ISL6257 Datasheet, PDF (1/22 Pages) Intersil Corporation – Highly Integrated Narrow VDC Battery Charger for Notebook Computers

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Data Sheet
January 17, 2007
ISL6257
FN9288.2
Highly Integrated Narrow VDC Battery
Charger for Notebook Computers
The ISL6257 is a highly integrated battery charger controller
for Li-Ion/Li-Ion polymer batteries. ISL6257 is designed for
Narrow VDC applications where the system power source is
either the battery pack or the regulated output of the charger.
This makes the max voltage to the system equal to the max
battery voltage instead of the max adapter voltage. Operating
at lower system voltage can improve overall efficiency. High
efficiency is achieved in the charger with a synchronous buck
topology. The low-side MOSFET emulates a diode at light
loads to improve the light load efficiency and prevent system
bus boosting.
The constant output voltage can be selected for 2, 3 and 4
series Li-Ion cells with ±0.5% accuracy over temperature. It
can also be programmed between 4.2V + 5% per cell and
4.2V - 5% per cell to optimize battery capacity. When
supplying the load and battery charger simultaneously, the
input current limit for the AC adapter is programmable to
within ±3% accuracy to avoid overloading the AC adapter and
to allow the system to make efficient use of available adapter
power for charging. It also has a wide range of programmable
charging current. The ISL6257 automatically transitions from
regulating current mode to regulating voltage mode.
Ordering Information
PART
NUMBER
(Notes 1, 2)
PART
TEMP
PACKAGE PKG.
MARKING RANGE (°C) (Pb-free) DWG. #
ISL6257HRZ ISL6257HRZ -10 to +100 28 Ld 5x5 QFN L28.5×5
ISL6257HRZ-T ISL6257HRZ -10 to +100 28 Ld 5x5 QFN L28.5×5
Tape & Reel
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100% matte
tin plate termination finish, which are RoHS compliant and compatible
with both SnPb and Pb-free soldering operations. Intersil Pb-free
products are MSL classified at Pb-free peak reflow temperatures that
meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
Features
• ±0.5% Charge Voltage Accuracy (-10°C to +100°C)
• ±3% Accurate Input Current Limit
• ±3% Accurate Battery Charge Current Limit
• ±25% Accurate Battery Trickle Charge Current Limit
• Programmable Charge Current Limit, Adapter Current
Limit and Charge Voltage
• Fixed 300kHz PWM Synchronous Buck Controller with
Diode Emulation at Light Load
• AC Adapter Present Indicator
• Fast Input Current Limit Response
• Input Voltage Range 7V to 25V
• Support 2, 3 and 4 Cells Battery Pack
• Up to 17.64V Battery-Voltage Set Point
• Control Adapter Power Source Select MOSFET
• Thermal Shutdown
• Aircraft Power Capable
• DC Adapter Present Indicator
• Battery Discharge MOSFET Control
• Less than 10µA Battery Leakage Current
• Support Pulse Charging
• Charge any Battery Chemistry: Li-Ion, NiCd, NiMH, etc.
• Pb-Free Plus Anneal Available (RoHS Compliant)
Applications
• Notebook, Desknote and Sub-notebook Computers
• Personal Digital Assistant
Pinout
ISL6257 (28 LD QFN)
TOP VIEW
28 27 26 25 24 23 22
EN 1
21 CSOP
CELLS 2
20 CSIN
ICOMP 3
19 CSIP
VCOMP 4
18 SGATE
FB ⁵
VREF 6
17 _BGATE
16 PHASE
CHLIM 7
15 UGATE
8 9 10 11 12 13 14
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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