bq20z80-V101
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SLUS625D–SEPTEMBER 2004–REVISED OCTOBER 2005
When transitioning from [FCHG] to [TCHG2] or from [TCHG2] to [TCHG1] the there is additional temperature
hyteresis of DF:Temp Hys.
SBS.ChargingStatus( ) [TCHG2, TCHG1] are also cleared when another charging mode is entered, a protection
condition is detected, or the battery is removed while the DF:Operation Cfg B [NR] is set.
However, if DF:DeltaTemp is set to 0, SBS.ChargingCurrent( ) remains DF:Fast Charge Current during fast
charge.
SIZE
(BYTES)
DEFAULT
VALUE
NAME
CLASS / SUBCLASS
FORMAT
VALID RANGE
UNITS
Delta Temp
Charge Control / Fast Charge Config (34)
Integer
0 to 500
0.1°C
50
Charge Suspend Mode
If charging has begun, the bq20z80 suspends charging when:
•
•
SBS.AverageCurrent( ) is > the DF:Chg Current Threshold, AND
SBS.Temperature( ) is < DF:Charge Suspend Temp Low AND is > DF:Charge Suspend Temp High.
If DF:Operation Cfg B [CHGSUSP] is set, the CHG FET and ZVCHG FET (if used), are turned off when the
bq20z80 is in charge-suspend mode.
When charging is suspended, SBS.ChargingCurrent( ) is set to 0, and SBS.ChargingStatus( ) [CHGSUSP] is set.
To return to normal charging, SBS.Temperature( ) must be:
•
≥ DF:Charge Inhibit Temp Low + DF:Temp Hys, AND
•
≤ DF:Charge Inhibit Temp High–DF:Temp Hys.
The bq20z80 clears SBS.ChargingStatus(
)
[CHGSUSP] when this condition is met, and sets
SBS.ChargingCurrent( ) according to the appropriate charging mode entered. The FETs are also returned to their
previous state at this time.
SBS.ChargingStatus( ) [CHGSUSP] is also cleared when a protection condition is detected, or when the battery
is removed while DF:Operation Cfg B [NR] is cleared.
SIZE
(BYTES)
DEFAULT
VALUE
NAME
CLASS / SUBCLASS
FORMAT
VALID RANGE
UNITS
Charge Suspend Temp Low
Charge Suspend Temp High
–400 to 1200
–400 to 1200
–50
550
Charge Control /
Fast Charge Config (34)
Signed Int
2
0.1°C
Pulse Charging
Pulse charging is part of the fast-charging mode and is a loop. During the loop, the measured cell voltages are
calculated every 250 ms. This data is not reported via the SBS.CellVoltagex( ) commands.
The pulse-charging loop is entered when the maximum cell voltage is ≥ DF:Max OFF Voltage, OR maximum cell
voltage is ≥ DF:Turn OFF Voltage for DF:Max ON Pulse Time. When these conditions are met, the CHG FET is
turned off, and the SBS.ChargingStatus( ) [PULSE. PULSE_OFF] are set.
If the maximum cell voltage is < DF:Turn ON Voltage, AND the CHG FET is off for DF:Min OFF Pulse Time, the
CHG FET is turned on and SBS.ChargingStatus( ) [PULSE_OFF] cleared.
59
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