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Battery Removed Mode
Shutdown Mode
bq20z80-V101
SLUS625D – SEPTEMBER 2004 – REVISED OCTOBER 2005
On entry to sleep, and if DF:Operation Cfg B [NR] is cleared, the CHG and DSG FETs are turned off, and the
ZVCHG FET is turned off if DF:Operation Cfg A [ZVCHG1, ZVCHG0] are set appropriately. If DF:Operation Cfg
B [NR] is set, the CHG FET is turned off, and the ZVCHG FET is turned off if DF:Operation Cfg A [ ZVCHG1,
ZVCHG0] are set appropriately. However, if DF:Operation Cfg B [NRCHG] is set then the CHG remains on.
Also, on entry to Sleep mode, the auto calibration of the ADC begins. However, if SBS.Temperature( )
is
≤ DF:Cal Inhibit Temp Low and ≥ DF:Cal Inhibit Temp High, Auto Calibration of the ADC is not started on
entry to sleep mode. The activation of auto calibration is not affected by the state of DF:Operation Cfg A
[SLEEP], nor DF:Sleep Voltage Time, nore DF:Sleep Current Time nor SBS.Current( ).
The bq20z80 exits Sleep mode if |SBS.Current( )| is nonzero, OR the SMBC or the SMBD input transitions high,
OR any SBS.OperationStatus( ), SBS.ChargingStatus( ), or SBS.SafetyStatus( ) flags change state.
If DF:Operation Cfg B [NR] is cleared, the bq20z80 exits Sleep mode when PRES is pulled low
(SBS.OperationStatus( ) [PRES] = 1).
SIZE
DEFAULT
NAME
CLASS / SUBCLASS
FORMAT
VALID RANGE
UNITS
(BYTES)
VALUE
Sleep Current
0 to 100
1
mA
10
Sleep Voltage Time
0 to 100
1
s
5
Integer
Sleep Current Time
0 to 255
1
s
20
Power / Power (68)
Bus Low Time
0 to 255
1
s
5
Cal Inhibit Temp High
-400 to 1200
2
0.1
°C
50
Signed Int
Cal Inhibit Temp Low
-400 to 1200
2
0.1
°C
450
The bq20z80 detects the Battery-Removed state when DF:Operation Cfg B [NR] is cleared AND the PRES input
is high (SBS.Operation Status( ) [PRES] = 0).
On entry to Battery-Removed state, SBS.BatteryStatus( ) [TCA, TDA] are set, SBS.ChargingCurrent( ) and
SBS.ChargingVoltage( ) are set to 0, and the CHG and DSG FETs are turned off, and the ZVCHG FET is turned
off if DF:Operation Cfg A [ZVCHG1, ZVCGH0] are set appropriately.
Polling of the PRES pin continues at a rate of once every 1 s.
The bq20z80 exits the Battery-Removed state if DF:Operation Cfg B [NR] is cleared, AND the PRES input is low
(SBS.OperationStatus( ) [PRES] = 1). When this occurs, SBS.BatteryStatus( ) [TCA, TDA] are reset.
The bq20z80 enters Shutdown mode if the following conditions are met:
SBS.Voltage( )
≤ DF:Shutdown Voltage AND SBS.Current( )≤ 0
OR
(SBS.ManufacturerAccess( ) shutdown command received AND SBS.Current( ) = 0) AND Voltage at the
bq29312A Pack pin < DF:Charger Present threshold.
If DF:Operation Cfg B [NR], is set, DF:Charger Present must be > DF:Shutdown Voltage + 6% for correct
operation.
It is also recommended that the value of DF:Charger Present be > 4.3 V x the number of series cells regardless
of the setting of DF:Operation Cfg B [NR].
When the bq20z80 meets these conditions, the CHG, DSG, and ZVCHG FETs are turned off, and the bq29312A
is commanded to shut down. In Shutdown mode, the bq20z80 is completely powered down because its supply is
removed.
To exit Shutdown mode, the voltage at the PACK pin of the bq29312A must be greater than its minimum
operating voltage. When this occurs, the bq29312A returns power to the bq20z80, SBS.OperationStatus( )
[WAKE] is set and the bq29312A configured. The SBS.BatteryMode( ) [INIT] and SBS.OperationStatus( )
[WAKE] are cleared after approximately 1 s when all SBS parameters have been measured and updated.
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