SI9730 Datasheet, PDF (1/14 Pages) Vishay Siliconix – Dual-Cell Lithium Ion Battery Control IC

Si9730
Vishay Siliconix
Dual-Cell Lithium Ion Battery Control IC
FEATURES
D Over-Charge Protection
D Over-Discharge Protection
D Short Circuit Current Limiting
D Battery Open-Circuit Center Tap Protection
D Cell Voltage Balancing
D Undervoltage Lockout
D Individual Cell Voltage Monitoring
D Low Operating Current (30 mA) and Shutdown Current (1 mA)
D Internal N-Channel MOSFET Driver
D High Noise Immunity
D Accurate ("1.19%) Over-Charge Voltage Detection
D Four Different Cell Types Covered
DESCRIPTION
The Si9730 monitors the charging and discharging of dual-cell
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.
overcharged, an internal cell balancing network “bleeds” off
current at 15 mA 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.
Battery voltages of each individual cell are monitored at the
center-tap connection by an internal A/D converter through the
V_C pin. If one or both of the cells is determined to be
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.
FUNCTIONAL BLOCK DIAGRAM AND PIN CONFIGURATION
V_DD
+
V_C1
−
V_C
+
V_C2
−
V_SS
DCO
I_S
Document Number: 70658
S-40135—Rev. F, 16-Feb-04
C
Cell Balancing
Network
A/D
Converter ^OUT
Undervoltage
Lockout
Control
Logic
Timer
C_DELAY
Time Out
CLK
Oscillator
1.2 V_REF
I_LIMIT
S_OUT
V_SS
V_M
GS Generator
V_M
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