bq20z80-V101
www.ti.com
SLUS625D–SEPTEMBER 2004–REVISED OCTOBER 2005
2nd LEVEL PROTECTION FEATURES
The bq20z80 provides features that can be used to indicate a more serious fault via the SAFE and SAFE
outputs. These outputs can be used to blow an in-line fuse to permanently disable the battery pack from charge
or discharge activity.
Actions on Detection of 2nd Level (Permanent) Failure
When the bq20z80 SBS.PFStatus( ) changes from 0x00 to indicate a permanent failure then the following actions
are taken in sequence.
•
•
•
CHG, DSG, and ZVCHG FETs are turned OFF.
SBS.BatteryStatus( ) [TCA, TDA] are set.
A backup of SBS data is stored to data flash including SBS.Voltage( ), SBS.CellVoltage1( ),
SBS.CellVoltage2( ), SBS.CellVoltage3( ), SBS.CellVoltage4( ), SBS.Current( ), SBS.Temperature( ),
SBS.BatteryStatus( ), SBS.RemaingCapacity( ) , SBS.SafetyStatus( ), SBS.ChargingStatus( ), AFE.Data
(complete memory map).
•
•
•
•
Data Flash write access is then disabled, but the data flash can be read.
SBS.ChargingCurrent( ) and SBS.ChargingVoltage( ) are set to 0.
The appropriate bit in DF:PF Flag 1 is set.
If the appropriate bit in DF:Permanent Fail Cfg is set, then 0x3672 is programmed to DF:Fuse Flag, the
SAFE pin is driven and latched low, and the SAFE pin is driven and latched high.
•
SBS.SafetyStatus( ) [PF] is set.
SIZE
(BYTES)
DEFAULT
VALUE
NAME
CLASS / SUBCLASS
FORMAT
VALID RANGE
UNITS
PF Flags 1
Fuse Flag
0x0000 to 0xffff
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
1
N/A
N/A
mV
0x0000
0x0000
0
Hex
0x0000 or 0x3672
PF Voltage
PF C1 Voltage
PF C2 Voltage
PF C3 Voltage
PF C4 Voltage
PF Current
mV
0
0 to 65535
mV
0
Integer
mV
0
mV
0
2nd Level Safety / Device
Status Data (96)
–32768 to 32767
–9999 to 9999
0x0000 to 0xffff
mA
0
PF Temperature
PF Batt Stat
PF RC-mAh
PF RC-10mWh
PF Chg Status
PF Safety Status
PF Flags 2
0.1°C
N/A
mAh
10mWh
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0
Hex
0x0000
0
Integer
0 to 65535
0
0x0000 to 0xffff
0x0000
0x0000
0x0000
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
0x00
Hex
AFE Status
0x00 to 0xff
0x00 to 0xff
0x00 to 0xff
0x00 to 0xff
0x00 to 0xff
0x00 to 0xff
0x00 to 0xff
0x00 to 0xff
0x00 to 0xff
AFE Output
AFE State
AFE Function
AFE Cell Select
AFE OLV
2nd Level Safety / AFE Regs
(97)
Hex
AFE OLT
AFE SCC
AFE SCD
20
TI [ TEXAS INSTRUMENTS ]
