BQ2084-V140_14 Datasheet, PDF (27/64 Pages) Texas Instruments – SBS v1.1-COMPLIANT GAS GAUGE FOR USE WITH THE bq29312

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bq2084-V140
SLUS664B – JULY 2005 – REVISED AUGUST 2006
Figure 3. Shutdown Flow Chart in Normal Operation
SBS MAC command 0x05
received
No
SBS.Current( ) <= 0?
Yes
No
Pack voltage < Vpack
threshold ?
Yes
bq2084 Enters Shutdown
Figure 4. Shutdown Flow Chart in SBS MAC
Reset Conditions
On power up, the entire IC is reset and data is loaded from Data Flash to configure the SBS Data and the
battery management solution. On a partial reset (loss of VCC but RBI holds RAM valid), a limited number of
locations are taken. These actions are the following:
• The AFE registers are rewritten.
• PackStatus() EDV2 flag is cleared.
• BatteryStatus() DISCHARGING flag is cleared.
• The charger and alarm broadcast period is set to 10 seconds between broadcasts.
COMMUNICATION
The bq2084-V140 includes an SMBus communication port. The SMBus interface is a 2-wire bidirectional
protocol using the SMBC (clock) and SMBD (data) pins. The communication lines are isolated from V_CC and
may be pulled up higher than VCC. Also, the bq2084-V140 does not pull these lines low if V_CC to the part is
zero. The communication ports allow a host controller, an SMBus compatible device, or other processor to
access the memory registers of the bq2084-V140. In this way a system can efficiently monitor and manage the
battery.
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