SI9731DB

Si9731 is a chemistry independent battery charger designed to pulse charge 1-cell to 3-cell NiCd/NiMH or 1-cell Li-ion batteries. Battery charging is accomplished under direct control from the system processor. An internal low RDS(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 process. For charging Li-ion batteries, Si9731 includes a precision 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).

• 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 of external components
• ESD protection to 4 kV on charger input and battery output
• TSSOP-16 package (1.2 mm maximum height)
• Halogen-free according to IEC 61249-2-21 definition
• Compliant to RoHS Directive 2002/95/EC