SI9731 Datasheet, PDF (1/10 Pages) Vishay Siliconix – UP Controlled Battery Charger For 1-Cell Li-ion or 1-Cell to 3-Cell NiCd/NiMH Batteries

Si9731
Vishay Siliconix
µP Controlled Battery Charger
For 1-Cell Li-ion or 1-Cell to 3-Cell NiCd/NiMH Batteries
DESCRIPTION
Si9731 is a chemistry independent battery charger designed
to pulse charge 1-cell to 3-cell NiCd/NiMH or 1-cell Li-ion bat-
teries. Battery charging is accomplished under direct control
from the system processor. An internal low r_DS(on) MOSFET
can be pulsed on and off at varying duty cycle by the system
processor to pulse charge the battery at high charge current
while minimizing heat dissipation. Provision is also made to
trickle charge a discharged battery until the battery is
charged to a high enough voltage to wake up the processor
so that the processor can take control of the charging pro-
cess. For charging Li-ion batteries, Si9731 includes a preci-
sion voltage reference and an error amplifier for constant
voltage (CV) charge mode. The Si9731 is available in lead
(Pb)-free TSSOP-16 package and is classified over the
industrial temperature range (- 40 °C to + 85 °C).
FEATURES
• Pulse Charges 1-Cell Li-ion or 1-Cell to 3-Cell
NiCd/NiMH Batteries
• Integrated MOSFETs With Bi-directional
Reverse Current Blocking in "OFF" Mode
• PWM Controlled Fast Charging Mode
• Low Current Trickle Charge Mode
• Pin Selectable 4.1 V or 4.2 V Charge Termination for
Li-ion
• Constant Voltage (CV) Termination For Li-ion
• Input Over-Voltage Detector with Automatic Shutdown
• External Shutdown
• Under 1 µA Reverse Battery Leakage Current In
Shutdown
• Complete Isolation from Battery to External Power
Supply In Shutdown
• Thermal Shutdown
• Minimum Number 0f External Components
• ESD Protection to 4 kV on Charger Input and Battery
Output
• TSSOP-16 Package (1.2 mm maximum height)
APPLICATIONS
• Cellular Phone Battery Charger
• Personal Digital Assistants
FUNCTIONAL BLOCK DIAGRAM
V_CHARGER
ON/OFF
TRICKLECHARGEENABLE
CV_MODE
FAST CHARGE
GND
Document Number: 71321
S-60869-Rev. B, 22-May-06
Fast
Charge
Trickle
Charge
Charge Control
V_BAT
B
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4.1/4.2 V_TAP
www.vishay.com
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