®
ISL6291
Data Sheet
May 2, 2005
FN9102.2
Li-ion/Li Polymer Linear Battery Charger
The ISL6291 provides a low-cost integrated charger solution
for single-cell Li-ion and Li Polymer rechargeable batteries.
No external pass element, current sensing resistor, or
reverse blocking diode is required with this solution.
The ISL6291 is a constant-current (CC)/constant-voltage
(CV) charger. The constant charge current is programmable
up to 2.0A with an external signal resistor. An internal
trimmed current-sense circuit guarantees 10% accuracy,
with no bulky external current-sense resistor. The constant
voltage is either 4.1V or 4.2V. The charger always
preconditions the battery with 1/10 of the programmed
charge current at the beginning of a charge cycle, until it
verifies that the battery can be fast-charged. A safety timer
prevents over-charging a dead battery. The charging
terminates as the charge current falls below the
programmed minimum current during the CV mode. The
charger automatically re-charges the battery when the
battery voltage drops below a recharge threshold. A simple
interface with an NTC thermistor avoids charging the battery
outside a programmable temperature window. A thermal-
foldback feature of the ISL6291 guarantees safe operation
when the printed circuit board space is limited for thermal
dissipation. The charger reduces the charge current
automatically, as the internal temperature rises above a
preset level, to prevent further temperature rise.
When the wall adapter is not present, the ISL6291 draws
less than 1
µ
A current from the battery. Two logic outputs
provide the charging status and fault information, and an
easy interface to system logic. A V2P8 pin outputs a 2.8V
reference voltage that can be used to bias other circuits, or
as an indication for the adapter presence.
The ISL6291 is packed in a thermally enhanced 5x5 QFN
package. See the Technical Brief TB389 given in the Related
Literature for more information related to the package.
Features
• Integrated Linear Pass Element
• Integrated Charge Current Sensor
• No External Reverse Blocking Diode Required
• 1% Voltage Accuracy
• Programmable Current Limit Up to 2.0A
• Programmable End-of-Charge Current
• Trickle Charge an Over Discharged Battery
• Charge Current Thermal Foldback
• Simple Interface for Low-Cost Thermistor
• Accepts USB Bus Power
• Ambient Temperature Range: -20°C to 70°C
• Thermally-Enhanced 5x5 QFN Package (θ
JA
= 33°C/W)
• Pb-Free Available (RoHS Compliant)
Applications
• Handheld Devices
• Cell Phones
• PDAs
• Stand-Alone Chargers
• USB Bus-Powered Chargers
Related Literature
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
• Technical Brief TB389 “PCB Land Pattern Design and
Surface Mount Guidelines for QFN Packages”
Pinout
ISL6291 (QFN)
TOP VIEW
VBAT
14
VBAT
13
12
11
10
9
5
GND
6
TOEN
7
EN
8
V2P8
VBAT
TEMP
IMIN
IREF
VIN
16
VIN
FAULT
STATUS
TIME
1
2
3
4
VIN
15
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2005. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
Absolute Maximum Ratings
Supply Voltage (VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.5V
Signal Input Voltage (EN, TOEN). . . . . . . . . . . . . . . . . . . . . . . . 3.3V
ESD Rating
Human Body Model (Per MIL-STD-883 Method 3015.7) . . . . .1kV
Machine Model (Per EIAJ ED-4701 Method C-111) . . . . . . . .200V
Thermal Information
Thermal Resistance
θ
JA
(°C/W)
θ
Jc
(°C/W)
QFN Package (Notes 1, 2) . . . . . . . .
36
5.5
Maximum Junction Temperature (Plastic Package) . . . . . . . . 150°C
Maximum Storage Temperature Range . . . . . . . . . . . -65°C to 150°C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300°C
Recommended Operating Conditions
Ambient Temperature Range . . . . . . . . . . . . . . . . . . . .-20°C to 70°C
Supply Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.35V to 10V
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1.
θ
JA
is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See
Tech Brief TB379.
2. For
θ
JC
, the “case temp” location is the center of the exposed metal pad on the package underside.
Electrical Specifications
PARAMETER
POWER-ON RESET
Rising VIN Threshold
Hysteresis
STANDBY CURRENT
VBAT Pin Sink Current
VIN Pin Supply Current
VOLTAGE REGULATION
Output Voltage
Output Voltage
Dropout Voltage (Note 3)
CHARGE CURRENT
Constant Charge Current (Note 4)
Trickle Charge Current
End-of-Charge Threshold
RECHARGE THRESHOLD
Recharge Voltage Threshold
Recharge Voltage Threshold
Typical Values Are Tested at 25°C and 5V Input, Maximum and Minimum Values Are Guaranteed Over 0°C to
70°C Ambient Temperature with a Supply Voltage in the Range of 4.35V to 10V, Unless Otherwise Noted.
SYMBOL
TEST CONDITIONS
MIN
-
-
I
STANDBY
I
VIN
V
CH
V
CH
V
DROP
I
CHARGE
I
TRICKLE
I
EOC
V
RECHRG
V
RECHRG
V
MIN
V
TMIN
V
TMAX
V
RMV
T
FOLD
G
FOLD
C
TIME
= 15nF
V2P8 = 3V
R
IMIN
pin = 80kΩ
ISL6291-2
ISL6291-1
VIN < VBAT
VIN > VBAT and EN = floating
ISL6291-1
ISL6291-2
VBAT = 4.2V, charge current = 0.5A
R
IREF
= 80kΩ, VBAT = V
CH
- 100mV
-
-
4.059
4.158
-
0.9
-
-
-
-
-
1.425
.260
-
85
-
2.1
2.0
-
Pin Voltage = 0.8V
5
TYP
3.9
160
-
1
4.10
4.20
-
1.0
100
100
4.00
3.90
3.0
1.505
.305
2.25
100
40
3
-
-
-
MAX
4.3
-
1
-
4.141
4.242
250
1.1
-
-
-
-
-
1.575
.340
-
115
-
3.9
-
0.8
-
UNITS
V
mV
µA
mA
V
V
mV
A
mA
mA
V
V
V
V
V
V
°C
mA/°C
ms
V
V
mA
TRICKLE CHARGE THRESHOLD
Trickle Charge Threshold Voltage
TEMPERATURE MONITORING
Low Battery Temperature Threshold
High Battery Temperature Threshold
Battery Removal Threshold
Charge Current Foldback Threshold (Note 3)
Current Foldback Gain
OSCILLATOR
Oscillation Period
LOGIC INPUT AND OUTPUT
Logic Input High
Logic Input Low
STATUS/FAULT Sink Current
NOTES:
3. Guaranteed by design, not tested.
4. The actual current may be affected by the thermal fold-back or the dropout voltage.
5
FN9102.2
May 2, 2005