When the battery is not
attached to the charger, the ISL6297 internally pulls the EN
pin high to disable the charger. An RC filter on the ISL6297
EN input improves the charger ESD protection.
Table 1 summarizes the status of each pin when the EN pin
disables the IC.
Plug-in Indication
After power is applied to the ISL6297 and V
POR threshold, the LEDs provide a Plug-in Indication
sequence. First the RED LED turns on for 500ms, then the
GREEN LED turns on for 500ms, then both turn on for
500ms (giving a YELLOW indication), and finally all the
LEDs turn off.
The ISL6297 turns on an LED by pulling the output line LOW
with a constant current of 10mA (typical). A typical bi-color
LED needs no series resistor for the LED connection,
however, current can be minimized by adding a serial
resistor in each LED path.
Idle Condition and Battery Connection
Once V
temperature is within the allowed range the ISL6297 is ready
to start the charge operation. Charging is initiated by
plugging in the battery, which pulls the EN pin low.
Connection Verification
The EN pin going low starts a 500ms delay. After the delay,
the ISL6297 turns on the charger for 70ms with a trickle
charge current and an output voltage of V
connected, the VSEN voltage will go up to approximately
VIN. If no battery is detected after the 70ms period, the
ISL6297 terminates the charge operation, turns off the
V2P9
RED
GRN
DT
IREF
IMIN
TEMP
TABLE 1. SUMMARY OF PIN BEHAVIOR WHEN THE IC IS
PIN
IN
is greater than (V
Outputs 2.9V.
High impedance.
High impedance.
Low impedance.
Outputs 0.8V.
Outputs 0.8V.
The temperature monitoring circuit remains functioning.
DISABLED BY THE EN PIN
BAT
9
BEHAVIOR
+ 50mV) and the
IN
IN
. If no battery is
exceeds the
ISL6297
output voltage, and sets the LEDs off. The device remains in
this state until the EN pin is toggled or the device goes
through a power cycle (see Figure 5).
If the battery is connected within the 70ms open battery
detect period, the voltage on VSEN pin needs to drop below
the (falling) threshold of about 4.3V before the end of the
70ms period. If not, then the battery has not been properly
connected and an open battery connection fault condition
exists, requiring a power cycle or a toggle of EN.
After the 500ms delay, if a battery is connected, the VSEN
voltage will remain below the 4.4V threshold and the
ISL6297 assumes that the battery is connected. The device
turns on the Red LED to indicate a charge operation and
starts a short circuit detection (see Figure 4).
If the battery positive terminal comes loose and reconnects
after this time, the charge operation sequence continues, but
the LED indicates an end of charge condition, regardless of
the state of charge.
Short Circuit Detection
To detect a short circuit condition the ISL6297 forces the
trickle charge current to the battery. If, after 384 cycles, the
battery voltage is below 1V, the ISL6297 considers the
battery or connection to be short-circuited. In this condition,
the charger turns off and a flashing yellow indicator displays
the occurance of this “non-temperture” fault.
To clear a short circuit fault condition requires that the enable
pin be toggled, by removing the battery pack, or by cycling
the power on the charger.
Trickle Charge
If there is no short circuit the voltage is higher than 1V and
the charge operation continues with a trickle charge. In the
trickle charge, the ISL6297 applies 10% of the programmed
current to the battery. If the voltage on the cell is greater than
2.8V after 15 clock cycles, then the ISL6297 applies the full
constant current charge to the cell. However, if the voltage
on the cell does not rise above 2.8V in one eighth (1/8) of the
TIMEOUT period, then a non-temperature fault occurs and
the charger is turned off. A flashing yellow indicator
announces this condition.
July 30, 2007
FN9215.2