SI9731

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 Si9731 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.