FEATURES

• Over-Charge Protection

• Over-Discharge Protection

• Short Circuit Current Limiting

• Battery Open-Circuit Center Tap Protection

• Cell Voltage Balancing

• Undervoltage Lockout

• Individual Cell Voltage Monitoring

• Low Operating Current (30 μA) and Shutdown Current

(1 μA)

• Internal N-Channel MOSFET Driver

• High Noise Immunity

• Accurate (± 1.19 ) Over-Charge Voltage Detection

• Four Different Cell Types Covered

DESCRIPTION

The Si9730 monitors the charging and discharging of dualcell

lithium-ion battery packs (carbon or coke chemistry)

ensuring that battery capacity is fully utilized while ensuring

safe operation. The Si9730 provides protection against overcharge,

over-discharge, and short circuit conditions which

are hazardous to the battery and the environment.

Battery voltages of each individual cell are monitored at the

center-tap connection by an internal A/D converter through

the VC pin. If one or both of the cells is determined to be

overcharged, an internal cell balancing network bleeds off

current at 15 μA until both cells are charged to the same

maximum level. Depending on the condition of each cell, the

Si9730 will switch two external source-connected N-Channel

MOSFETs on or off to allow the cells to be charged or to provide

current to the load.

The Si9730 is available in an 8-pin SOIC package with an

operating temperature range of - 25 to 85 °C. The Si9730 is

available in both standard and lead (Pb)-free packages.